Auditory motion processing after early blindness · 2016. 2. 28. · 2013; Wolbers, Zahorik, &...

Auditory motion processing after early blindness

Fang Jiang $Department of Psychology University of Washington

Seattle WA USA

G Christopher Stecker $

Department of Speech and Hearing SciencesUniversity of Washington Seattle WA USA

Department of Hearing and Speech SciencesVanderbilt University Medical Center Nashville TN USA

Ione Fine $Department of Psychology University of Washington

Seattle WA USA

Studies showing that occipital cortex responds toauditory and tactile stimuli after early blindness areoften interpreted as demonstrating that early blindsubjects lsquolsquoseersquorsquo auditory and tactile stimuli However it isnot clear whether these occipital responses directlymediate the perception of auditorytactile stimuli orsimply modulate or augment responses within othersensory areas We used fMRI pattern classification tocategorize the perceived direction of motion for bothcoherent and ambiguous auditory motion stimuli Insighted individuals perceived motion direction wasaccurately categorized based on neural responses withinthe planum temporale (PT) and right lateral occipitalcortex (LOC) Within early blind individuals auditorymotion decisions for both stimuli were successfullycategorized from responses within the human middletemporal complex (hMT+) but not the PT or right LOCThese findings suggest that early blind responses withinhMTthorn are associated with the perception of auditorymotion and that these responses in hMTthornmay usurpsome of the functions of nondeprived PT Thus ourresults provide further evidence that blind individuals doindeed lsquolsquoseersquorsquo auditory motion

Introduction

Numerous studies show that occipital cortexneurons respond to auditory and tactile stimuli afterearly blindness and these responses are functionallyimportant (for review see L B Lewis amp Fine 2011)Based on these data it has been tempting to speculatethat early blind subjects lsquolsquoseersquorsquo auditory and tactilestimuli However to argue that blind subjects seeauditory or tactile stimuli using the occipital cortex

requires the further demonstration that responseswithin the occipital cortex mediate the perception ofauditory stimuli rather than simply modulating oraugmenting responses within other auditory or tactileareas We chose to examine this question usingauditory motion a stimulus of high ecologicalimportance for blind individuals Specifically usingfMRI pattern classification techniques we testedwhether the perceived direction of motion for bothcoherent and ambiguous auditory motion can becategorized based on neural responses within auditoryareas andor hMTthorn in both normally sighted and earlyblind individuals

A variety of specialized subregions have beenassociated with auditory motion processing in sightedindividuals including the posterior superior temporalsulcus (eg Griffiths et al 1998) the inferior parietallobule (eg Griffiths et al 1997 Krumbholz et al2005) and the planum temporale (eg BaumgartGaschler-Markefski Woldorff Heinze amp Scheich1999 Bremmer et al 2001 J W Lewis Beauchamp ampDeYoe 2000 Warren Zielinski Green Rauscheckeramp Griffiths 2002) The only previous study to examinethe ability to classify the direction of motion of anauditory stimulus based on multivariate blood oxy-genation-level dependent (BOLD) responses (andthereby specifically test for tuning for direction ofmotion) found that decoding was most reliable withinthe planum temporale and a region within right lateraloccipital cortex (aLOC Alink Euler KriegeskorteSinger amp Kohler 2012)

A wide collection of evidence including animal(Newsome Wurtz amp Dursteler 1985) human lesion(Zeki et al 1991) electrophysiological microstimu-lation (Salzman Britten amp Newsome 1990 Salzman

Citation Jiang F Stecker G C amp Fine I (2014) Auditory motion processing after early blindness Journal of Vision 14(13)41ndash18 httpwwwjournalofvisionorgcontent14134 doi10116714134

Journal of Vision (2014) 14(13)4 1ndash18 1httpwwwjournalofvisionorgcontent14134

doi 10 1167 14 13 4 ISSN 1534-7362 2014 ARVOReceived December 30 2013 published November 6 2014

Murasugi Britten amp Newsome 1992 ShadlenBritten Newsome amp Movshon 1996) and BOLDimaging (Huk Dougherty amp Heeger 2002 Tootell etal 1995) implicate hMTthorn (including the middletemporal [MT] area the medial superior temporal[MST] area and possibly additional adjacent motionselective areas Beauchamp Cox amp DeYoe 1997) asplaying an important role in visual motion perceptionIt also has been suggested in a number of fairly recentpapers and reviews that hMTthornmay in fact besupramodal and respond to tactile and auditory aswell as visual motion in sighted subjects (for review seeKupers Pietrini Ricciardi amp Ptito 2011 Renier DeVolder amp Rauschecker 2014) However as describedmore fully in the Discussion many of the papersreporting supramodal responses used stereotaxicgroup averaging to define hMTthorn and may thereforehave included adjacent areas within their definition ofhMTthorn

In early blind individuals a variety of studies havefound responses to auditory motion stimuli within hMTthorn(Bedny Konkle Pelphrey Saxe amp Pascual-Leone 2010Poirier et al 2006 Saenz Lewis Huth Fine amp Koch2008) and multivariate pattern classification analysis hasshown that activations within the hMTthorncomplex in earlyblind participants contain selective information aboutauditory motion (Strnad Peelen Bedny amp Caramazza2013 Wolbers Zahorik amp Giudice 2011) However ithas not yet been clearly established whether suchresponses directly mediate the perception of auditorymotion stimuli or simply modulate or augment re-sponses within other sensory areas

Using an ambiguous auditory motion stimulusallowed us to examine the relationship between neuralsignals and behavioral choice independently of theeffects of stimulus driven responses (Britten NewsomeShadlen Celebrini amp Movshon 1996) Our motivationfor using ambiguous auditory motion is that it ispossible for selective responses to a given feature to bedistributed relatively broadly across the visual systemwhile the conscious experience of that feature may beprimarily based on activity within specialized corticalareas (Kilian-Hutten Valente Vroomen amp Formisano2011 Serences amp Boynton 2007) For example with ananalogous approach to that used here it has beenshown that for unambiguous stimuli the direction ofvisual motion can be classified based on BOLDresponses across much of the visual cortex howeverthe reported perceptual state of the observer forambiguous visual motion stimuli can only be classifiedbased on activity patterns in the human MT complex(Serences amp Boynton 2007) Examining neural re-sponses for ambiguous stimuli therefore allows us toassociate responses within the areas of interest with theperceptual state of the observer

Materials and methods

Auditory classification stimuli

Auditory stimuli were delivered via MRI-compatiblestereo headphones (S14 Sensimetrics Malden MA)and sound amplitude was adjusted to each participantrsquoscomfort level Auditory motion was simulated usingstimuli that contained dynamic interaural time differ-ences (ITD) interaural level differences (ILD) andDoppler shift The stimuli consisted of eight spectrallyand temporally overlapping bands of noise each 1000Hz wide with center frequencies evenly spaced between1500ndash3500 Hz Subjects were presented with the sum ofeight such bands (Figure 1A) Unambiguous stimuli(50 coherence) contained six bands moving to theright and two to the left (or vice versa) Ambiguousstimuli (0 coherence) had four bands moving to theleft and four to the right resulting in no net appliedmotion signal For further details of the stimulus seeSupplementary Materials including SupplementaryFigure S1

Each trial lasted 18 s and contained 6 s of silence and12 s of auditory stimulus presentation The stimulusconsisted of twelve 900-ms auditory motion burstseach separated by a silent interval of 100 ms Inaddition two brief probe beeps occurred roughly 4 sand 10 s after sound onset Participants listened to theauditory stimuli with their eyes closed and were askedto report the apparent direction of motion after eachprobe beep by pressing the corresponding right or leftbutton with their index or middle finger We alternatedthe hand of response between scans so that no specificassociation was developed between rightleft buttonsand indexmiddle fingers For unambiguous motion atrial was counted as correct and considered forsubsequent analysis if the observer correctly identifiedthe global direction of auditory motion and theobserver did not switch his or her answer during thetrial For ambiguous motion a trial was considered forsubsequent analysis if the observer did not switch his orher answer during that trial

Auditory localizer stimuli

Auditory localizer stimuli included coherent motion(100 coherence all bands moving in the samedirection) ambiguous motion (0 coherence fourbands in each direction) static (sound bursts werepresented in the center of the head) and silence Thesefour experimental conditions were repeated in a blockdesign with a fixed order (coherent motion ambiguousmotion static and silence) Participants were asked topassively listen to the auditory stimuli with their eyes

Journal of Vision (2014) 14(13)4 1ndash18 Jiang Stecker amp Fine 2

closed Every participant (both early blind and sighted)performed six scans

Note that our sighted subjects were not blindfoldedduring auditory scans They were asked to have theireyes closed throughout the auditory scans in the darkscanner room A previous study (L B Lewis Saenz ampFine 2010) showed no difference in response in sightedparticipants between blindfolding and eyes-closedconditions across a variety of auditory tasks includingauditory frequency auditory motion and auditoryletter discrimination It is unlikely that the differencebetween blindfolding and eyes closed was critical to thecurrent study

Visual hMTthorn localizer stimuli

To localize hMTthorn in sighted participants we used atraditional hMTthorn localizer stimulus consisting of acircular aperture (radius 88) of moving dots with acentral fixation cross surrounded by a gap (radius 158to minimize motion induced eye movements) in the dotfield Dots were white on a black background and eachsubtended 038 (dot density one per degree) All the dotsmoved coherently in one of eight directions (spacedevenly between 08 and 3608) with a speed of 88s Toprevent the tracking of individual dots dots had limitedlife time (200 ms)

Each block lasted 10 s during which one of the threevisual stimulation conditions (motion static andfixation) was presented In the motion block dotsmoved coherently in one of the eight directions and thedirection of motion changed once per second (the samedirection was prevented from appearing twice in arow) In the static block dots were presented withoutmotion and the positions of the dots were reset onceper second In the fixation condition participants werepresented with only a fixation cross but no dots Thethree conditions were presented in a fixed order(motion static and fixation) Participants were askedto fixate throughout the scan and performed no task

Participants

Participants included seven young sighted (threemales 27 6 32 years old) and seven early blind (EB)adults (four males 50 6 12 years old) with low or nolight perception Demographic data and the causes ofblindness are summarized in Table 1 Note that EB1reported very poor vision even before 5 years old andhas no visual memories We included EB1 because herdata is very typical of the other early blind adults

All participants reported normal hearing and nohistory of psychiatric illness Written and informedconsent was obtained from all participants prior to the

Figure 1 Experimental design (A) Schematic of the auditory motion stimulus The 50 coherence condition is shown Frequency

noise bands were generated by filtering white noise in the Fourier domain (B) Early blind subjects are significantly better at

determining the direction of 50 coherence auditory motion stimulus Error bars show SEM p 0001 Wilcoxon rank sum test

two-tailed


experiment following procedures approved by theUniversity of Washington

MRI scanning

Scanning was performed with a 3T Philips system(Philips Eindhoven The Netherlands) at the Univer-sity of Washington Diagnostic Imaging Sciences Center(DISC) Three-dimensional (3-D) anatomical imageswere acquired at 1 middot 1 middot 1-mm resolution using a T1-weighted magnetization-prepared rapid gradient echo(MPRAGE) sequence BOLD functional scans wereacquired with following common parameters 275 middot275 middot 3-mm voxels flip anglefrac14 768 field of viewfrac14 220middot 220

For the auditory motion localizer experiment weused a sparse block design (repetition time (TR) 10 secho time (TE) 165 ms) Each 10-s block consisted of a8-s stimulus presentation interval containing eightsound bursts (during which there was no scanner noise)followed by a 2-s acquisition period in which 32transverse slices were acquired Each scan lastedapproximately 5 min and included thirty-two 8-sauditory stimulus presentation intervals followed by 32fMRI data acquisitions

Based on pilot data we used a continuous (ratherthan sparse) imaging paradigm (Hall et al 1999) forthe auditory motion classification experiment Arepetition time of 2 s was used to acquire 30 transverseslices (TE 20 ms) Every participant (both early blindand sighted) performed six scans Each scan lastedapproximately 7 min and included 24 trials Theadvantages of sparse scanning techniques are that theylimit the effects of acoustic noise and have higher signalto noise for individual volumes (Hall et al 1999Petkov Kayser Augath amp Logothetis 2009) How-ever many fewer volumes can be acquired (Hall et al1999 Petkov et al 2009) We used a continuoussequence and averaged across four volumes Our pilotdata suggested that the increase in signal-to-noise foreach individual acquisition does not compensate fullyfor the loss in the number of acquisitions and sparse

techniques require an increase in the amount ofscanning time needed as compared to continuousacquisition to obtain comparable signal to noise afteraveraging across acquisitions

A similar continuous block design was used for thehMTthorn localizer experiment A repetition time of 2 swas used to acquire 30 transverse slices (TE 30 ms)Every sighted participant performed two scans Eachscan lasted approximately 5 min and included thirty10-s blocks

Region of interest selection

Regions of interest (ROIs) were defined functionallywithin anatomical constraints Because the number ofvoxels entered into the analysis can potentiallyinfluence peak classification accuracy for every ROIdescribed below we restricted the maximum clusterspread for each subject to 7 mm across all threedimensions (ie x y and z) We chose this max clusterspread range because the resulting voxel number wasclose to the lowest common number of voxels availableacross all functionally defined ROIs (all ps 005uncorrected) This resulted in an average of 25contiguous gray matter voxels per ROI (in functionalvoxel resolution) Wilcoxon rank sum tests did not findsignificant differences in the number of gray mattervoxels across subject groups for any of the ROIs afterBonferroni-Holm correction

hMTthornV5 was defined functionally using a separatevisual (sighted subjects) or auditory (blind subjects)motion localizer For sighted subjects we selectedvoxels near the posterior part of the inferior temporalsulcus that were significantly activated more by movingdots versus static dots Following Bedny et al (2010)and Saenz et al (2008) for blind subjects we selectedvoxels in the same location that were significantlyactivated more by the 100 coherent auditory motionversus silence in the auditory motion localizer We usedauditory motion versus silence because responses toauditory motion versus static did not reliably localizehMTthorn in two individual early blind subjects (EB6 and

Sex Age Blindness onset Cause of blindness Light perception

EB1 F 63 Right eye ruptured 2 months

detached retina 5 years

Detached retina No

EB2 M 59 Born blind Retinopathy of prematurity No

EB3 F 60 15 years Optic nerve virus infection Low

EB4 M 47 Born blind Congenital glaucoma Low

EB5 F 52 Born blind Retinopathy of prematurity No

EB6 M 38 Born blind Congenital glaucoma Low in right eye

EB7 M 31 Born blind Leberrsquos congenital amaurosis No

Table 1 Blind participantsrsquo characteristics


EB7) To verify the location of hMTthorn participantsrsquoanatomical images (AC-PC aligned ACfrac14 anteriorcommissure PCfrac14 posterior commissure) were affine-registered to MNI152 space (MNI frac14Montreal Neuro-logical Institute) using linear image registration tool(FLIRT FSL Jenkinson amp Smith 2001) and theresulting transforms were then applied to functionallydefined hMTthorn These functional hMTthornROIs were thencross-referenced to the Julich probabilistic atlas(Eickhoff et al 2007 Malikovic et al 2007 Wilms etal 2005)

To ensure that our results were not influenced bydifferences in ROI selection across subject groups wealso analyzed our pattern classification data using agroup hMTthorn ROIs created by finding the voxelssignificant for 100 coherent auditory motion versusstatic at group level Using voxel selection criteriasimilar to Strnad et al (2013) for each subject wefound the spherical cluster (radius 2 mm 33 contiguousvoxels) that had the highest average t value for thecontrast 100 coherent auditory motion staticcondition (see Supplementary Materials)

PAC was identified using a combination of ana-tomical and functional criteria Each subjectrsquos Heschlrsquosgyrus was defined as the most anterior transverse gyruson the supratemporal plane following a variety ofprevious studies (Morosan et al 2001 PenhuneZatorre MacDonald amp Evans 1996 RademacherCaviness Steinmetz amp Galaburda 1993 see Saenz ampLangers 2014 for a review) We defined PAC as thecontiguous cluster of voxels in Heschlrsquos gyrus showingthe most significant activation to 100 coherentmotion versus silence using the auditory localizerstimulus

Planum temporale (PT) was defined as the voxels inthe triangular region lying caudal to the Heschlrsquos gyrus

on the supratemporal plane that showed the mostsignificant activation for 100 coherent motion versussilence There was no overlap between hMTthornand PT inany individual subject or using on group definitions ofhMTthorn and PT

To check results were not dependent on ourparticular choice of PT localizer we reanalyzed ourdata using a PT defined in individuals based oncontrast (both-motion [coherent and ambiguous] vsstatic) A similar approach has been used previously byWarren et al (2002) who defined PT based on a similarcontrast (all motion vs stationary see SupplementaryMaterials)

We noticed that at group level the activation of rightPT extended posteriorly into the temporoparietaljunction However we did not find any significantactivation for 100 coherent motion versus silence inthe parietal regions even at a liberal statisticalthreshold (p 005 uncorrected) We were not able todefine any parietal ROIs at an individual level Note wedesigned our experiment with a focus on hMTthorn andPT so our 32 transverse slices did not extend over thefull parietal region and as a consequence did notinclude some of the parietal regions that havepreviously been reported to show responses selectivefor auditory motion (Griffiths et al 1998)

Right LOC was defined based on Talairach coordi-nates (3567 8) as reported by Alink et al (2012)These coordinates were then converted into eachindividualrsquos AC-PC space via an inverse Talairachtransformation (BVQX Toolbox) This ROI has beenpreviously confirmed by Alink et al (2012) to benonoverlapping with the location typically reported forobject-selective LOC (Larsson amp Heeger 2006 Malachet al 1995) as well as the location typically reported forhMTthorn (Dumoulin et al 2000)

We confirmed that right LOC did not substantiallyoverlap with hMTthorn in three ways (a) right LOC andhMTthornROIs did not overlap in any sighted individuals(b) in sighted individuals while the LOC ROI did showsignificant responses to visual moving dots (p 005Wilcoxon signed rank tests) and marginally significantresponses to static dots (p frac14 00781 Wilcoxon signedrank tests) there was not a differential response to thetwo types of stimuli as would be the case if right LOCwas motion selective (Wilcoxon rank sum tests seeSupplementary Figure S2 in Supplementary Materials)and (c) we calculated the percentage overlap betweenthe right LOC ROI and the mean Talairach coordi-nates of the individually defined hMTthorn ROI 62 SD(see Table 2) There was no overlap for early blindsubjects and there was a 4 overlap for sightedsubjects There was no overlap between right LOC andan alternative definition of hMTthorn (see below) for eitherblind or sighted subjects These three measures

M SD

x y z x y z

Sighted control

Right hMTthorn 44 66 1 48 45 50

Left hMTthorn 46 65 0 42 29 50

Right PT 50 29 12 85 44 43

Left PT 49 31 11 55 60 33

Right PAC 46 19 6 55 49 30

Left PAC 42 21 7 58 57 43

Early blind



Right PT 49 28 11 33 55 39

Left PT 50 29 10 54 67 21

Right PAC 48 15 4 24 51 26

Left PAC 49 17 4 53 53 37

Table 2 Talairach coordinates of individually defined ROIs


confirmed that our right LOC ROI was unlikely to be asubdivision of hMTthorn

Data analysis

Data were analyzed using Brain Voyager QX(Version 23 Brain Innovation Maastricht the Neth-erlands) and MATLAB (Mathworks MA) Prior tostatistical analysis functional data underwent prepro-cessing steps that included 3-D motion correctionlinear trend removal and high pass filtering Slice scantime correction was performed for functional dataacquired with continuous sequences but not forfunctional data acquired using sparse sequences Foreach individual participant anatomical and functionaldata were transformed first into his or her own AC-PCspace (rotating the cerebrum into the anterior com-missurendashposterior commissure plane) for ROI-basedclassification

ROI classification

Classification was performed within ROIs defined insubjectsrsquo own AC-PC space Raw time series wereextracted from all voxels within each ROI (eg rightPAC) or each spherical searchlight during a periodextending from 4 to 12 s (four volumes) after the onsetof the auditory stimulus in the auditory motionclassification experiment For each voxel raw timeseries from each trial were averaged across the fourvolumes and then normalized by the mean BOLDresponse of all included trials from the same scan Wethen carried out a hold-one-out jack-knife procedurewhere normalized temporal epochs from both unam-biguous- and ambiguous-motion trials from all but onescan were extracted to form a training dataset for theclassification analysis Normalized temporal epochsfrom both unambiguous and ambiguous-motion trialsfrom the remaining scans were defined as the test setThis was repeated across the six scans for eachparticipant with each scan serving as the test set once

Following OrsquoToole Jiang Abdi and Haxby (2005)we classified each test pattern (right vs left) using lineardiscriminant classifiers after carrying out principalcomponent analysis (LDA thorn PCA) Principal compo-nents analysis was performed on the training set dataand the coordinates of individual training patternprojections on these principal components (PCs) wereused as input to the linear discriminant analyses Theusefulness of individual PCs in discriminating trainingpatterns from different auditory motion direction wasassessed using the signal detection measure d0 A d0

threshold of 025 was used to select PCs to be combinedinto an optimal low-dimensional subspace classifier for

classifying test data set This threshold ensured thatacross all participants the optimal classifier includedapproximately 5ndash10 individual PCs

For each of the four functionally andor anatomicallydefined ROIs the classification procedure was applied tounambiguous- and ambiguous-motion test patternsseparately and the reported classification accuracy wasaveraged across the six scans for each participant andthen averaged separately across sighted and early blindparticipants To measure our ability to classify thereported direction of motion based on the pattern ofresponses within each ROI a subject-level t test wasperformed for each group to test whether classificationaccuracy from this ROI was consistently higher thanchance level (50) across seven participants

Spherical-searchlight classification

In addition to our ROI analysis we also examinedclassification performance using a hypothesis-freespherical-searchlight approach (Kriegeskorte Goebelamp Bandettini 2006) To do this the functional datawere transformed into Talairach space (Talairach ampTournoux 1988) Spherical searchlights were centeredon each single voxel in Talairach space and were sizedto contain the 33 surrounding voxels (2-mm radius)For each searchlight reported classification accuracywas averaged across the six scans and was stored inTalairach space with each searchlight projecting itsaverage accuracy to the position of its center voxelThis analysis resulted in a total of 14 (seven early blindand seven sighted) individual classification accuracymaps aligned in Talairach space

Following (Alink et al 2012) individual classifica-tion accuracy maps were spatially smoothed with aGaussian kernel (3-mm full width at half maximum[FWHM]) A subject-level t test was performed for eachgroup to test which regions of Talairach space showedclassification accuracy consistently higher than chancelevel (50) across the seven participants of each groupA t threshold of 596 was used in conjunction with acluster threshold of four (ie at least four adjacentvoxels needed to exceed the t threshold) correspondingto p 0001 (corrected for multiple comparisons seeFigure S2 for thresholded clusters)

We chose to use a relatively simple classificationprocedure PCAthorn LDA Because our goal was tocompare classification accuracy between blind andsighted individuals an attractive feature of the PCAthornLDC method is that the only model parameter underthe control of the experimenter is the d0 threshold usedto select PCs (see OrsquoToole et al 2007 for a review)The overall classification accuracy of auditory motionthat we achieved using PCAthorn LDA is comparable tothe accuracy achieved in previous studies using similar


stimuli and more powerful classification approachessuch as linear support vector machines (Alink et al2012 Strnad et al 2013)

Results

Behavioral performance

Blind subjects were better at the task In the auditoryclassification experiment a Wilcoxon rank sum testshowed that early blind subjects had significantlysuperior behavioral performance on identifying theapparent direction of unambiguous motion (ie 50coherence) trials (Z frac143721 p 0001 two-tailedFigure 1B)

Localization of hMTthorn

hMTthorn was functionally defined individually forsighted and early blind subjects (see Table 2 for meanTalairach coordinates and their standard deviations)There is a potential concern that the difficulty inherentin defining hMTthorn within early blind subjects mightresult in a systematic bias or inaccuracy of definition inearly blind subjects This was examined in three ways

(a) We cross-registered each individual hMTthornROI toan MNI152 coordinate system Using resampling statis-tics we confirmed that the Euclidian distance betweenthe blind and sighted centroid hMTthorn locations was not

significantly larger than would be expected by chance (p 005 for both left and right hemispheres conserva-tively uncorrected for multiple comparisons) showingthat there was no systematic offset between the estimatedlocation of hMTthorn in blind and sighted subjects

(b) We compared each individualrsquos hMTthornROI withthe Julich probabilistic atlas for hMTthornV5 (Eickhoff etal 2007 Malikovic et al 2007 Wilms et al 2005)This atlas provides the probability value of any voxelbelonging to hMTthorn We extracted the histograms of theprobability values of belonging to the atlas for eachsubjectrsquos functionally defined hMTthornROI and found nostatistical difference in these probability distributionsacross blind and sighted subjects (left hemisphere p frac1403739 right hemisphere pfrac14 09099 two-sampleKolmogorov-Smirnov test N frac14 105)

(c) Finally we redid most of our analyses using analternative definition of hMTthorn (as described inMethods) and obtained similar results These resultsare described in Supplementary MaterialsSupplementary Figures S4 and S5

Thus we do not believe systematic biases in hMTthornROI selection can explain the differences we findbetween blind and sighted subjects

Beta weights within ROIs

Figure 2 shows our ROIs in the right hemisphere in arepresentative early blind (top row) and sighted(bottom row) subject visual motion area hMTthorn (red)PAC (green) PT (blue) and LOC (cyan)

Figure 2 Sagittal views of the four ROIs in the right hemisphere defined using a combination of anatomical and functional criteria are

shown in ACPC space in a representative blind (top row) and sighted (bottom row) subject Red hMTthorn Green PAC Blue PT CyanLOC


Figure 3 shows beta weight responses to 100coherent auditory motion versus silence in the localizerexperiment Because our goal was simply to identifyROIs for further analysis we did not correct formultiple comparisons A Wilcoxon signed rank testfound that early blind subjects showed significantBOLD responses to auditory motion in hMTthorn (p 005 both hemispheres) whereas sighted subjects didnot show a significant BOLD response (p 021 and p 037 for right and left hemisphere respectively) Bothearly blind and sighted subjects showed significantBOLD responses to auditory motion versus silencewithin PAC (p 005 both hemispheres) and PT (p 005 both hemispheres) Sighted subjects showed asmall but significant suppression of response in rightLOC (p 005) whereas in early blind subjects theresponse was significantly positive (p 005)

We carried out separate nonparametric ANOVAs(Wobbrock Findlater Gergle amp Higgins 2011) onbeta weights for each area testing subject group (blindvs sighted) and hemisphere (LH vs RH for bilateralROIs only) In area hMTthorn there was a significant maineffect of group Blind versus Sighted F(1 24)frac146645 p

0001 but no effect of hemisphere (LH vs RH p 098) or significant interaction between group andhemisphere (p 056) In area PAC and PT there wereno significant main effects or interactions (all ps 012) In the right LOC there was a significant effect ofgroup F(1 12) frac14 153 p 001

Group comparisons on beta weights were carried outseparately for each ROI using Wilcoxon rank sumtests In the case of hMTthorn one-tailed tests uncorrectedfor multiple comparisons were used because our initialexperimental prediction was that we would find higheractivation bilaterally to auditory motion within hMTthornin early blind individuals In other bilateral ROIs weused two-tailed tests with Bonferroni-Holm correctionfor the number of hemispheres (Holm 1979) Earlyblind subjects showed significantly higher beta weightsthan sighted subjects within both left and right hMTthorn(p 0001 for both hemispheres) Early blind subjectsalso showed significantly higher beta weights thansighted subjects within right LOC (p 001) There wasno difference in activation across subject groups in PTor PAC (all ps 014)

For results using hMTthorn and PT ROIs defined usingalternative methods see Supplementary Materials

Classification performance within ROIs

We began by examining which ROIs showedclassification performance significantly better thanchance Because our goal was to identify ROIs forfurther analysis we did not correct for multiplecomparisons Figure 4 shows classification perfor-mance for both unambiguous and ambiguous motionIn early blind subjects a one-tailed Wilcoxon sign ranktest found that classification performance within hMTthornwas significantly above chance for unambiguousmotion (50 coherent) in both hemispheres (p 005uncorrected for multiple comparisons) Similarlyclassification performance for ambiguous motion wasabove chance within left hMTthorn (p 005) but notwithin right hMTthorn (p 010) Within early blindsubjects the apparent direction of auditory motioncould not be decoded within either PT (all ps 068) orthe right LOC ROI (p 010)

In contrast within sighted subjects the apparentdirection of motion could not be classified withinhMTthorn for either unambiguous or ambiguous motionin either hemisphere Within the PT ROI classificationperformance for both ambiguous and unambiguousmotion was above chance in the right hemisphere (p

001 both types of motion) but not the left (both ps

010) Within the right LOC ROI classificationperformance was above chance for unambiguous (p

005) but not ambiguous motion (p 010)

Figure 3 Responses to 100 coherent auditory motion in the

auditory motion localizer experiment (A) hMTthorn (B) PAC (C) PTand (D) LOC Error bars show SEM Wilcoxon signed rank tests

(uncorrected for multiple comparisons) were used to examine

whether responses were significantly different from zero

Wilcoxon rank sum tests (PAC PT two-tailed Bonferroni-Holm

corrected for hemisphere right LOC two-tailed uncorrected

hMTthorn one-tailed uncorrected) were used to test for differ-

ences between subject groups p 005 p 001 p

0001


Direction of motion could not be successfully

classified within PAC in either hemisphere for either

subject group Note that our failure to classify auditory

motion direction in PAC is consistent with previousfindings that PAC is not specifically involved in the

perception of sound movement (Griffiths et al 1998

Warren et al 2002) The PAC ROI was therefore

excluded from further statistics and is not shown inFigure 4

We then carried out post hoc nonparametricANOVAs on classification performance testing subjectgroup (blind vs sighted) middot motion coherence level(50 vs 0) middot hemisphere (LH vs RH for bilateralROIs only) for each ROI separately In our hMTthornROIthere was a significant main effect of subject group F(148)frac14 1968 p 00001 with no other significant maineffects or interactions (all ps 023) In our PT ROIthere was once again a significant main effect of subjectgroup F(1 48) frac14 809 p 001 and a significantinteraction between subject group and hemisphere F(148)frac14 691 p 002 reflecting the right hemispherelateralization of PT classification in sighted partici-pants In our right LOC ROI there was no significanteffect of group (p 035) or motion coherence level (p 016) and no interaction between them (p 063)

Group comparisons were carried out on classifica-tion performance separately for each ROI usingWilcoxon rank sum tests In the case of hMTthorn one-tailed tests uncorrected for multiple comparisons wereused because our experimental prediction was that wewould find better classification for blind subjectsbilaterally in hMTthorn In early blind subjects classifica-tion for unambiguous motion was significantly betterthan in sighted subjects in the right hemisphere (p 005) and was not significantly better than in sightedsubjects in the left hemisphere (p 010) Forambiguous motion early blind subjectsrsquo classificationperformance was significantly better than sightedsubjects in the left hemisphere (p 001) and wasmarginally significant in the right hemisphere (pfrac1400641) Further research is needed to confirm whetherthere is possible dissociation between left and righthMTthorn in early blind versus sighted participants as afunction of the motion coherence

In the case of the PT ROI two-tailed tests correctedfor multiple comparisons were used Sighted subjectsshowed significantly better classification that blindsubjects for both unambiguous motion and ambiguousmotion in the right (p 005 both motion coherencelevels) but not the left hemisphere (p 060)

There was no significant difference in classificationperformance between sighted subjects and early blindsubjects within right LOC (p 076 both motioncoherence levels)


Classification performance using a sphericalsearchlight

Our spherical-searchlight analysis revealed addi-tional cortical regions that contained directional

Figure 4 fMRI pattern classification performance Left panels

show classification accuracy for the direction of the unambig-

uous motion stimulus (50 coherence) right panels show

classification accuracy for the direction of ambiguous motion

stimulus (0 coherence) (AndashB) hMTthorn (CndashD) PT and (EndashF) LOC

Error bars show SEM Wilcoxon signed rank tests (uncorrected

for multiple comparisons) were used to examine whether

classification performance was significantly above chance




ences between subject groups p 005 p 001


information for auditory motion (p 0001 correctedfor multiple comparisons see Supplementary Figure S3in Supplementary Materials) In sighted subjects weidentified one region located in the right superiortemporal gyrus (Talairach coordinates xfrac14 43 yfrac1450zfrac14 13) that contained directional information forunambiguous motion (mean classification performance53 SEM 0004) An additional region in the rightmiddle occipital gyrus was selective for ambiguousmotion in sighted subjects (Talairach coordinates x frac1434 yfrac1478 zfrac14 12 mean classification performance53 SEMfrac14 0004) Note that this region is lateral andsuperior to the region of the right middle occipitalgyrus (BA19 x frac14 51 yfrac1464 zfrac145) that haspreviously been shown to show a preference for soundlocalization in early blind subjects (Renier et al 2010)

In early blind subjects two areas were identified assuccessfully classifying ambiguous motion includingone in the left fusiform gyrus (Talairach coordinates xfrac1442 yfrac1454 zfrac1412 mean classificationperformance 52 SEMfrac14 0007) and one in the rightparahippocampal gyrus (Talairach coordinates xfrac14 28yfrac1428 zfrac1421 mean classification performance 52SEMfrac14 0002)

Effects of age

There was a substantial difference in mean agebetween our early blind and control subjects (50 vs 27years) and it is well established that performance formany types auditory processing deteriorates as afunction of age (for review see Tun Williams Small ampHafter 2012) Thus it is possible that our behavioralresults underestimate the behavioral superiority ofearly blind individuals

Our fMRI results cannot easily be explained by agedifferences between subject groups We saw nosignificant correlation between age and performancefor either BOLD or pattern classification performancethat passed Bonferroni-Holm correction for eithersubject group In particular (a) we saw no indication ofa negative correlation between pattern classificationperformance and age in either LOC or PT Indeedcorrelations were nonsignificantly positive across bothareas and subject groups Thus our failure to classifydirection of motion in these areas within blind subjectsis unlikely to be due to their being older (b) The onlycorrelations that were significant before Bonferroni-Holm correction were a negative correlation betweenBOLD responses and age in hMTthorn in sightedindividuals (r frac14061 p frac14 002) and a positivecorrelation between BOLD responses and age in hMTthornin blind individuals (rfrac14 064 p frac14 001) Thus ourresults in hMTthorn are unlikely to be due to performancein this area improving with age Nevertheless we

acknowledge that there was substantial age differencebetween groups

Discussion

Superior motion processing in early blindindividuals

There is a wide range of previous studies suggesting(though not uniformly Fisher 1964 L A Renier etal 2010) improved spatial localization for staticauditory stimuli in blind subjects (Juurmaa amp Suonio1975 Muchnik Efrati Nemeth Malin amp Hilde-sheimer 1991 Rice Feinstein amp Schusterman 1965Roder et al 1999) also see Rauschecker (1995) for areview of the animal literature There is also evidencethat blind subjects have lower minimum audiblemovement angles using a single moving sound source(Lewald 2013) Here we show that blind subjectsshowed significantly better behavioral performancethan sighted subjects at determining the direction ofauditory motion using a relatively naturalistic stimulusconsisting of a number of sound sources that includedILD ITD and Doppler cues Our stimulus wasdesigned to be analogous to the visual global motionstimuli varying in coherence that have classically beenused to evoke responses in MT and MST (BrittenShadlen Newsome amp Movshon 1992) These stimuliare designed to minimize the ability of subjects to trackthe local movement over time of individual dots orsound sources (as can be done when a single soundsource or visual dot is used as a stimulus) and therebymaximize reliance on global motion mechanisms

hMTthorn and PT

Using fMRI pattern classification in sighted indi-viduals the perceived direction of motion for bothcoherent and ambiguous auditory motion stimuli wasaccurately categorized based on neural responseswithin right PT Sighted subjects did not showsignificant modulation of the BOLD response toauditory motion within hMTthorn and direction ofauditory motion could not be classified from responsesin that region

Within early blind individuals hMTthorn responded toauditory motion and auditory motion decisions couldbe successfully categorized Surprisingly in blindsubjects the ability to classify direction of auditorymotion within PT was significantly worse than forsighted subjects

Thus our results are suggestive of a doubledissociation whereby in early blind subjects classifica-


tion for auditory motion direction is enhanced withinvisual area hMTthorn and reduced within PT compared tosighted subjects

Right LOC

In sighted subjects LOC showed robustly positiveresponses to both moving and static visual dots with nosignificant difference in response between them(Supplementary Figure S2) weak or no motionselectivity Right LOC showed a small but significantsuppression of response to the auditory motionstimulus (Figure 3) However despite a lack of positiveresponse to auditory motion the direction of motioncould be decoded from responses in right LOC Thisfinding is generally consistent with Alink et al (2012)who found successful multivariate classification ofdirection of auditory motion in right LOC without anysignificant overall (univariate) modulation of response

In contrast within early blind subjects we see largerresponses to auditory motion than to silence but thedirection of motion could not be decoded from thoseresponses It should be noted that our finding of agroup difference in classification is still somewhatprovisional An ANOVA did reveal a significant effectof group within right LOC whereby sighted subjectsshowed better classification than blind subjects How-ever individual posthoc tests did not show a significantdifference across groups

The effects of blindness on right LOC is difficult tointerpret without a better understanding of the role ofthis region in sighted subjects This ROI is nonover-lapping with the object-selective LOC (Larsson ampHeeger 2006 Malach et al 1995) and regionsassociated with 3-D processing (Amedi JacobsonHendler Malach amp Zohary 2002 Brouwer van Ee ampSchwarzbach 2005 Georgieva Peeters Kolster Toddamp Orban 2009 Orban Sunaert Todd Van Hecke ampMarchal 1999) Moreover currently it is unclear towhat extent this particular region of LOC is supra-modal in sighted subjects and whether it supportsclassification of visual as well as auditory motiondirection

Lack of successful classification in PAC

Although neurons sensitive to cues for auditorymotion have been found within PAC in both cats andmonkeys (Ahissar Ahissar Bergman amp Vaadia 1992Stumpf Toronchuk amp Cynader 1992 ToronchukStumpf amp Cynader 1992) a wide variety of previousgroups have shown that PAC does not differentiate inthe magnitude of the BOLD response between movingand stationary stimuli (for review see Warren et al

2002) There are a number of ways in which neuronsselective for auditory motion might exist within PACwithout eliciting robust univariate BOLD responses formoving vs stationary stimuli For example tuningpreferences might be distributed relatively evenly acrossmoving and stationary stimuli excitatory and inhibi-tory responses might be fairly evenly balanced ortuning might be extremely broad All of these would belikely to minimize an overall difference in BOLDresponse to moving versus stationary stimuli withinPAC

We could not classify the direction of motion of ourauditory motion stimulus within PAC However ourresults should not be taken as evidence againstsensitivity to local auditory motion cues in PAC giventhat we used a complex stimulus that minimized theability to track local sound sources Our findings doprovided limited evidence for either a lack of globalmotion selectivity in PAC or a difference in its spatialorganization andor hemodynamic connectivity (An-derson amp Oates 2010) compared to neighboring PTwhere classification was successful in sighted subjects

Is hMTthorn supramodal in sighted individuals

In the data shown here in sighted subjects we saw nosignificant modulation of the BOLD response toauditory motion within each subjectrsquos hMTthorn (ifanything there was a slight suppression of hMTthornresponses when subjects listened to auditory motion)and direction of auditory motion could not beclassified As far as the previous literature on auditorymotion is concerned two studies have reportedauditory responses within hMTthorn within normallysighted subjects Poirier et al (2005) reported largerBOLD responses to auditory motion (vs static) stimuliin blindfolded sighted subjects using a definition ofhMTthorn based on group averaging in stereotaxiccoordinates This group also reported the position ofclusters that showed significant activation to movingversus static auditory stimuli While these clusters werereported as being in the expected anatomical locationof hMTthorn only two of the eight reported coordinates ofindividual clusters fall within 2 SDs of the expectedlocation of hMTthorn across individuals as reported byDumoulin et al (2000 also see Watson et al 1993)Using multivoxel pattern analysis Strnad et al (2013)recently showed that while the overall BOLD responseto auditory motion was negative (in contrast to Poirieret al 2005 but similar to L Lewis Saenz amp Fine2007) a region defined as hMTthorn did contain classifi-cation information about different auditory motionconditions in sighted individuals However in thispaper hMTthorn was defined as all voxels within arelatively generous 10 mm radius from MNI group


peak coordinates The size of the ROIs was thenreduced by a feature-selection criterion including onlythe 50 (out of 1000 voxels in the ROI) based on thehighest t values from the contrast task rest Thus thisanalysis is likely to be highly susceptible to theinclusion of voxels from neighboring areas

In contrast a variety of studies that have not reliedon stereotaxic alignment to define hMTthorn have failed tofind evidence of auditory motion responses in hMTthornIndeed the issue of to what extent auditory responseswithin hMTthorn are an artifact of alignment wasspecifically examined by Saenz et al (2008) who foundthat group averaged methods (surface space alignmentrather than stereotaxic alignment) resulted in theappearance of auditory responses within hMTthorn insighted subjects However inspection of that same datausing individual hMTthornROIs (based on individualvisual functional localizers) demonstrated that the vastmajority of individually defined hMTthorn ROIs did notrespond to auditory motion and that these responseswere in fact primarily located in a neighboring regionThus in that study the finding of BOLD responses toauditory motion within a group average hMTthorn waslargely attributable to intersubject averaging Thisfinding was replicated in a very similar study on thesame subjects by L B Lewis et al (2010)

Similarly Alink et al (2012) who defined ROIsbased on individual anatomies found no response toauditory motion and could not classify the direction ofauditory motion within hMTthorn Like us they did findauditory motion responses within neighboring LOCBedny et al (2010) who projected a conservativelydefined group defined ROI onto individual anatomiessimilarly did not see auditory motion responses inhMTthorn in sighted or late blind subjects J W Lewis etal (2000) who aligned data on the cortical surface in astudy specifically designed to examine overlap betweenvisual and auditory motion processing found negativeBOLD responses in occipital cortex including subre-gions of hMTthorn but did see positive BOLD responses tothe auditory motion stimulus in neighboring superiortemporal sulcus (STS)

Like others (J W Lewis et al 2000 Strnad et al2013) we see some indication of suppressive modula-tion of hMTthorn when subjects perform an auditorymotion task It remains to be seen whether thismodulation is due to cross-modal attention (Ciarami-taro Buracas amp Boynton 2007) and whether it isselective for motion

The failure to find auditory responses in hMTthorn insighted individuals is somewhat surprising given thesubstantial literature reporting tactile responses (egHagen et al 2002 Matteau Kupers RicciardiPietrini amp Ptito 2010 Proulx Brown Pasqualotto ampMeijer 2014 Ricciardi et al 2007) selective for thedirection of tactile motion (van Kemenade et al 2014)

in hMTthorn within sighted subjects as well as disruptionof tactile processing with inhibition induced byrepetitive transcranial magnetic stimuluation (rTMS)over the expected site of hMTthorn (Ricciardi et al 2011)

One possibility is that the tasks and stimuli used tolook for auditory responses in hMTthorn have not beenideal for eliciting such responses Failures to findauditory responses in hMTthorn are necessarily negativeevidence Moreover although the studies that havefailed to find auditory responses in hMTthornwere carriedout in four different laboratories all used relativelysimilar auditory stimuli and tasks (similar to ours orless complex) It is possible that more complexnaturalistic auditory motion stimuli (or some othervariation of task design) would be successful in elicitingauditory motion responses in hMTthorn A secondpossibility is that hMTthorn is less multisensory than theprevailing literature suggests Although as cited abovetactile responses have been reported in hMTthorn across awide range of studies many of these studies localizedhMTthorn using stereotaxic coordinates which may haveresulted in the contribution of tactile motion responsesfrom neighboring polysensory areas (BeauchampYasar Kishan amp Ro 2007) Results from studies thatused individual visual localizers to localize hMTthornsuggest that tactile responses may be primarily limitedto a subregion of MST (Beauchamp et al 2007Ricciardi et al 2007 van Kemenade et al 2014)Moreover since none of these studies controlled forvisual attention the contribution of visualized orimplied motion (eg hMTthorn responds to static picturesof moving objects Kourtzi amp Kanwisher 2000) totactile responses in hMTthorn is not yet fully understoodFinally it is possible that hMTthorn is multimodal fortactile but not auditory stimuli

Although our findings clearly show a differencebetween blind and sighted individuals how oneinterprets our data is influenced by whether or nothMTthorn is eventually shown to have auditory responsesin sighted individuals If auditory motion responseswithin hMTthorn are shown to exist in adult sightedsubjects then the responses we see in blind individualslikely provide an example of cross-modal plasticity inblind subjects mediated by an enhancement or un-masking of responses within a naturally multisensoryarea (see Kupers amp Ptito 2014 for a recent reviewPascual-Leone Amedi Fregni amp Merabet 2005 alsoPascual-Leone amp Hamilton 2001) However if hMTthornproves not to respond to auditory motion in adultsighted subjects our data provides evidence that cross-modal plasticity can involve a categorical change ofadult input modality (Hunt et al 2005 Kahn ampKrubitzer 2002 Karlen Kahn amp Krubitzer 2006)possibly as a result of a failure of normal pruning indevelopment (for reviews see Huberman Feller amp


Chapman 2008 Innocenti amp Price 2005 Katz ampShatz 1996 OrsquoLeary 1992)

In blind individuals auditory hMTthorn responsesare associated with the perceptual experienceof auditory motion

Our results provide an important link between theperceptual experience of auditory motion and re-sponses within hMTthornwithin early blind individuals Avariety of studies of visual motion in sighted subjectshave shown that a wide number of visual areas notthought to be associated with visual motion perceptionnonetheless contain direction-specific information forunambiguous motion stimuli (Kamitani amp Tong 2006Serences amp Boynton 2007) However the reportedperceptual state of the observer for ambiguous visualmotion stimuli can only be classified based on activitypatterns in the human MT complex and possibly V3a(Serences amp Boynton 2007) We show here that hMTthorncan classify the perceptual experience for ambiguousauditory motion stimuli in early blind subjectstherefore showing that responses within this area arenot only correlated with the physical auditory motionstimulus but also with the perceptual experience ofauditory motion in early blind individuals

hMTthorn seems to replace rather than augmentprocessing within PT

These data provide further support for the sugges-tion that the multimodal responses of hMTthorn incongenitally blind individuals are not driven byconnections from the PT (Bedny et al 2010) since wesaw a reduction of the ability to successfully decodeauditory motion direction within that area in earlyblind subjects Indeed for our task hMTthorn appears tosupplant rather than augment motion selective re-sponses within PT In the case of area PT blindsubjects showed similarly robust BOLD modulations to100 auditory motion versus silence as were found insighted subjects but this area no longer classifieddirection of motion successfully suggesting a loss ofauditory directional tuning in this area

One potential source of these bilateral hMTthornresponses might be feedback from parietal or prefrontalareas A variety of polysensory or supramodal areasthat show functional responses to a combination ofauditory and visual motion or spatial position havebeen identified including (but not restricted to) theinferior parietal lobule (Bushara et al 1999 LewaldStaedtgen Sparing amp Meister 2011 J W Lewis et al2000) lateral frontal cortex including the precentralsulcus (J W Lewis et al 2000) and the superior

temporal sulcus (Baumgart et al 1999 BeauchampArgall Bodurka Duyn amp Martin 2004 GriffithsBench amp Frackowiak 1994 J W Lewis et al 2000)In particular in sighted subjects the parietal lobuleshows functional responses to both auditory and visualmotionspatial position information (Bushara et al1999 Lewald et al 2011 J W Lewis et al 2000) andcorrelations between inferior parietal activation andoccipital regions are enhanced as a result of blindness(Weeks et al 2000) Similarly the lateral prefrontalcortex which contains polysensory areas in sightedsubjects (J W Lewis et al 2000) has previously beenshown to have enhanced functional connectivity withhMTthornas a result of early blindness (Bedny et al 2010)

Summary

These data suggest that the plasticity resulting fromearly visual deprivation extends to nondeprived (audi-tory) regions of cortex One model of developmentalspecialization is that organization is determined by acompetition between modules whereby computationaltasks are more likely to be assigned to those brainregions whose innate characteristics are better suited tothat task (Jacobs 1997 Jacobs amp Kosslyn 1994)Consistent with this model it has been suggested thatmany sensory areas may be multisensory at birth andbecome increasingly unimodal through axonal anddendritic refinements that are at least partially deter-mined by competitive refinements during development(for reviews see Huberman et al 2008 Innocenti ampPrice 2005 Katz amp Shatz 1996 OrsquoLeary 1992) It hasalso been suggested that the apparent differences ingray matter thickness as measured using T1 imagingobserved in early blind individuals (Anurova RenierDe Volder Carlson amp Rauschecker in press BridgeCowey Ragge amp Watkins 2009 Jiang et al 2009Park et al 2009 Voss Lepore Gougoux amp Zatorre2011) represent differential pruning as a result of lackof visual experience

This competitive model is also consistent withprevious studies in early blind individuals that havesuggested that the reorganization of function resultingfrom loss of sensory input may be modulated byaspects of computational fitness such as similarity tothe original computational function of that areamdashatheory that has been described as lsquolsquofunctional con-stancyrsquorsquo or lsquolsquometamodal plasticityrsquorsquo in the literature(Amedi et al 2007 Mahon Anzellotti SchwarzbachZampini amp Caramazza 2009 Saenz et al 2008)mdashandor connectivity to other areas such as motor systems(Mahon et al 2007) Thus our findings provide furthersupport for the idea that the exquisite specialization ofhMTthorn for motion processing may generalize to theprocessing of auditory motion presumably because the


processing of auditory motion shares computationalsimilarities to the processing of visual motion

Finally the finding of a reduced capacity forauditory motion direction classification in PT withinblind individuals for our task suggests that in theabsence of visual motion input hMTthornmay actually becapable of usurping some of the functions of non-deprived auditory motion areas Interestingly Sadatoet al (1998) have reported a result for Braille readingthat is highly analogousmdashventral occipital regionsincluding the primary visual cortex and fusiform gyribilaterally were activated in blind Braille readers butsecondary somatosensory areas were less activated byBraille reading in blind individuals than sightedcontrols

lsquolsquoYou guys can see with your eyes we see with ourearsrsquorsquo (Juan Ruiz PopTech 2011) This paper providesfurther evidence that the enhanced auditory motionperformance of early blind individuals may be at leastin part because they lsquolsquoseersquorsquo auditory motion

Keywords blindness cross-modal motion visualdeprivation

Acknowledgments

This work was supported by the National Institutesof Health (EY-014645 to Ione Fine) Fang Jiang wassupported by the Human Frontier Science ProgramLong-Term Fellowship (LT001032008) the AuditoryNeuroscience Training Program (T32DC005361) andthe Pathway to Independence Award (K99EY023268)

Commercial relationships noneCorresponding author Fang JiangEmail fjianguwedu fjianguwashingtoneduAddress Department of Psychology University ofWashington Seattle WA USA

References

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Alink A Euler F Kriegeskorte N Singer W ampKohler A (2012) Auditory motion directionencoding in auditory cortex and high-level visualcortex Human Brain Mapping 33(4) 969ndash978

Amedi A Jacobson G Hendler T Malach R amp

Zohary E (2002) Convergence of visual andtactile shape processing in the human lateraloccipital complex Cerebral Cortex 12(11) 1202ndash1212

Amedi A Stern W M Camprodon J A Berm-pohl F Merabet L Rotman S Hemond C Pascual-Leone A (2007) Shape conveyed byvisual-to-auditory sensory substitution activates thelateral occipital complex Nature Neuroscience10(6) 687ndash689

Anderson M L amp Oates T (2010) A critique ofmulti-voxel pattern analysis In S Ohlsson amp RCatrambone (Eds) Proceedings of the 32nd AnnualMeeting of the Cognitive Science Society (pp 1511ndash1516) Portland OR

Anurova I Renier L A De Volder A G CarlsonS amp Rauschecker J P (in press) Relationshipbetween cortical thickness and functional activa-tion in the early blind Cerebral Cortex

Baumgart F Gaschler-Markefski B Woldorff MG Heinze H J amp Scheich H (1999) Amovement-sensitive area in auditory cortex Na-ture 400(6746) 724ndash726

Beauchamp M S Argall B D Bodurka J Duyn JH amp Martin A (2004) Unraveling multisensoryintegration Patchy organization within human STSmultisensory cortex Nature Neuroscience 7(11)1190ndash1192

Beauchamp M S Cox R W amp DeYoe E A (1997)Graded effects of spatial and featural attention onhuman area MT and associated motion processingareas Journal of Neurophysiology 78(1) 516ndash520

Beauchamp M S Yasar N E Kishan N amp Ro T(2007) Human MST but not MT responds totactile stimulation Journal of Neuroscience 27(31)8261ndash8267

Bedny M Konkle T Pelphrey K Saxe R ampPascual-Leone A (2010) Sensitive period for amultimodal response in human visual motion areaMTMST Current Biology 20(21) 1900ndash1906

Bremmer F Schlack A Shah N J Zafiris OKubischik M Hoffmann K et al (2001)Polymodal motion processing in posterior parietaland premotor cortex A human fMRI studystrongly implies equivalencies between humans andmonkeys Neuron 29(1) 287ndash296

Bridge H Cowey A Ragge N amp Watkins K(2009) Imaging studies in congenital anophthalmiareveal preservation of brain architecture in lsquovisualrsquocortex Brain 132(Pt 12) 3467ndash3480

Britten K H Newsome W T Shadlen M NCelebrini S amp Movshon J A (1996) A


relationship between behavioral choice and thevisual responses of neurons in macaque MT VisualNeuroscience 13(1) 87ndash100

Britten K H Shadlen M N Newsome W T ampMovshon J A (1992) The analysis of visualmotion A comparison of neuronal and psycho-physical performance Journal of Neuroscience12(12) 4745ndash4765

Brouwer G J van Ee R amp Schwarzbach J (2005)Activation in visual cortex correlates with theawareness of stereoscopic depth Journal of Neu-roscience 25(45) 10403ndash10413

Bushara K O Weeks R A Ishii K Catalan M JTian B Rauschecker J P et al (1999)Modality-specific frontal and parietal areas forauditory and visual spatial localization in humansNature Neuroscience 2(8) 759ndash766

Ciaramitaro V M Buracas G T amp Boynton G M(2007) Spatial and cross-modal attention alterresponses to unattended sensory information inearly visual and auditory human cortex Journal ofNeurophysiology 98(4) 2399ndash2413

Dumoulin S O Bittar R G Kabani N J BakerC L Jr Le Goualher G Bruce Pike G et al(2000) A new anatomical landmark for reliableidentification of human area V5MT A quantita-tive analysis of sulcal patterning Cerebral Cortex10(5) 454ndash463

Eickhoff S B Paus T Caspers S Grosbras M-HEvans A C Zilles K et al (2007) Assignment offunctional activations to probabilistic cytoarchi-tectonic areas revisited NeuroImage 36(3) 511ndash521

Fisher G H (1964) Spatial localization by the blindAmerican Journal of Psychology 77 2ndash14

Georgieva S Peeters R Kolster H Todd J T ampOrban G A (2009) The processing of three-dimensional shape from disparity in the humanbrain Journal of Neuroscience 29(3) 727ndash742

Griffiths T D Bench C J amp Frackowiak R S(1994) Human cortical areas selectively activatedby apparent sound movement Current Biology4(10) 892ndash895

Griffiths T D Rees G Rees A Green G GWitton C Rowe D et al (1998) Right parietalcortex is involved in the perception of soundmovement in humans Nature Neuroscience 1(1)74ndash79

Griffiths T D Rees A Witton C Cross P MShakir R A amp Green G G (1997) Spatial andtemporal auditory processing deficits following

right hemisphere infarction A psychophysicalstudy Brain 120(Pt5) 785ndash794

Hagen M C Franzen O McGlone F Essick GDancer C amp Pardo J V (2002) Tactile motionactivates the human middle temporalV5 (MTV5)complex European Journal of Neuroscience 16(5)957ndash964

Hall D A Haggard M P Akeroyd M A PalmerA R Summerfield A Q Elliott M R et al(1999) lsquolsquoSparsersquorsquo temporal sampling in auditoryfMRI Human Brain Mapping 7(3) 213ndash223

Holm S (1979) A simple sequentially rejectivemultiple test procedure Scandinavian Journal ofStatistics 6 65ndash70

Huberman A D Feller M B amp Chapman B(2008) Mechanisms underlying development ofvisual maps and receptive fields Annual Review ofNeuroscience 31 479ndash509

Huk A C Dougherty R F amp Heeger D J (2002)Retinotopy and functional subdivision of humanareas MT and MST Journal of Neuroscience22(16) 7195ndash7205

Hunt D L King B Kahn D M Yamoah E NShull G E amp Krubitzer L (2005) Aberrantretinal projections in congenitally deaf mice Howare phenotypic characteristics specified in develop-ment and evolution The Anatomical Record PartA Discoveries in Molecular Cellular and Evolu-tionary Biology 287(1) 1051ndash1066

Innocenti G M amp Price D J (2005) Exuberance inthe development of cortical networks NatureReviews Neuroscience 6(12) 955ndash965

Jacobs R A (1997) Nature nurture and thedevelopment of functional specializations A com-putational approach Psychonomic Bulletin amp Re-view 4(3) 299ndash309

Jacobs R A amp Kosslyn S M (1994) Encodingshape and spatial relations The role of receptivefield size in coordination complementary represen-tations Cognitive Science 18(3) 361ndash368

Jenkinson M amp Smith S (2001) A global optimisa-tion method for robust affine registration of brainimages Medical Image Analysis 5(2) 143ndash156

Jiang J Zhu W Shi F Liu Y Li J Qin W et al(2009) Thick visual cortex in the early blindJournal of Neuroscience 29(7) 2205ndash2211

Juurmaa J amp Suonio K (1975) The role of auditionand motion in the spatial orientation of the blindand the sighted Scandanavian Journal of Psychol-ogy 16(3) 209ndash216

Kahn D M amp Krubitzer L (2002) Massive cross-modal cortical plasticity and the emergence of a


new cortical area in developmentally blind mam-mals Proceedings of the National Acadamy ofSciences USA 99(17) 11429ndash11434

Kamitani Y amp Tong F (2006) Decoding seen andattended motion directions from activity in thehuman visual cortex Current Biology 16(11)1092ndash1102

Karlen S J Kahn D M amp Krubitzer L (2006)Early blindness results in abnormal corticocorticaland thalamocortical connections Neuroscience142(3) 843ndash858

Katz L C amp Shatz C J (1996) Synaptic activity andthe construction of cortical circuits Science274(5290) 1133ndash1138

Kilian-Hutten N Valente G Vroomen J ampFormisano E (2011) Auditory cortex encodes theperceptual interpretation of ambiguous soundJournal of Neuroscience 31(5) 1715ndash1720

Kourtzi Z amp Kanwisher N (2000) Activation inhuman MTMST by static images with impliedmotion Journal of Cognitive Neuroscience 12(1)48ndash55

Kriegeskorte N Goebel R amp Bandettini P (2006)Information-based functional brain mapping Pro-ceedings of the National Academy of Sciences USA103 3863ndash3868

Krumbholz K Schonwiesner M Rubsamen RZilles K Fink G R amp von Cramon D Y(2005) Hierarchical processing of sound locationand motion in the human brainstem and planumtemporale European Journal of Neuroscience 21(1)230ndash238

Kupers R Pietrini P Ricciardi E amp Ptito M(2011) The nature of consciousness in the visuallydeprived brain Frontiers in Psychology 2 19

Kupers R amp Ptito M (2014) Compensatoryplasticity and cross-modal reorganization followingearly visual deprivation Neuroscience amp Biobeha-vioral Reviews 41 36ndash52

Larsson J amp Heeger D J (2006) Two retinotopicvisual areas in human lateral occipital cortexJournal of Neuroscience 26(51) 13128ndash13142

Lewald J (2013) Exceptional ability of blind humansto hear sound motion Implications for theemergence of auditory space Neuropsychologia51(1) 181ndash186

Lewald J Staedtgen M Sparing R amp Meister I G(2011) Processing of auditory motion in inferiorparietal lobule Evidence from transcranial mag-netic stimulation Neuropsychologia 49 209ndash215

Lewis J W Beauchamp M S amp DeYoe E A(2000) A comparison of visual and auditory

motion processing in human cerebral cortexCerebral Cortex 10(9) 873ndash888

Lewis L Saenz M amp Fine I (2007) Patterns ofcross-modal plasticity in the visual cortex of earlyblind human subjects across a variety of tasks andinput modalities Journal of Vision 7(9) 875 httpwwwjournalofvisionorgcontent79875 doi10116779875 [Abstract]

Lewis L B amp Fine I (2011) The effects of visualdeprivation after infancy In L A Levin S F ENilsson J Ver Hoeve S Wu P L Kaufman amp AAlbert (Eds) Adlerrsquos physiology of the eye Expertconsult (11th ed) St Louis MO Saunders

Lewis L B Saenz M amp Fine I (2010) Mechanismsof cross-modal plasticity in early-blind subjectsJournal of Neurophysiology 104(6) 2995ndash3008

Mahon B Z Anzellotti S Schwarzbach J ZampiniM amp Caramazza A (2009) Category-specificorganization in the human brain does not requirevisual experience Neuron 63(3) 397ndash405

Mahon B Z Milleville S C Negri G A RumiatiR I Caramazza A amp Martin A (2007) Action-related properties shape object representations inthe ventral stream Neuron 55(3) 507ndash520

Malach R Reppas J B Benson R R Kwong KK Jiang H Kennedy W A et al (1995)Object-related activity revealed by functional mag-netic resonance imaging in human occipital cortexProceedings of the National Academy of SciencesUSA 92(18) 8135ndash8139

Malikovic A Amunts K Schleicher A MohlbergH Eickhoff S B Wilms M et al (2007)Cytoarchitectonic analysis of the human extrastri-ate cortex in the region of V5MT1 A probabilisticstereotaxic map of area hOc5 Cerebral Cortex 17562ndash574

Matteau I Kupers R Ricciardi E Pietrini P ampPtito M (2010) Beyond visual aural and hapticmovement perception hMTthorn is activated byelectrotactile motion stimulation of the tongue insighted and in congenitally blind individuals BrainResearch Bulletin 82(5ndash6) 264ndash270

Morosan P Rademacher J Schleicher A AmuntsK Schormann T amp Zilles K (2001) Humanprimary auditory cortex Cytoarchitectonic subdi-visions and mapping into a spatial reference systemNeuroImage 13(4) 684ndash701

Muchnik C Efrati M Nemeth E Malin M ampHildesheimer M (1991) Central auditory skills inblind and sighted subjects Scandanavian Audiology20(1) 19ndash23

Newsome W T Wurtz R H amp Dursteler M R


(1985) Deficits in visual motion processing fol-lowing ibotenic acid lesions of the middle temporalvisual area of the macaque monkey Journal ofNeuroscience 5(3) 825ndash840

OrsquoLeary D D (1992) Development of connectionaldiversity and specificity in the mammalian brain bythe pruning of collateral projections CurrentOpinions in Neurobiology 2(1) 70ndash77

OrsquoToole A J Jiang F Abdi H amp Haxby J V(2005) Partially distributed representations ofobjects and faces in ventral temporal cortexJournal of Cognitive Neuroscience 17(4) 580ndash590

OrsquoToole A J Jiang F Abdi H Penard NDunlop J P amp Parent M A (2007) Theoreticalstatistical and practical perspectives on pattern-based classification approaches to the analysis offunctional neuroimaging data Journal of CognitiveNeuroscience 19(11) 1735ndash1752

Orban G A Sunaert S Todd J T Van Hecke Pamp Marchal G (1999) Human cortical regionsinvolved in extracting depth from motion Neuron24(4) 929ndash940

Park H J Lee J D Kim E Y Park B Oh M KLee S et al (2009) Morphological alterations inthe congenital blind based on the analysis ofcortical thickness and surface area NeuroImage47(1) 98ndash106

Pascual-Leone A Amedi A Fregni F amp MerabetL B (2005) The plastic human brain cortexAnnual Review of Neuroscience 28 377ndash401

Pascual-Leone A amp Hamilton R (2001) Themetamodal organization of the brain In CCasanova amp M Ptito (Eds) Progress in brainresearch Vol 134 (pp 427ndash445) San Diego CAElsevier Science

Penhune V B Zatorre R J MacDonald J D ampEvans A C (1996) Interhemispheric anatomicaldifferences in human primary auditory cortexProbabilistic mapping and volume measurementfrom magnetic resonance scans Cerebral Cortex6(5) 661ndash672

Petkov C I Kayser C Augath M amp Logothetis NK (2009) Optimizing the imaging of the monkeyauditory cortex Sparse vs continuous fMRIMagnetic Resonance Imaging 27(8) 1065ndash1073

Poirier C Collignon O Devolder A G Renier LVanlierde A Tranduy D et al (2005) Specificactivation of the V5 brain area by auditory motionprocessing An fMRI study Brain ResearchCognitive Brain Research 25(3) 650ndash658

Poirier C Collignon O Scheiber C Renier LVanlierde A Tranduy D et al (2006) Auditory

motion perception activates visual motion areas inearly blind subjects NeuroImage 31(1) 279ndash285

Proulx M J Brown D J Pasqualotto A amp MeijerP (2014) Multisensory perceptual learning andsensory substitution Neuroscience amp BiobehavioralReview 41 16ndash25

Rademacher J Caviness V S Jr Steinmetz H ampGalaburda A M (1993) Topographical variationof the human primary cortices Implications forneuroimaging brain mapping and neurobiologyCerebral Cortex 3(4) 313ndash329

Rauschecker J P (1995) Compensatory plasticity andsensory substitution in the cerebral cortex Trendsin Neuroscience 18(1) 36ndash43

Renier L De Volder A G amp Rauschecker J P(2014) Cortical plasticity and preserved function inearly blindness Neuroscience amp BiobehavioralReview 41 53ndash63

Renier L A Anurova I De Volder A G CarlsonS VanMeter J amp Rauschecker J P (2010)Preserved functional specialization for spatialprocessing in the middle occipital gyrus of the earlyblind Neuron 68(1) 138ndash148

Ricciardi E Basso D Sani L Bonino D VecchiT Pietrini P et al (2011) Functional inhibitionof the human middle temporal cortex affects non-visual motion perception A repetitive transcranialmagnetic stimulation study during tactile speeddiscrimination Experimental Biology and Medicine236(2) 138ndash144

Ricciardi E Vanello N Sani L Gentili CScilingo E P Landini L et al (2007) The effectof visual experience on the development of func-tional architecture in hMTthorn Cerebral Cortex17(12) 2933ndash2939

Rice C E Feinstein S H amp Schusterman R J(1965) Echo-detection ability of the blind Size anddistance factors Journal of Experimental Psychol-ogy 70 246ndash255

Roder B Teder-Salejarvi W Sterr A Rosler FHillyard S A amp Neville H J (1999) Improvedauditory spatial tuning in blind humans Nature400(6740) 162ndash166

Sadato N Pascual-Leone A Grafman J DeiberM P Ibanez V amp Hallett M (1998) Neuralnetworks for Braille reading by the blind Brain121(Pt 7) 1213ndash1229

Saenz M amp Langers D R (2014) Tonotopicmapping of human auditory cortex HearingResearch 307 42ndash52

Saenz M Lewis L B Huth A G Fine I amp KochC (2008) Visual motion area MTthornV5 responds to


auditory motion in human sight-recovery subjectsJournal of Neuroscience 28(20) 5141ndash5148

Salzman C D Britten K H amp Newsome W T(1990) Cortical microstimulation influences per-ceptual judgements of motion direction Nature346(6280) 174ndash177

Salzman C D Murasugi C M Britten K H ampNewsome W T (1992) Microstimulation in visualarea MT Effects on direction discriminationperformance Journal of Neuroscience 12(6) 2331ndash2355

Serences J T amp Boynton G M (2007) Therepresentation of behavioral choice for motion inhuman visual cortex Journal of Neuroscience27(47) 12893ndash12899

Shadlen M N Britten K H Newsome W T ampMovshon J A (1996) A computational analysis ofthe relationship between neuronal and behavioralresponses to visual motion Journal of Neurosci-ence 16(4) 1486ndash1510

Strnad L Peelen M V Bedny M amp Caramazza A(2013) Multivoxel pattern analysis reveals auditorymotion information in MTthorn of both congenitallyblind and sighted individuals PLoS ONE 8(4)e63198

Stumpf E Toronchuk J M amp Cynader M S(1992) Neurons in cat primary auditory cortexsensitive to correlates of auditory motion in three-dimensional space Experimental Brain Research88(1) 158ndash168

Talairach J amp Tournoux P (1988) Co-planarstereotaxic atlas of the human brain New YorkThieme Medical Publishers

Tootell R B Reppas J B Dale A M Look R BSereno M I Malach R et al (1995) Visualmotion aftereffect in human cortical area MTrevealed by functional magnetic resonance imagingNature 375(6527) 139ndash141

Toronchuk J M Stumpf E amp Cynader M S(1992) Auditory cortex neurons sensitive to corre-lates of auditory motion Underlying mechanismsExperimental Brain Research 88(1) 169ndash180

Tun P A Williams V A Small B J amp Hafter ER (2012) The effects of aging on auditory

processing and cognition American Journal ofAudiology 21(2) 344ndash350

van Kemenade B M Seymour K Wacker ESpitzer B Blankenburg F amp Sterzer P (2014)Tactile and visual motion direction processing inhMTthornV5 NeuroImage 84 420ndash427

Voss P Lepore F Gougoux F amp Zatorre R J(2011) Relevance of spectral cues for auditoryspatial processing in the occipital cortex of theblind Frontiers in Psychology 2 48

Watson J D Myers R Frackowiak R S Hajnal JV Woods R P Mazziotta J C et al (1993)Area V5 of the human brain Evidence from acombined study using positron emission tomogra-phy and magnetic resonance imaging CerebralCortex 3(2) 79ndash94

Warren J D Zielinski B A Green G GRauschecker J P amp Griffiths T D (2002)Perception of sound-source motion by the humanbrain Neuron 34(1) 139ndash148

Weeks R A Horwitz B Aziz-Sultan A Tian BWessinger C M Cohen L et al (2000) Apositron emission tomographic study of auditorylocalisation in the congenitally blind Journal ofNeuroscience 20 2664ndash2672

Wilms M Eickhoff S B Spech K Amunts KShah N J Malikovic A et al (2005) HumanV5MTthorn Comparison of functional and cytoar-chitectonic data Anatomy and Embryology 210485ndash495

Wobbrock J O Findlater L Gergle D amp HigginsJ J (2011) The aligned rank transform fornonparametric factorial analyses using only AN-OVA procedures Paper presented at the Proceed-ings of the ACM Conference on Human Factors inComputing Systems (CHI 2011) Vancouver BritishColumbia

Wolbers T Zahorik P amp Giudice N A (2011)Decoding the direction of auditory motion in blindhumans NeuroImage 56(2) 681ndash687

Zeki S Watson J D Lueck C J Friston K JKennard C amp Frackowiak R S (1991) A directdemonstration of functional specialization in hu-man visual cortex Journal of Neuroscience 11(3)641ndash649


Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1

Murasugi Britten amp Newsome 1992 ShadlenBritten Newsome amp Movshon 1996) and BOLDimaging (Huk Dougherty amp Heeger 2002 Tootell etal 1995) implicate hMTthorn (including the middletemporal [MT] area the medial superior temporal[MST] area and possibly additional adjacent motionselective areas Beauchamp Cox amp DeYoe 1997) asplaying an important role in visual motion perceptionIt also has been suggested in a number of fairly recentpapers and reviews that hMTthornmay in fact besupramodal and respond to tactile and auditory aswell as visual motion in sighted subjects (for review seeKupers Pietrini Ricciardi amp Ptito 2011 Renier DeVolder amp Rauschecker 2014) However as describedmore fully in the Discussion many of the papersreporting supramodal responses used stereotaxicgroup averaging to define hMTthorn and may thereforehave included adjacent areas within their definition ofhMTthorn

In early blind individuals a variety of studies havefound responses to auditory motion stimuli within hMTthorn(Bedny Konkle Pelphrey Saxe amp Pascual-Leone 2010Poirier et al 2006 Saenz Lewis Huth Fine amp Koch2008) and multivariate pattern classification analysis hasshown that activations within the hMTthorncomplex in earlyblind participants contain selective information aboutauditory motion (Strnad Peelen Bedny amp Caramazza2013 Wolbers Zahorik amp Giudice 2011) However ithas not yet been clearly established whether suchresponses directly mediate the perception of auditorymotion stimuli or simply modulate or augment re-sponses within other sensory areas

Using an ambiguous auditory motion stimulusallowed us to examine the relationship between neuralsignals and behavioral choice independently of theeffects of stimulus driven responses (Britten NewsomeShadlen Celebrini amp Movshon 1996) Our motivationfor using ambiguous auditory motion is that it ispossible for selective responses to a given feature to bedistributed relatively broadly across the visual systemwhile the conscious experience of that feature may beprimarily based on activity within specialized corticalareas (Kilian-Hutten Valente Vroomen amp Formisano2011 Serences amp Boynton 2007) For example with ananalogous approach to that used here it has beenshown that for unambiguous stimuli the direction ofvisual motion can be classified based on BOLDresponses across much of the visual cortex howeverthe reported perceptual state of the observer forambiguous visual motion stimuli can only be classifiedbased on activity patterns in the human MT complex(Serences amp Boynton 2007) Examining neural re-sponses for ambiguous stimuli therefore allows us toassociate responses within the areas of interest with theperceptual state of the observer


Auditory classification stimuli

Auditory stimuli were delivered via MRI-compatiblestereo headphones (S14 Sensimetrics Malden MA)and sound amplitude was adjusted to each participantrsquoscomfort level Auditory motion was simulated usingstimuli that contained dynamic interaural time differ-ences (ITD) interaural level differences (ILD) andDoppler shift The stimuli consisted of eight spectrallyand temporally overlapping bands of noise each 1000Hz wide with center frequencies evenly spaced between1500ndash3500 Hz Subjects were presented with the sum ofeight such bands (Figure 1A) Unambiguous stimuli(50 coherence) contained six bands moving to theright and two to the left (or vice versa) Ambiguousstimuli (0 coherence) had four bands moving to theleft and four to the right resulting in no net appliedmotion signal For further details of the stimulus seeSupplementary Materials including SupplementaryFigure S1

Each trial lasted 18 s and contained 6 s of silence and12 s of auditory stimulus presentation The stimulusconsisted of twelve 900-ms auditory motion burstseach separated by a silent interval of 100 ms Inaddition two brief probe beeps occurred roughly 4 sand 10 s after sound onset Participants listened to theauditory stimuli with their eyes closed and were askedto report the apparent direction of motion after eachprobe beep by pressing the corresponding right or leftbutton with their index or middle finger We alternatedthe hand of response between scans so that no specificassociation was developed between rightleft buttonsand indexmiddle fingers For unambiguous motion atrial was counted as correct and considered forsubsequent analysis if the observer correctly identifiedthe global direction of auditory motion and theobserver did not switch his or her answer during thetrial For ambiguous motion a trial was considered forsubsequent analysis if the observer did not switch his orher answer during that trial

Auditory localizer stimuli

Auditory localizer stimuli included coherent motion(100 coherence all bands moving in the samedirection) ambiguous motion (0 coherence fourbands in each direction) static (sound bursts werepresented in the center of the head) and silence Thesefour experimental conditions were repeated in a blockdesign with a fixed order (coherent motion ambiguousmotion static and silence) Participants were asked topassively listen to the auditory stimuli with their eyes







Participants






two-tailed



MRI scanning












Detached retina No


















M SD

x y z x y z

Sighted control



Right PT 50 29 12 85 44 43

Left PT 49 31 11 55 60 33

Right PAC 46 19 6 55 49 30

Left PAC 42 21 7 58 57 43

Early blind



Right PT 49 28 11 33 55 39

Left PT 50 29 10 54 67 21

Right PAC 48 15 4 24 51 26

Left PAC 49 17 4 53 53 37




Data analysis


ROI classification












Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1






Participants






two-tailed



MRI scanning












Detached retina No


















M SD

x y z x y z

Sighted control



Right PT 50 29 12 85 44 43

Left PT 49 31 11 55 60 33

Right PAC 46 19 6 55 49 30

Left PAC 42 21 7 58 57 43

Early blind



Right PT 49 28 11 33 55 39

Left PT 50 29 10 54 67 21

Right PAC 48 15 4 24 51 26

Left PAC 49 17 4 53 53 37




Data analysis


ROI classification












Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1


MRI scanning












Detached retina No


















M SD

x y z x y z

Sighted control



Right PT 50 29 12 85 44 43

Left PT 49 31 11 55 60 33

Right PAC 46 19 6 55 49 30

Left PAC 42 21 7 58 57 43

Early blind



Right PT 49 28 11 33 55 39

Left PT 50 29 10 54 67 21

Right PAC 48 15 4 24 51 26

Left PAC 49 17 4 53 53 37




Data analysis


ROI classification












Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1










M SD

x y z x y z

Sighted control



Right PT 50 29 12 85 44 43

Left PT 49 31 11 55 60 33

Right PAC 46 19 6 55 49 30

Left PAC 42 21 7 58 57 43

Early blind



Right PT 49 28 11 33 55 39

Left PT 50 29 10 54 67 21

Right PAC 48 15 4 24 51 26

Left PAC 49 17 4 53 53 37




Data analysis


ROI classification












Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1


Data analysis


ROI classification












Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1


Results


































0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1




















0001































Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1






























Effects of age




Discussion



hMTthorn and PT






Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1


Right LOC



























Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1

















Summary








Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1





Acknowledgments



References























































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1







































































































Introduction


f01

t01

t02

Results

f02

f03

f04

Discussion

Ahissar1

Alink1

Amedi1

Amedi2

Anderson1

Anurova1

Baumgart1

Beauchamp1

Beauchamp2

Beauchamp3

Bedny1

Bremmer1

Bridge1

Britten1

Britten2

Brouwer1

Bushara1

Ciaramitaro1

Dumoulin1

Eickhoff1

Fisher1

Georgieva1

Griffiths1

Griffiths2

Griffiths3

Hagen1

Hall1

Holm1

Huberman1

Huk1

Hunt1

Innocenti1

Jacobs1

Jacobs2

Jenkinson1

Jiang1

Juurmaa1

Kahn1

Kamitani1

Karlen1

Katz1

KilianHutten1

Kourtzi1

Kriegeskorte1

Krumbholz1

Kupers1

Kupers2

Larsson1

Lewald1

Lewald2

Lewis1

Lewis2

Lewis3

Lewis4

Mahon1

Mahon2

Malach1

Malikovic1

Matteau1

Morosan1

Muchnik1

Newsome1

OLeary1

OToole1

OToole2

Orban1

Park1

PascualLeone1

PascualLeone2

Penhune1

Petkov1

Poirier1

Poirier2

Proulx1

Rademacher1

Rauschecker1

Renier1

Renier2

Ricciardi1

Ricciardi2

Rice1

Roder1

Sadato1

Saenz1

Saenz2

Salzman1

Salzman2

Serences1

Shadlen1

Strnad1

Stumpf1

Talairach1

Tootell1

Toronchuk1

Tun1

vanKemenade1

Voss1

Watson1

Warren1

Weeks1

Wilms1

Wobbrock1

Wolbers1

Zeki1

Auditory motion processing after early blindness · 2016. 2. 28. · 2013; Wolbers, Zahorik, &...

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Transcript of Auditory motion processing after early blindness · 2016. 2. 28. · 2013; Wolbers, Zahorik, &...