The MfERG and Cone Isolating Stimuli

882019 The MfERG and Cone Isolating Stimuli

httpslidepdfcomreaderfullthe-mferg-and-cone-isolating-stimuli 115

Journal of Vision (2002) 2 543-558 httpjournalofvisionorg282 543

The multifocal electroretinogram (mfERG) and coneisolating stimuli Variation in L- and M-cone drivensignals across the retina

Johannes AlbrechtDivision of Experimental Ophthalmology University Eye

Hospital Tuumlbingen Germany

Herbert JaumlgleDivision of Experimental Ophthalmology University Eye

Hospital Tuumlbingen Germany

Donald C HoodDepartment of Psychology

Columbia University New York NY USA

Lindsay T SharpeDepartment of Experimental Psychology University of

Newcastle Newcastle-upon-Tyne UK

Multifocal electroretinograms (mfERG) were recorded from 38 normal trichromats with a pattern-reversing display thatmodulated only their long-wavelength sensitive (L) or only their middle-wavelength sensitive (M) cones at equal conecontrasts and average quantal catches The display consisted of scaled 103 hexagonal elements subtending 84deg x 75degof visual angle Typically the amplitude of the L-cone driven signal was greater than that for the M-cone driven one at allretinal eccentricities but large differences were found among observers These values correlated with L- to M-cone ratiosobtained psychophysically in the same observers using 2deg (dia) heterochromatic flicker photometry Interestingly the L- toM-cone driven amplitude ratios differed between the central and peripheral retina For the central fovea (5deg dia) the meanratio was 14 plusmn 06 (for the N1P1 component) whereas for the annular ring centered at 40deg in the periphery it was 23 plusmn

20 The mean P1 latency of the summed M-cone driven mfERG (280 plusmn 26 ms) was significantly advanced relative to theL-cone driven signal (290 plusmn 19 ms) but the mean N1 latencies were similar (156 plusmn 17 ms and 162 plusmn 13 msrespectively) The P1 latency difference between the L- and M-cone driven waveforms was not found in the central 5deg(dia) of the retina However it increased with retinal eccentricity The regional differences in the amplitudes and latencies

of the L- and M-cone driven mfERG signals can be related to variations in the L- to M-cone ratios andor the receptor tobipolar gain factors that depend on eccentricity

Keywords color vision cones retinal cone mosaic electroretinography (ERG) multifocal electroretinography (mfERG)

IntroductionRecently we have used a cone silent substitution

technique based on the Stockman and Sharpe (2000) cone fundamentals to modulate only the long-wavelengthsensitive (L) or only the middle-wavelength sensitive (M)cones in the human multifocal electroretinogram(mfERG) These procedures allow us to quantify topographical variations in the integrity of L- and M-conedriven mfERG signals in clinical patients Here we exploitthe cone isolating mfERG to obtain information abouttopographical variation in the processing of L- and M-cone driven signals across the retina in normal observers

Current molecular genetic models of L- and M-conephotopigment gene expression are consistent with greaterL- than M-cone photopigment gene expression ( NathansThomas amp Hogness 1986 for a review see SharpeStockman Jaumlgle Knau amp Nathans 1999 ) This greater L-than M-cone photopigment expression was originally

inferred from both psychophysical andelectrophysiological studies involving techniques asdiverse as heterochromatic flicker photometry (HFP) ( De

Vries 1946 1948 Kremers et al 2000 ) psychophysicaldetection thresholds ( Cicerone amp Nerger 1989 VimalPokorny Smith amp Shevell 1989 Pokorny Smith amp

Wesner 1991 Wesner Pokorny Shevell amp Smith1991 ) Ganzfeld flicker electroretinography ( Carroll

McMahon Neitz amp Neitz 2000 Kremers et al 2000 )retinal densitometry ( Kremers et al 2000 ) and highresolution optical imaging ( Roorda amp Williams 1999 )The L- to M-cone ratios derived from such studies rangefrom 031 to 871 depending on target location andsize However these procedures provide either small local(usually central foveal) or large-field retinal estimates By contrast molecular biological analysis of opsin mRNA assayed from postmortem human eyes has providedtopographical estimates ( Hagstrom Neitz amp Neitz 1997 1998 ) which suggest a central L- to M-cone ratio of 151

DOI 101167282 Received July 30 2001 published November 25 2002 ISSN 1534-7362 copy 2002 A



Albrecht Jaumlgle Hood amp Sharpe

with an increase to 301 in the mid-periphery (circa 41degeccentricity) But the resolution obtained with thistechnique so far does not allow conclusions to be madeconcerning the cone ratio in the central 10deg

The cone isolating mfERG offers advantages thatnicely compensate for the resolution and regionallimitations inherent to the psychophysical ERG and

mRNA studies With the mfERG technique it is possibleto isolate L- and M-cone driven signals with a resolution of about 5deg (dia) of visual angle over a large visual area (84deg x 75deg) However the straightforward interpretation of mfERG amplitudes with regard to L- and M-conedistributions is complicated by the complexity of themfERG waveform It consists of two initial majorcomponents which are analogues of the a- and b-waves of the full-field flash ERG ( Hood Seiple Holopigian ampGreenstein 1997 ) an initial negative deflection (N1)followed by a positive peak (P1) In addition there is asecond prominent negative deflection (N2) present as well

Chemical isolation of components of both the full-

field and mfERG of monkeys has established that the N1component is largely an OFF-bipolar response withrelatively small contributions from the inner retina andthe cone photoreceptors ( Sieving Murayama ampNaarendorp 1994 Horiguchi Suzuki Kondo Tanikawaamp Miyake 1998 Hare et al 2001 Hood 2000 HoodFrishman Saszik amp Viswanathan 2002a ) In contrastthe P1 component is predominantly produced by theonset of the ON-bipolar cells and to some extent by theoffset of the OFF-bipolars and the N2 component islargely produced by the offset of both the ON-bipolarsand OFF-bipolars ( Hood et al 2002a ) Obviously any attempt to relate the ratio of L- to M-cone driven mfERGsto L- to M-cone photoreceptor mosaic ratios requires acomprehensive model of how these distal neuralcomponents alter the waveform Nevertheless asimplified model assuming a close relation between L-and M-cone driven mfERG amplitudes and L- to M-coneratios may be justified under limited conditions

Here we present evidence to establish such a relationincluding (1) comparisons of the L- and M-cone isolatingresponse waveforms (2) their amplitude versus intensity responses at five levels (3) their contrast responses at twolevels and (4) correlations between the mfERG L- to M-cone estimates and estimates obtained in the same groupof observers using a psychophysical HFP technique Theevidence analysed topographically is roughly consistent

with the simplified model although the model holds less well for the peripheral retina (gt 5deg of visual angle) than itdoes for the central fovea (lt 5deg) Additionally the dataprovide insight into how regional differences in theamplitudes and latencies of the L- and M-cone drivenmfERG signals can be related to variations in the L- to M-cone ratios and in gain factors in the outer retina Finallythis work serves as a basis for interpreting evidenceobtained from L- and M-cone isolating multifocal visually evoked potentials (mfVEPs) relying on the same cone

isolating procedures that are presented in anaccompanying study ( Hood et al 2002b )

MethodsSubjects

Thirty-eight trichromats 25 males and 13 females(aged 19 to 51 years) participated in our study All hadnormal (corrected) visual acuity and were classified ascolor normal on the basis of their performance onstandard color vision tests including the Ishiharapseudoisochromatic plates and the Nagel Type Ianomaloscope One of the normal trichromat females(JB) is a heterozygotic carrier for protanopia asestablished by the family pedigree (the maternalgrandfather is a protanope) and by preliminary moleculargenetic analysis In addition 4 protanopes (aged 21 to 33

years) and 5 deuteranopes (aged 22 to 38 years) weretested The classification of protanopia and deuteranopia

was based on Rayleigh red-green equation matches madeon the Nagel Type I anomaloscope (Schmidt amp HaenschBerlin Germany) The genotypes of the dichromats weredetermined by molecular genetic (DNA) analysis of

venous blood samples There was no evidence of afunctional M-cone opsin gene in the deuteranopes or of afunctional L-cone opsin gene in the protanopes In allsubjects one or both eyes were maximally dilated (circa 8mm) by application of a mydriatic (05 tropicamide)and kept light-adapted before and during the mfERGrecording Corneal mfERG responses were measured witha DTL fiber electrode The reference and ground skinelectrodes were attached to ipsilateral temple and the

forehead respectively Informed consent was obtainedfrom all subjects after explanation of the purpose andpossible consequences of the study This study wasconducted in accordance with the tenets of theDeclaration of Helsinki and with the approval of theInstitutional Ethics Committee in HumanExperimentation at the University of Tuumlbingen

Visual Stimulation and mfERGRecording

The stimulus was generated on a flat-screen SONY Trinitron monitor with a resolution of 1024 x 768 pixelsIt consisted of 103 hexagonal elements (see Figure 1 )

which subtended 84deg x 75deg of visual angle at a viewingdistance of 18 cm Each element was alternated in colorpseudorandomly between two values carefully selected tomodulate activity in a single cone class The mfERGstimulation and data collection and analysis wereperformed by VERIS system software (Version 301)from EDI [see Sutter (1991) and Sutter amp Tran (1992) formore details] The appropriate colors or cone isolatingstimuli were calculated from the emission spectra of thethree phosphors and the Stockman and Sharpe cone




fundamentals determined for 10deg and larger viewingconditions ( Stockman amp Sharpe 1998 1999 2000 )

The emission spectra of the red green and bluephosphors of the monitor were measured with a compactarray spectroradiometer (CAS 140 Instrument SystemsMuumlnchen Germany) The calibration of the monitor wasperformed under the same conditions as the experiments

The red phosphor had its primary peak at 627 nm (fullbandwidth at half-maximum [FBHM] = 4 nm) and asecondary peak at 707 nm (FBHM = 6 nm) the energy of

which was 60 of that of the primary peak The greenphosphor had its peak at 522 nm (FBHM = 80 nm) andthe blue at 453 nm (FBHM = 63 nm) The maximumintensities of the red green and blue phosphors were 24793 and 138 cdm 2 respectively Linearity testsestablished that the emission spectra of the threephosphors did not significantly change for the variousluminance levels used during stimulation

The modulation of cone excitation was quantified by the cone contrast formula

100 x ( E max ndash E min )( E max + E min ) (1)

where E max and E min are respectively the maximal andminimal cone excitations For our phosphor conditionsit was possible to obtain a maximum cone contrast of 47 for either the L- or the M-cone isolating stimuli

while maintaining the contrast of the remaining long- wavelength cone type (ie either L- or M-cones) and theS-cones at 0 The rod system contribution to themfERG was suppressed by the bright rapidly alternatingstimulus and by maintaining the ambient roomluminance falling on the monitor screen at 150 cdm 2

The mean luminances of the L- and M-cone isolatingstimuli were 192 cdm 2 and 338 cdm 2 respectivelycorresponding to average quantal catches of approximately 446 log quanta s-1

cone -1 for the L-conesunder the L-cone modulating condition and 443 logquanta s-1

cone -1 for the M-cones under the M-conemodulating condition (for details about the conversionssee Pugh 1988 and Wyszecki amp Stiles 1982 ) Nearly identical cone contrast and average cone quantal catchesfor the L- and M-cones were chosen to ensure that bothcone classes were stimulated at the same adapting leveland to allow direct comparisons between the amplitudesand latencies of their mfERG signals

The continuous mfERG recordings were amplified by 200 k with the low and high frequency set at 10 and 100Hz for half amplitude (Grass Instruments) and weresampled at 1200 Hz The frame rate was 75 Hz and thepseudo random m-sequence had 2 14-1 elementscorresponding to a total recording time of 3 min and 385s for each condition In total 16383 patterns werepresented in which each of the 103 hexagons changedpseudorandomly between two colors To improve thesubjectrsquos ability to maintain fixation the experimentalruns were broken up into 16 overlapping segments each

lasting 1365 s The L- and M-cone isolating recordingsfor each subject were obtained in a single session (withrandom assignment of order) under identical electrodeplacement and amplification conditions to make theresults comparable

25deg

37deg

12deg

58deg

73deg

80deg

6

54

21

3

Figure 1 Schematic representation of the 103 independenthexagons employed in the mfERG paradigm The numbersindicate the six concentric rings used to analyse the summedsignals Note that the size of the hexagons changes fromcenter to periphery to compensate for the variation in conedensity with retinal eccentricity and to ensure that thehexagons produce multifocal ERG responses of approximatelyequal amplitude ( Sutter amp Tran 1992 )

ResultsDichromat Data

To establish the reliability of the silent substitutionmethod we recorded the mfERG responses to the L- andM-cone modulation stimuli in color-blind observers wholack either the function of the L- (protanopes) or M-(deuteranopes) cones Figure 2 displays their mfERGresponses summed over all 103 hexagons for the eyetested As expected the summed mfERG responses to L-cone modulation ( Figure 2A ) were absent or below the

noise level in the four protanopes and those to M-conemodulation ( Figure 2D ) were absent or below the noiselevel in the five deuteranopes In contrast the mfERGresponses to pure modulation of the remaining M- or L-cone class were robust ( Figure 2B and 2C ) The absenceof any signal for pure M-cone modulation in thedeuteranopes ( Figure 2D ) is reassuring for it additionally establishes that under our photopic conditions the rodsare not contributing to the mfERGs It is important toprevent rod intrusion especially for the M-cone isolating




stimulus because of the similarity of the rod spectralsensitivity to that of the M-cones

L-conemodulation

M-conemodulation

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

D e u

t e r a n o p e

P r o

t a n o p e

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

C D

Figure 2 The mfERG responses (summed from all 103hexagons and normalized) obtained from four protanopes (A ampB) and five deuteranopes (C amp D) for the L- (left column) andM- (right column) cone isolating stimuli The inset at the bottomof the panels indicates the scale

Intensity Response SeriesTo validate that the relative amplitudes of the L- and

M-cone driven signals do not change with luminancelevel we measured intensity response series from 38 to192 cdm 2 for the L-cone driven signals and from 68 to338 cdm 2 for the M-cone driven signals at a constantcone contrast of 47 Figure 3 summarizes the resultsobtained for observer AY (OD) a subject with nearly equal L- and M-cone driven responses (see Table 1 ) Thetraces have been summed for the L- (A red curves) andM- (B green curves) cone isolating conditions and thenfurther analysed in terms of amplitude (C) and latency (D) as a function of luminance for both the N1 andN1P1 (the difference between the N1 minimum and theP1 maximum see Figure 3 for the definitions of N1 andP1) (All latencies here and in subsequent figures aremeasured from the beginning of the trace to the peak of the component of interest) Clearly with increasingluminance for both the L- and M-cone driven signals theamplitude of both components increases in magnitude ata similar rate and there is a corresponding reduction inlatency Thus there is no significant change in the ratio of

the L- to M-cone driven amplitudes of the mfERG overthe range of luminances tested

Intensity ()20 40 60 80 100

L a

t e n c y

( m s

)

10

15

20

25

30

35

A m p

l i t u d e

( n v d e g

2 )

0

2

4L-cone driven N1P1M-cone driven N1P1L-cone driven N1M-cone driven N1

Intensity ()20 40 60 80 100

C D

L-cone modulation

05 nVdeg 2

0 20 40 60 80 ms

158 -06291 1680

174 -04291 1660

183 -06307 1040

241 -04307 0420

Latencies ValuesnVdeg 2ms

158 -10291 18100

I n t e n s i t y

( )

A B

05 nVdeg 2

0 20 40 60 80 ms

166 -08282 14

166 -08307 10

191 -06315 08

208 -04307 06

80

60

40

20

100 158 -10266 16

Latencies ValuesnVdegms

M-cone modulation

P1

N1

Figure 3 Intensity response series for the mfERG responses of one subject (AY) with nearly equal L- and M-cone drivenresponses obtained under the L- (Panel A red curves) and M-(Panel B green curves) cone isolating conditions The intensitywas increased from 38 to 192 cdm 2 for the L-cones and from68 to 338 cdm 2 for the M-cones at a constant cone contrast

of 47 The individual focal responses have been summedwithin the entire field depicted in Figure1 The latencies andamplitude values given at the right of the traces correspond tothe two cursor positions (filled square) Panels C and D depictamplitude and latency responses as a function of increasingluminance for both the N1 and P1 components of the mfERGsummed over the full field N1 and P1 are labeled on the upper left trace

Contrast Response SeriesTo establish that the relative amplitudes of the L- and

M-cone driven signals are independent of contrast level we measured the signals at two different contrasts 27and 47 The luminance was held constant at 192cdm 2 for the L-cones and 338 cdm 2 for the M-conesFigure 4 summarizes the results obtained for twoobservers for whom the responses from both eyes areshown MK (see Table 1 ) who has an L-cone drivenamplitude (red curves) which is a factor 24 greater thanher M-cone driven amplitude (green curves) and EL

who has more nearly equal L- and M-cone drivenresponses (factor 14) For the two observers thecalculated L- to M-cone driven ratios averaged over both




eyes are very similar at both contrasts 237 plusmn 014 (MK)and 137 plusmn 014 (EL) for 27 contrast and 235 plusmn 007(MK) and 125 plusmn 007 (EL) for 47 contrast Thus

within the range of values tested the L- and M-conedriven amplitudes appear to be linear with contrast withthe M- and L-cone driven responses both increasing onaverage by a factor of 15 for MK and 16 for EL going

from 27 to 47 contrast

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

L-conemodulation

M-conemodulation

EL

MK

47

27

47

27

Figure 4 The L- (A red curves) and M- (B green curves) conedriven mfERG signals measured for two subjects under twocontrast conditions 47 (our standard condition) and 27 (alower contrast condition) EL is a subject with nearly equal L-and M-cone driven responses MK has an L-cone drivenamplitude that is a factor 24 greater than her M-cone drivenamplitude (see Table 1 ) The individual focal responses havebeen summed over the entire field depicted in Figure1 and theresults have been averaged for the left (upper trace) and right(lower trace) eyes

Full Field L- and M-Cone DrivenAmplitudes

The data obtained for the maximum contrast level(47) are summarized in Tables 1 and 2 These tableslist the amplitudes and latencies of the N1 and P1components of the mfERG responses summed over all

103 hexagons for each of the 38 observers (Note thelatencies are given for P1 but the amplitudes are givenfor N1P1 the difference between the minimum of thefirst negative peak [N1] and the maximum of the firstpositive peak [P1]) In 23 of the 38 subjects (10 femalesand 13 males) mfERGs were simultaneously recordedfrom both eyes

The amplitude data ( Table 1 ) indicate that the L-conedriven N1 and N1P1 signals are typically larger than theM-cone driven ones the large inter-individual variability

in amplitude notwithstanding Averaged over all subjectsthe mean L-cone driven signal amplitudes for the N1 andN1P1 components are 062 plusmn 030 nVdeg 2 and 165 plusmn 079 nVdeg 2 respectively whereas the mean M-conedriven signal amplitudes for the N1and N1P1components are 045 plusmn 021 nVdeg 2 and 094 plusmn 050nVdeg 2

Binocular ComparisonsThe difference in amplitude between the L- and M-

cone driven signals does not depend on which eye isrecorded as the same relation is found in the two eyes of those 23 observers from whom the mfERGs weresimultaneously recorded On average the N1 L- to M-cone driven signal ratio of each eye in each subjectdeviates by 152 plusmn 111 from the average of both theireyes and the N1P1 L- to M-cone driven signal ratiodeviates by only 90 plusmn 92 (The slightly larger deviationin the N1 signals is presumably related to the smallersignal which is more influenced by noise) Whenseparately analysed by gender the deviation between eyesis slightly smaller in the 13 males (N1 = 146 plusmn 120N1P1 = 83 plusmn 90) than in the 10 females (N1 161 plusmn 90 P1 105 plusmn 98) A larger variance between the twoeyes might be expected in females owing to local

variations in the distributions of L- and M-conephotoreceptors (and hence in the cone driven signals)arising from X-chromosome inactivation (see Sharpe etal 1999 for a review)

Full-Field and Ring Analysed L- andM-Cone Driven Waveforms

The difference in amplitude between the mean L-and M-cone driven signals is highlighted in Figure 5

which depicts the mean waveforms of the L- and M-conedriven signals of the full-field summed (lowest traces)and ring analysed (traces numbered according to theannuli depicted in Figure 1 ) mfERGs averaged over all38 subjects Figure 5A shows the unadjusted mean L-(red curves) and M- (green curves) cone drivenresponses In Figure 5B the M-cone driven responses

were normalized to the N1P1 peak of the L-cone drivenone For the central element (trace 1) the appropriatescaling factor is 14 for the five peripheral rings (traces 2

to 6) it is a constant value of 22 the same value asfound for the full-field summed response (unnumberedlowest trace) which is dominated by the peripheralinput Although the scaled waveforms are very similar inshape there are some important differences in therelative sizes of their N1 to N1P1 peaks (the two cannotbe brought into perfect symmetry) and their N1 and P1latencies differ as well




Table 1 The N1 and N1P1 Amplitudes of the L- and M-Cone Driven mfERGs in 38 Trichromats

Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22

Mean plusmn SD 062 plusmn 030 045 plusmn 021 165 plusmn 112 165 plusmn 079 094 plusmn 050 219 plusmn 143

N1 and N1P1 amplitudes of the summed responses for 38 normal subjects For 23 subjects both the left (OS) and right (OD) eyeswere measured but only their left eyes (OS) were used in calculating the means

Full-Field L- to M-Cone DrivenAmplitude Ratios

In Table 1 one can compare the ratios of the L- to M-cone driven N1 (column 6) and N1P1 (column 9)component The average L- to M-cone driven amplituderatios for the 38 subjects is 165 plusmn 112 for the N1component and 219 plusmn 143 for the N1P1 component(In those 23 subjects from whom mfERGs weresimultaneously recorded in both eyes only the mfERGresponses from their left eyes were used in calculatingthese averages) The average value for the N1P1component agrees perfectly with the scaling factor (22)calculated for the full-field summed responses ( Figure5B

lowest trace) Although the L- to M-cone drivenamplitudes are typically larger than unity there isconsiderable variability among observers The N1component ratios range from 017 to 450 and the N1P1component ratios from 06 to 710 Interestingly thesmallest values obtained for both the N1 (021 plusmn 006averaged over both eyes) and N1P1 (011 plusmn 001 averagedover both eyes) ratios are for the female carrier of protanopia (JB) for whom the strength of the M-conedriven N1 (07 plusmn 014 nVdeg 2) and N1P1 (18 plusmn 014nVdeg 2) responses is considerably greater than that forthe L-cone driven N1 (015 plusmn 007 nVdeg 2) and N1P1(02 plusmn 00 nVdeg 2) responses




1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B

Figure 5 mfERG responses for L- (red curves) and M- (greencurves) cone driven signals averaged for 38 normal subjectsFor 23 subjects both the left (OS) and right (OD) eyes weremeasured but only their left eyes (OS) were used in theaverage The lowest pair of traces is for the full-field summedresponse see Figure 1 for the numbered traces for the ringanalysed responses A The unadjusted mean L- and M-conedriven amplitudes B The M-cone driven amplitude normalizedto the N1P1 peak of the L-cone driven one

L- and M-Cone Driven Amplitudes

and Retinal EccentricityFigure 6A plots the change in mean L- (red curves)

and M- (green curves) cone driven N1 and N1P1amplitudes as a function of retinal eccentricity (the values

were obtained after summing the responses for allsubjects within the concentric rings depicted in Figure 1 )For both the N1 and N1P1 components the amplitudesare largest for the central ring (5deg dia) and typically fall

off sharply with eccentricity up to 10deg in the periphery and remain almost constant thereafter Figure 6B showsthe L- to M-cone driven amplitude ratios for N1 andN1P1 determined from the same data as a function of retinal eccentricity They are consistent with the scalingfactors derived in Figure 5B by normalizing the M-conedriven N1P1 peaks to the L-cone driven ones Mean

values and standard deviations can be calculated by averaging the individual data analysed according to ringsFor the central fovea (5deg dia) the mean ratios are 13 plusmn 08 (N1) and 14 plusmn 06 (N1P1) whereas for the annularring centred at 40deg in the periphery they are 17 plusmn 12(N1) and 23 plusmn 20 (N1P1)

Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6

L-cone driven N1L-cone driven N1P1M-cone driven N1P1M-cone driven N1

Eccentricity (deg)

L - M

c o n e - d r i v e n a m p l i t u

d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B

Figure 6 A The variation in the amplitude of the N1 (filled

circles) and N1P1 (open circles) components of the L- (redsymbols) and M- (green symbols) cone driven mfERGs as afunction of retinal eccentricity The individual hexagonalresponse traces have been summed according to the sixconcentric rings depicted in Figure 1 B The L- to M-conedriven mfERG ratios derived from the summed responses asa function of retinal eccentricity for both the N1 (open symbols)and N1P1 (filled symbols) components




Table 2 The N1 and P1 Latencies of the L- and M-Cone Driven mfERGs in 38 Trichromats

Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17


N1 and P1 latencies of the summed responses for 38 normal subjects For 23 subjects both the left (OS) and right (OD) eyes weremeasured but only their left eyes (OS) were used in calculating the means

L- and M-Cone Driven LatenciesFigure 5 (lower traces) clearly illustrates the difference

in latency between the average L- and M-cone driven fullfield mfERG signals The difference for both the N1 andP1 components is quantified for each subject in Table 2(see columns 6 and 9 respectively)

The mean latency of the N1 component of the M-cone driven signal (156 plusmn 17 ms) is slightly advancedrelative to that of the L-cone driven signal (162 plusmn 13 ms)(In those 23 subjects from whom mfERGs weresimultaneously recorded in both eyes only the mfERGresponses from their left eyes were used in calculatingthese averages) However the difference is not statistically

significant and there is considerable variability amongsubjects in the latency difference In fact for 12 of the 38subjects the L-cone driven N1 latency is actually shorterthan the M-cone driven one In contrast the meanlatency of the P1 component of the M-cone driven signal(280 plusmn 26 ms) is significantly advanced (paired t test p =015 N = 38) relative to that of the L-cone driven signal(290 plusmn 19 ms) For only 8 of the subjects is the L-conedriven P1 latency shorter than the M-cone driven one




L- and M- Cone Driven Latency andRetinal Eccentricity

Figure 7 plots the mean latencies of the L- and M-conedriven mfERG signals analysed within concentric rings (seeFigure 1 ) For the N1 component (filled symbols N = 34 for4 of the subjects [JB MA WJ and CJ] the signals weretoo noisy for a reliable ring analysis) the latencies of the M-and L-cone driven signals are very similar and do not vary significantly with retinal eccentricity In contrast for the P1component (open symbols N = 37 for subject SH thesignals were too noisy for a ring analysis) both the M- and L-cone driven signals show a significant decrease in latency

with eccentricity Except for the most central ring (5deg dia)the P1 latencies of the M- and L-cone driven signals alsodiffer significantly For all other rings the M- cone drivenlatency is significantly advanced relative to the L-cone drivensignal These changes are also obvious when inspecting thering analysis provided in Figure 5B (traces 1 to 6)

Eccentricity (deg)0 10 20 30 40

L a

t e n c y

( m s

)

14

16

18

20

22

24

26

28

30

3234

L-cone driven N1M-cone driven N1L-cone driven P1M-cone driven P1

Figure 7 The variation in the latency of the N1 (filled symbols)and P1 (open symbols) components of the L- (red symbols) andM- (green symbols) cone driven mfERGs as a function of retinaleccentricity The individual hexagonal response traces havebeen summed according to the six concentric rings depicted inFigure 1 Means and standard deviations are shown for 34observers for the N1 (SH MA WJ and CJ were excluded)and 37 observers for the P1 (SH was excluded)

Correlation with HeterochromaticFlicker PhotometryLarge differences between the strengths of inferred M-

and L-cone isolated responses have been reported inprevious psychophysical ( De Vries 1946 1948 Ciceroneamp Nerger 1989 Vimal et al 1989 Pokorny et al 1991

Wesner et al 1991 Kremers et al 2000 ) and ERG flickerstudies ( Carroll et al 2000 Kremers et al 2000 ) Theresults from different procedures measured in the sameobservers can correlate highly with one another (see

Kremers et al 2000 ) and have been used to draw inferences about the relative L- to M-cone numbers in theretinal mosaic To determine if our L- to M-cone drivenmfERG amplitude ratios also correlate with such measures

we derived estimates of L- to M-cone ratios from full-spectrum (400 to 690 nm) heterochromatic flickerphotometric (HFP) thresholds measured in 16 of our 38

observers The HFP measurements were made for a 2deg dia25 Hz flickering target presented in counterphase with areference light (560 nm) on a xenon arc background (3 logphotopic td color temperature 6500 K) 16deg dia (for adetailed description of the procedure see Kremers UsuiScholl amp Sharpe 1999 ) Therefore in makingcomparisons with the HFP data we restricted the mfERGdata to the inner part of the visual field to minimizeregional variations influencing the results Thecomparisons are shown in Figure 8 for both the N1 andN1P1 components for the summed inner 20deg mfERGresponse (ie grouped over the four inner rings) The bestcorrelation r 2=083 is obtained between the 2deg HFP data

and the 20deg N1P1 data (slope = 069) In contrast thecorrelation between the 2deg HFP data and the 20deg N1 datais r 2=068 (slope = 052) and the correlation between the2deg HFP data and the inner 5deg mfERG N1P1 data is only r 2=051 (slope = 030) As the HFP data have a symmetricaldistribution on a log scale (see references cited in Table 1b

LM cone ratio estimate from HFP0 1 2 3 4 5 L

- t o M - c o n e

d r i v e n

E R G

a m p

l i t u d e r a

t i o

0

1

2

3

4

5ERG N1P1 (20deg)ERG N1 (20deg)

Figure 8 L-cone to M-cone driven amplitude ratios derivedfrom the N1 (open symbols) and N1P1 (filled symbols)amplitudes of isolated cone driven mfERG responses plottedagainst estimates derived from linear fits to (2deg) HFPthresholds in 16 normal observers The comparisons with theHFP are shown for hexagonal responses summed within theinner 20deg of the visual field for the N1 (slope = 052 r

2=068large dashed lines) and N1P1 (slope = 069 r

2=083 smalldashed lines) components The solid line (slope = 10)indicates a perfect correlation and the locus of equal valuesFor one subject (marked with a small star) L- to M-cone drivenratios derived from the N1 and N1P1 amplitudes are the sameSee text for other details




of Pokorny et al 1991 ) correlations were also obtainedbetween the HFP data and the log L- to M-cone drivenamplitude ratio These values were similar to those abover 2=072 for the 2deg HFP and the 20deg N1P1 data r 2=070 forthe 2deg HFP and the 20deg N1 data and r 2=065 for the 2degHFP and the inner 5deg mfERG N1P1 data

DiscussionInferring L- to M-Cone Ratios FrommfERG Amplitudes

Given that the mfERG provides a topographicalrepresentation of these cone driven signals we wanted todetermine if those signals could be used to draw inferences about L- to M-cone ratios in the retina

Admittedly in doing so we must be cautious because theinterpretation of the elicited mfERG waveforms iscomplicated The only previous study concerned with L-and M-cone isolating stimuli and the mfERG ( Klistorner

Crewther amp Crewther 1998 ) varied the contrast of thecolor hexagonal elements so as to pass through theisoluminance condition (ie so that there was apparently only red-green opponent channel and no luminancecontrast information available) Their silent substitutioncondition for the L cones was near a contrast ratio of 049or about 35 whereas their silent substitution for the Mcones was near a greenred ratio of 139 or about 16Thus they could not directly compare L- and M-conedriven response amplitudes and their data cannot beused to derive L- to M-cone driven ratios

To relate the relative amplitudes of L- and M-conedriven mfERGs to L- and M-cone ratios in the retinalmosaic it is necessary to start with stimuli that provideequivalent L- or M-cone inputs to the rest of the visualsystem For this reason we chose the mean luminances of our L- (192 cdm 2) and M- (338 cdm 2) cone isolatingstimuli to obtain equal quantal catches ensuring thatboth cone classes were stimulated at the same adaptinglevel Additionally it is necessary to demonstrate that thefour following conditions are satisfied (1) that theamplitude versus intensity relations are similar for boththe L- and M-cone isolating stimuli (2) that the relationsbetween the L- and M-cone driven signals are constant atdifferent contrast levels (3) that the response waveformsto the L- and M-cone isolating stimuli are similar and (4)that the mfERG the L- to M-cone estimates correlate withestimates obtained with other techniques

Figures 3 and 4 demonstrate that the first two criteriahold to a first approximation namely that the amplitude

versus intensity functions of the L- and M-cone drivensignals are similar and the two signals are linear withcontrast for the values falling within the criticalmeasuring range Further the comparisons in Figure 8 indicate that the fourth criterion is also roughly fulfilledinsofar as the 20deg mfERG (N1P1) and 2deg HFP estimates

obtained from the same group of observers correlate withone another And the average L- to M-cone drivenamplitude ratio of 219 plusmn 143 for the N1P1 componentcorrelates very well with the values found by many otherpsychophysical and electroretinographic studiesestimating the relative numbers of L- and M- cones (cfKremers et al 1999 ) In addition the M-cone dominated

estimates obtained from the mfERG recordings in thecarrier for protanopia accord with other reportssuggesting a strong dominance of the M cones in suchcarriers ( Crone 1959 Miyahara Pokorny Smith Baronamp Baron 1998 )

Figure 5 suggests that the third criterion uniformity of the L- and M-cone driven waveforms also roughly holds not only for the full field but also for the ringanalyses (granted the absolute amplitudes of the mean L-and M-cone driven signals differ [which was to beexpected] and the relative sizes of their N1 to N1P1 peaksand their N1 and P1 latencies differ as well) This resultsin the magnitude of the L- to M-cone driven amplitude

ratio being greater for the N1P1 component than for theN1 component However the general similarity betweenthem suggests that our simplifying assumptions arereasonable at least to a first approximation

L- to M-Cone Ratios and RetinalEccentricity

Given the differences in waveform between the L-and M-cone driven signals in the peripheral retina only tentative conclusions can be drawn about the change in L-to M-cone driven amplitude ratio with eccentricity Onthe one hand the difference between the central (5deg dia)and peripheral (gt10deg eccentricity) LM-cone amplituderatios for both N1 and N1P1 accords with the results of preliminary molecular biological studies in which the L-to M-cone pigment mRNA ratio increased substantially between central and peripheral patches ( Hagstrom et al1997 1998 ) But the increase in the mfERG L- to M-cone driven amplitude ratios may only be apparent Itseems unlikely that most individuals have a more similarL- to M-cone ratio in the very central fovea than in theparafoveal and more peripheral regions Indeed thisinterpretation is supported by direct visualization of thefoveal cone mosaic with adaptive optics In their studyRoorda and Williams (1999) found very different L- to M-cone ratios (about 111 and 381) in two color normalobservers measured in small (lt30 min of arc dia) patchesat 1deg eccentricity This is the sort of variability foundamong observers in the peripheral but not in the centralLM-cone ratio mfERG estimates

Thus we would argue that the differences in L- to M-cone ratios between the central and peripheral mfERGresponses may reflect other factors One of these may bethat the center element of the mfERG is more noiselimited than the peripheral elements However the mostimportant factor could be a change in gain between the




receptors and bipolars that depends upon eccentricityThe photopic mfERG like the photopic full-field ERG isdominated by the bipolar response (eg Horiguchi et al1998 Hare et al 2001 Hood et al 2002a ) As the sizeand mix of the bipolar cells change with eccentricity therelative gain of the L- and M-cone signal may be alteredThere are various ways the gain change argument can be

developed given a typical retinal cone mosaic in whichthe L cones predominate (say a 2L1M ratioarrangement) Consider first that the midget bipolarshave only a single cone in the center (ie either a L- or M-cone) but that the extent of the midget bipolar surroundsis spatially constrained so that the number of cone inputsdepends upon cell type In that case the L- to M-conedriven ratio in the central fovea may be underestimatedbecause midget cone bipolar surrounds will reflect thelocal ratio if they sample cones selectively either all M- orall L-cones (ie there will be more L cones opposing anM cone ON center midget bipolar cell than M conesopposing an L cone ON center midget bipolar) Even

though they may have twice as many L-cone center ON-bipolar cells their responses will be smaller than those of the M-cone center ON bipolar cells because theirsurrounds will have twice the input compared with the Mcenter ON-bipolar cells On the other hand if the inputto the surround is selective but not spatially constrainedso that it always consists of the same number of cones (say 6) but of the other cone type (ie either all M- or all L-cones) then the response of an L-cone center midget cell

will be inhibited by the input of 6 M cones and theresponse of the M-center midget bipolar cell will beinhibited by 6 L cones The influence on sensitivity should be roughly the same But if the input to thesurround is not spatially constrained and is random andnonselective (which seems the most likely possibility)then the response of both the L-cone center and M-conecenter midget bipolar cells would be inhibited by twice asmany L cones as M cones and the L-cone center wouldhave a smaller response due to greater ldquoself-inhibitionrdquoThus the net effect would be a smaller L- to M-conedriven amplitude ratio in the central fovea than in theperiphery

It is important not to interpret these latency differences as directly reflecting differences in theresponse properties of the L- and M-cones per se This isfor several reasons First the mfERG is a complex

waveform If for example the positive componentdriving P1 (driven in part by the ON-bipolars [the PIIcomponent of Granit]) is slightly faster for the M-cone

isolation mode than for the L-cone isolation mode thenthe implicit time of N1 which is really the algebraic sumof the ON-bipolar cell response and a negativepotential(s) will be shorter for the M-cone than for the L-cone driven signals Second the differences in N1 and P1latency between the L- and M-cone driven mfERG signalsare not found in the central fovea (see Figure 7 ) wherethe amplitude evidence suggests that post-receptoralcomponents distort the waveforms the least (see Figure 5 )Third the differences in latency between the L- and M-cone driven signals do not depend on the relativedifferences in the size of the L- and M-cone drivenamplitudes Larger amplitude signals are not associated

with longer latencies (ie the N1 and P1 latency differences between the L- and M-cone driven signalsdepend on neither the L- to M-cone driven N1 nor on theL- to M-cone driven N1P1 amplitude ratio)

ConclusionsThe 20deg L- to M-cone driven N1P1 amplitude ratios

correlate with the psychophysically measured 2deg HFP dataand estimates obtained in each observer for the N1 andN1P1 components correlate highly with one another ( r 2 =068 and 083 respectively) Therefore we can concludethat the L- to M-cone ratio in the foveal center as well asperiphery differs with individuals Although L- to M-conedriven amplitude ratios are larger for N1P1 versus N1 andlarger for gt5deg versus lt 5deg these ratios vary amongindividuals and are highly correlated within an individualThe changes with retinal eccentricity probably do notmerely reflect noise limitations (the central mfERGresponses are more noise limited than the peripheral ones)nor an abrupt change in the L- to M-cone ratio of thecentral as contrasted with the peripheral retina Ratherthey emphasize the need to look more closely at differencesbetween central and peripheral retinal processing Theopportunity to examine the central responses in terms of different pathway contributions is afforded by the mfVEP

which overcomes the signal to noise limits imposed onsmall central visual fields in the mfERG It exploits thecortical magnification of the foveal response to obtainestimates of visual processing within the inner 12deg(radius) of visual field where the parvocellular pathwaysdominate We have recently recorded mfVEP responsesto L- and M-cone isolating stimuli ( Hood et al 2002b )The central mfVEP responses are similar in amplitudeand waveform for observers but the peripheral responsesdiffer in amplitude and waveform with the L-cone

Latency Differences Between theL- and M-Cone Driven Signals

Our results reveal a 10-ms difference in the latency of the P1 component between the L- and M-cone drivensignals with the M-cone driven response beingsignificantly advanced The difference between the L- andM-cone driven N1 latencies is smaller (06 ms) and is notsignificant The P1 results accord with previous resultsreported by Weithmore and Bowmaker (1995) and by Kremers et al (1999) who found a phase difference equalto circa 14 ms between the L- and M-cone drivenGanzfeld flicker ERGs




Hare W A Ton H Ruiz G Feldmann B WijonoM amp WoldeMussie E (2001) Characterization of retinal injury using ERG measures obtained withboth conventional and multifocal methods inchronic ocular hypertensive primates InvestigativeOphthalmology amp Visual Science 42 127-136[PubMed]

modulation producing larger responses Taken togetherthe mfVEP and mfERG results suggest that there is achange in gain in the PC pathway before the mfVEP isgenerated in area 17 and that some of this gain changemay be occurring before the midget bipolar cell responsein the outer plexiform layer

Acknowledgments Hood D C (2000) Assessing retinal function with themultifocal technique Progress in Retinal and EyeResearch 19 607-646 [PubMed] This work was supported by a Lilly-und-Hermann-

Schilling-Stiftung (Essen Germany) Professorship and by grants SFB 430 (TP A6) and Sh235-2 awarded by theDeutsche Forschungsgemeinschaft (Bonn-Bad GodesbergGermany) to LTS and by grants from the Landesswer-punkprogramm Baden-Wuumlrtemberg and the fortuumlne-Programme (780-0-0 Universitaumlts-Klinikum Tuumlbingen)awarded to HJ and LTS The authors would like tothank Emanuela de Luca for help with the graphics

Hood D C Frishman L J Saszik S amp ViswanathanS (2002a) Retinal origins of the primate multifocalERG Implications for the human responseInvestigative Ophthalmology amp Visual Science 43 1673-1685 [PubMed]

Hood D C Seiple W Holopigian K amp Greenstein V (1997) A comparison of the components of themulti-focal and full-field ERGs Visual Neuroscience 314 533-544 [ PubMed ]

Commercial Relationships None

References Hood D C Yu A L Zhang X Albrecht J Jaumlgle Hamp Sharpe L T (2002b) The multifocal visualevoked potential and cone-isolating stimuliImplications for L- to M-cone ratios andnormalization Journal of Vision 2(2) 178-189httpjournalofvisionorg224 DOI101167224 [ Link ]

Carroll J McMahon C Neitz M amp Neitz J (2000)Flicker-photometric electroretinogram estimates of LM cone photoreceptor ratio in men withphotopigment spectra derived from genetics Journalof the Optical Society of America A 17 499-509[PubMed] Horiguchi M Suzuki S Kondo M Tanikawa A amp

Miyake Y (1998) Effect of glutamate analogues andinhibitory neurotransmitters on theelectroretinograms elicited by random sequencestimuli in rabbits Investigative Ophthalmology amp Visual

Science 39 2171-2176 [PubMed]

Cicerone C M amp Nerger J L (1989) The relativenumbers of long-wavelength-sensitive to middle-

wavelength-sensitive cones in the human foveacentralis Vision Research 26 115-128 [ PubMed ]

Crone R A (1959) Spectral sensitivity in color-defectivesubjects and heterozygous carriers American Journalof Ophthalmology 48 231-238

Klistorner A Crewther D P amp Crewther S G(1998) Temporal analysis of the topographic ERGChromatic versus achromatic stimulation VisionResearch 38 1047-1062 [PubMed] De Vries H L (1946) Luminosity curve of trichromats

Nature 15 736-737Kremers J Usui T Scholl H P amp Sharpe L T

(1999) Cone signal contributions toelectroretinograms in dichromats and trichromatsInvestigative Ophthalmology amp Visual Science 40 920-930 [PubMed]

De Vries H L (1948) The heredity of the relativenumbers of red and green receptors in the humaneye Genetica 24 199-212

Hagstrom S A Neitz J amp Neitz M (1997) Ratio of ML pigment gene expression decreases with retinaleccentricity In C R Cavonius (Ed) Colour vision

deficiencies XIII (pp 59-65) Dordrecht TheNetherlands Kluwer

Kremers J Scholl H P N Knau H Berendschot TT T M Usui T amp Sharpe L T (2000) LMcone ratios in human trichromats assessed by psychophysics electroretinography and retinaldensitometry Journal of the Optical Society of America

A 17 517-526 [PubMed] Hagstrom S A Neitz J amp Neitz M (1998) Variation

in cone populations for red-green color visionexamined by analysis of mRNA NeuroReport 9 1963-1967 [PubMed]

Miyahara E Pokorny J Smith V C Baron R ampBaron E (1998) Color vision in two observers withhighly biased LWSMWS cone ratios VisionResearch 38 601-612 [PubMed]




Nathans J Thomas D amp Hogness D S (1986)Molecular genetics of human color vision The genesencoding blue green and red pigments Science 232 193-232 [PubMed]

Pokorny J Smith V C amp Wesner M F (1991) Variability in cone populations and implications In AValberg amp B B Lee (Eds ) From pigments to

perception Advances in understanding visual processes (pp 1-9) New York Plenum PressPugh E N (1988) Vision Physics and retinal

physiology In R C Atkinson (Ed) Stevens handbookof experimental psychology(pp 75-163) New York

WileyRoorda A amp Williams D R (1999) The arrangement

of the three cone classes in the human eye Nature397 520-522 [PubMed]

Sharpe L T Stockman A Jaumlgle H Knau H ampNathans J (1999) L- M- and L-M-hybrid conephotopigments in man Deriving λ max from flickerphotometric spectral sensitivities Vision Research 39 3513-3525 [PubMed]

Sieving P A Murayama K amp Naarendorp F (1994)Push-pull model of the primate photopicelectroretinogram A role for hyperpolarizingneurons in shaping the b-wave Visual Neuroscience11 519-532 [PubMed]

Sutter E E (1991) The fast m-transform A fastcomputation of cross-correlations with binary m-sequences Society for Industrial and AppliedMathematics 2 686-694

Sutter E E amp Tran D (1992) The field topography of ERG components in man I The photopicluminance response Vision Research 32 433-446[PubMed]

Stockman A amp Sharpe L T (1998) Human conespectral sensitivities A progress report VisionResearch 38 3193-3206 [PubMed]

Stockman A amp Sharpe L T (1999) Cone spectralsensitivities and color matching In K Gegenfurtneramp L T Sharpe (Eds) Color vision From genes toperception (pp 53-88) Cambridge CambridgeUniversity Press

Stockman A amp Sharpe L T (2000) The spectralsensitivities of the middle- and long-wavelengthsensitive cones derived from measurements inobservers of known genotype Vision Research 40 1711-1737 [PubMed]

Vimal R L P Pokorny J Smith V C amp Shevell SK (1989) Foveal cone thresholds Vision Research29 61-78 [PubMed]

Weithmore A V amp Bowmaker J K (1995) Shortcommunication Differences in the temporalproperties of human longwave- and middlewave-sensitive cones European Journal of Neuroscience 7 1420-1423 [PubMed]

Wesner M Pokorny J Shevell S K amp Smith V C(1991) Foveal cone detection statistics in color-normals and dichromats Vision Research 31 1021-1037 [PubMed]

Wyszecki G amp Stiles W S (1982) Color scienceConcepts and methods quantitative data und formulae (2nd ed) New York Wiley




with an increase to 301 in the mid-periphery (circa 41degeccentricity) But the resolution obtained with thistechnique so far does not allow conclusions to be madeconcerning the cone ratio in the central 10deg

The cone isolating mfERG offers advantages thatnicely compensate for the resolution and regionallimitations inherent to the psychophysical ERG and

mRNA studies With the mfERG technique it is possibleto isolate L- and M-cone driven signals with a resolution of about 5deg (dia) of visual angle over a large visual area (84deg x 75deg) However the straightforward interpretation of mfERG amplitudes with regard to L- and M-conedistributions is complicated by the complexity of themfERG waveform It consists of two initial majorcomponents which are analogues of the a- and b-waves of the full-field flash ERG ( Hood Seiple Holopigian ampGreenstein 1997 ) an initial negative deflection (N1)followed by a positive peak (P1) In addition there is asecond prominent negative deflection (N2) present as well

Chemical isolation of components of both the full-

field and mfERG of monkeys has established that the N1component is largely an OFF-bipolar response withrelatively small contributions from the inner retina andthe cone photoreceptors ( Sieving Murayama ampNaarendorp 1994 Horiguchi Suzuki Kondo Tanikawaamp Miyake 1998 Hare et al 2001 Hood 2000 HoodFrishman Saszik amp Viswanathan 2002a ) In contrastthe P1 component is predominantly produced by theonset of the ON-bipolar cells and to some extent by theoffset of the OFF-bipolars and the N2 component islargely produced by the offset of both the ON-bipolarsand OFF-bipolars ( Hood et al 2002a ) Obviously any attempt to relate the ratio of L- to M-cone driven mfERGsto L- to M-cone photoreceptor mosaic ratios requires acomprehensive model of how these distal neuralcomponents alter the waveform Nevertheless asimplified model assuming a close relation between L-and M-cone driven mfERG amplitudes and L- to M-coneratios may be justified under limited conditions

Here we present evidence to establish such a relationincluding (1) comparisons of the L- and M-cone isolatingresponse waveforms (2) their amplitude versus intensity responses at five levels (3) their contrast responses at twolevels and (4) correlations between the mfERG L- to M-cone estimates and estimates obtained in the same groupof observers using a psychophysical HFP technique Theevidence analysed topographically is roughly consistent

with the simplified model although the model holds less well for the peripheral retina (gt 5deg of visual angle) than itdoes for the central fovea (lt 5deg) Additionally the dataprovide insight into how regional differences in theamplitudes and latencies of the L- and M-cone drivenmfERG signals can be related to variations in the L- to M-cone ratios and in gain factors in the outer retina Finallythis work serves as a basis for interpreting evidenceobtained from L- and M-cone isolating multifocal visually evoked potentials (mfVEPs) relying on the same cone

isolating procedures that are presented in anaccompanying study ( Hood et al 2002b )

MethodsSubjects

Thirty-eight trichromats 25 males and 13 females(aged 19 to 51 years) participated in our study All hadnormal (corrected) visual acuity and were classified ascolor normal on the basis of their performance onstandard color vision tests including the Ishiharapseudoisochromatic plates and the Nagel Type Ianomaloscope One of the normal trichromat females(JB) is a heterozygotic carrier for protanopia asestablished by the family pedigree (the maternalgrandfather is a protanope) and by preliminary moleculargenetic analysis In addition 4 protanopes (aged 21 to 33

years) and 5 deuteranopes (aged 22 to 38 years) weretested The classification of protanopia and deuteranopia

was based on Rayleigh red-green equation matches madeon the Nagel Type I anomaloscope (Schmidt amp HaenschBerlin Germany) The genotypes of the dichromats weredetermined by molecular genetic (DNA) analysis of

venous blood samples There was no evidence of afunctional M-cone opsin gene in the deuteranopes or of afunctional L-cone opsin gene in the protanopes In allsubjects one or both eyes were maximally dilated (circa 8mm) by application of a mydriatic (05 tropicamide)and kept light-adapted before and during the mfERGrecording Corneal mfERG responses were measured witha DTL fiber electrode The reference and ground skinelectrodes were attached to ipsilateral temple and the

forehead respectively Informed consent was obtainedfrom all subjects after explanation of the purpose andpossible consequences of the study This study wasconducted in accordance with the tenets of theDeclaration of Helsinki and with the approval of theInstitutional Ethics Committee in HumanExperimentation at the University of Tuumlbingen

Visual Stimulation and mfERGRecording

The stimulus was generated on a flat-screen SONY Trinitron monitor with a resolution of 1024 x 768 pixelsIt consisted of 103 hexagonal elements (see Figure 1 )

which subtended 84deg x 75deg of visual angle at a viewingdistance of 18 cm Each element was alternated in colorpseudorandomly between two values carefully selected tomodulate activity in a single cone class The mfERGstimulation and data collection and analysis wereperformed by VERIS system software (Version 301)from EDI [see Sutter (1991) and Sutter amp Tran (1992) formore details] The appropriate colors or cone isolatingstimuli were calculated from the emission spectra of thethree phosphors and the Stockman and Sharpe cone

















25deg

37deg

12deg

58deg

73deg

80deg

6

54

21

3









L-conemodulation

M-conemodulation

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

D e u

t e r a n o p e

P r o

t a n o p e

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

C D





Intensity ()20 40 60 80 100

L a

t e n c y

( m s

)

10

15

20

25

30

35

A m p

l i t u d e

( n v d e g

2 )

0

2


Intensity ()20 40 60 80 100

C D

L-cone modulation

05 nVdeg 2

0 20 40 60 80 ms

158 -06291 1680

174 -04291 1660

183 -06307 1040

241 -04307 0420


158 -10291 18100

I n t e n s i t y

( )

A B

05 nVdeg 2

0 20 40 60 80 ms

166 -08282 14

166 -08307 10

191 -06315 08

208 -04307 06

80

60

40

20

100 158 -10266 16


M-cone modulation

P1

N1












0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

L-conemodulation

M-conemodulation

EL

MK

47

27

47

27



















Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














L a

t e n c y

( m s

)

14

16

18

20

22

24

26

28

30

3234











- t o M - c o n e

d r i v e n

E R G

a m p

l i t u d e r a

t i o

0

1

2

3

4






































































































25deg

37deg

12deg

58deg

73deg

80deg

6

54

21

3









L-conemodulation

M-conemodulation

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

D e u

t e r a n o p e

P r o

t a n o p e

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

C D





Intensity ()20 40 60 80 100

L a

t e n c y

( m s

)

10

15

20

25

30

35

A m p

l i t u d e

( n v d e g

2 )

0

2


Intensity ()20 40 60 80 100

C D

L-cone modulation

05 nVdeg 2

0 20 40 60 80 ms

158 -06291 1680

174 -04291 1660

183 -06307 1040

241 -04307 0420


158 -10291 18100

I n t e n s i t y

( )

A B

05 nVdeg 2

0 20 40 60 80 ms

166 -08282 14

166 -08307 10

191 -06315 08

208 -04307 06

80

60

40

20

100 158 -10266 16


M-cone modulation

P1

N1












0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

L-conemodulation

M-conemodulation

EL

MK

47

27

47

27



















Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














L a

t e n c y

( m s

)

14

16

18

20

22

24

26

28

30

3234











- t o M - c o n e

d r i v e n

E R G

a m p

l i t u d e r a

t i o

0

1

2

3

4


























































































L-conemodulation

M-conemodulation

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

AS

CB

MH

CH

MFe

MFr

JJ

HN

AZ

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

D e u

t e r a n o p e

P r o

t a n o p e

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

C D





Intensity ()20 40 60 80 100

L a

t e n c y

( m s

)

10

15

20

25

30

35

A m p

l i t u d e

( n v d e g

2 )

0

2


Intensity ()20 40 60 80 100

C D

L-cone modulation

05 nVdeg 2

0 20 40 60 80 ms

158 -06291 1680

174 -04291 1660

183 -06307 1040

241 -04307 0420


158 -10291 18100

I n t e n s i t y

( )

A B

05 nVdeg 2

0 20 40 60 80 ms

166 -08282 14

166 -08307 10

191 -06315 08

208 -04307 06

80

60

40

20

100 158 -10266 16


M-cone modulation

P1

N1












0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

L-conemodulation

M-conemodulation

EL

MK

47

27

47

27



















Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














L a

t e n c y

( m s

)

14

16

18

20

22

24

26

28

30

3234











- t o M - c o n e

d r i v e n

E R G

a m p

l i t u d e r a

t i o

0

1

2

3

4




























































































0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

A B

0 10 20 30 40 50 60 70 80 ms 2 n V

d e g

2

L-conemodulation

M-conemodulation

EL

MK

47

27

47

27



















Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

DU OS M 08 04 20 23 10 23

OD --- --- --- --- --- ---AY OS F 03 05 06 08 13 06

OD 06 05 12 14 13 11SH OS M 05 05 10 14 13 11

OD --- --- --- --- --- ---MS OS M 09 08 11 25 10 25

OD --- --- --- --- --- ---CW OS M 10 09 11 34 21 16

OD 11 09 12 33 21 16NB OS F 13 03 43 34 05 68

OD 10 03 33 36 06 60MB OS M 11 02 53 32 06 53

OD 13 02 63 36 05 71KF OS F 09 05 18 21 06 35

OD 07 04 18 23 10 23KG OS F --- --- --- --- --- ---

OD 03 07 04 10 17 06AW OS M 07 05 14 16 17 09

OD 04 05 08 10 12 08MH OS M 11 03 37 24 07 34

OD 08 02 40 19 07 27HA OS M 07 08 09 13 13 10

OD 07 14 05 14 24 06

HJ OS M 06 09 07 25 22 11OD 09 08 11 20 17 12

JB OS F 01 06 02 02 19 01OD 02 08 03 02 17 01

TS OS M 03 03 10 07 07 10OD 05 04 13 07 08 08

FG OS M 04 03 13 11 08 14OD 06 05 12 16 12 13

JK OS M --- --- --- --- --- ---OD 02 03 07 04 04 10

EA OS M 06 03 20 14 07 20OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 06 09 07 17 14 12

SK OS M 01 01 10 04 02 20OD --- --- --- --- --- 15

CS OS F 06 04 15 15 05 30OD 04 03 13 15 06 25

TB OS F 05 05 10 16 10 16OD 04 06 07 21 11 19

JA OS M 10 04 25 22 06 37




Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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Subject Eye Gender

L-coneN1

Amplitude(nVdeg 2)

M-coneN1

Amplitude(nVdeg 2)

Ratio LMN1

Amplitude

L-coneN1P1

Amplitude(nVdeg 2)

M-coneN1P1

Amplitude(nVdeg 2)

Ratio LMN1P1

Amplitude

OD 09 07 14 25 07 36SD OS M 05 04 13 10 05 20

OD --- --- --- --- --- ---

MA OS M 03 02 15 09 02 45OD --- --- --- --- --- ---

AN OS M 11 04 28 22 09 24OD --- --- --- --- --- ---

CH OS F --- --- --- --- --- ---OD 07 06 12 23 11 21

HM OS M --- --- --- --- --- ---OD 04 06 07 12 09 13

WJ OS M --- --- --- --- --- ---OD 05 02 25 16 03 53

CJ OS F 04 01 40 12 04 30OD --- --- --- --- --- ---

MK OS F 06 04 15 24 10 24OD 07 03 23 23 10 23

JH OS F 03 03 10 09 06 15OD 09 06 15 16 07 23

SW OS F 07 05 14 14 11 13OD 08 04 20 14 10 14

MJ OS M 05 03 17 14 07 20OD 05 03 17 16 07 23

TE OS M 06 03 20 17 05 34OD 09 02 45 24 08 30

EJ OS M 10 04 25 23 08 29

OD 06 03 20 21 12 18EL OS F 07 06 12 15 12 13

OD 06 04 15 16 13 12JS OS M 08 04 20 22 10 22

OD 08 04 20 22 10 22









1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

A B








Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms 1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1 n V

d e g

2

0 10 20 30 40 50 60 70 80 ms

1

2

3

4

5

6

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Eccentricity (deg)

A m p

l i t u d e

( n V d e g

2 )

0 10 20 30 40

0

1

2

3

4

5

6


Eccentricity (deg)

L - M


d e r a

t i o

0 10 20 30 4000

10

20

30

40 N1P1

A

B







Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

DU OS M 169 169 00 309 309 00

OD --- --- --- --- --- ---AY OS F 183 166 17 291 282 09OD 158 166 -08 291 266 25

SH OS M 159 159 00 272 253 19OD --- --- --- --- --- ---

MS OS M 140 169 -29 281 270 11OD --- --- --- --- --- ---

CW OS M 166 141 25 275 266 09OD 150 150 00 283 258 25

NB OS F 166 133 33 283 241 42OD 150 175 -25 275 270 05

MB OS M 175 191 -16 283 283 00

OD 166 183 -17 283 291 -08KF OS F 183 141 42 274 266 08

OD 133 158 -25 266 249 17KG OS F --- --- --- --- --- ---

OD 174 166 08 315 291 24AW OS M 158 183 -25 274 282 -08

OD 166 183 -17 299 299 00MH OS M 166 133 33 282 332 -50

OD 158 191 -33 299 307 -08HA OS M 150 169 -19 318 300 18

OD 150 159 -09 30 262 38

HJ OS M 197 159 38 30 290 10OD 197 159 38 30 300 00

JB OS F 169 151 18 281 272 09OD 131 178 -47 253 281 -28

TS OS M 159 140 19 309 300 09OD 178 150 28 328 309 19

FG OS M 169 159 10 309 290 19OD 169 159 10 29 290 00

JK OS M --- --- --- --- --- ---OD 169 140 29 272 243 29

EA OS M 178 169 09 346 340 06OD --- --- --- --- --- ---

ME OS M --- --- --- --- --- ---OD 159 159 00 318 309 09

SK OS M 141 166 -25 316 282 34OD --- --- --- --- --- ---

CS OS F 166 158 08 282 299 -17OD 166 158 08 282 282 00

TB OS F 149 149 00 266 282 -16OD 191 174 17 282 299 -17

JA OS M 166 149 17 282 307 -25




Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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Subject Eye Gender

L-coneN1

Latencies(ms)

M-coneN1

Latencies(ms)

DifferenceL-M

N1 Latency

L-coneP1

Latencies(ms)

M-coneP1

Latencies(ms)

DifferenceL-M

P1 Latency

OD 166 150 16 291 27 21SD OS M 149 166 -17 282 307 -25

OD --- --- --- --- --- ---

MA OS M 166 141 25 291 249 42OD --- --- --- --- --- ---

AN OS M 149 158 -09 266 249 17OD 149 158 -09 274 274 00

CH OS F --- --- --- --- --- ---OD 166 149 17 266 264 02

HM OS M --- --- --- --- --- ---OD 158 133 25 307 241 66

WJ OS M --- --- --- --- --- ---OD 166 149 17 299 241 58

CJ OS F 174 141 33 287 316 -29OD --- --- --- --- --- ---

MK OS F 141 166 -25 274 291 -17OD 141 158 -17 274 291 -17

JH OS F 149 141 08 291 235 56OD 166 158 08 274 241 33

SW OS F 149 174 -25 279 274 05OD 158 174 -16 307 291 16

MJ OS M 158 191 -33 295 290 05OD 141 149 -08 291 316 -25

TE OS M 158 149 09 274 249 25OD 149 141 08 274 241 33

EJ OS M 174 140 34 316 316 00

OD 174 149 25 299 282 17EL OS F 166 166 00 299 266 33

OD 133 158 -25 282 266 16JS OS M 149 116 33 266 266 00

OD 158 149 09 274 291 -17














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The MfERG and Cone Isolating Stimuli

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Transcript of The MfERG and Cone Isolating Stimuli