Contingent adaptation in masking and surround suppressionHörmet Yiltiz1 , David J. Heeger1,2, Michael S. Landy1,2

1Department of Psychology, 2Center for Neural Science, New York University

Reference1. Westrick et al., J Neurosci, 2016.2. Aschner et al., SFN, 2016.

AcknowledgementsSupported by NIH EY 08266.

Contacthormet.yiltiz@nyu.eduAvailable online: http://hyiltiz.com/VSS2018.pdf

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T Y I S I O N

C I E N C E S

VS S

2018

Detection and cross-orientation suppression Appearance and surround suppressionIntroductionHebbian normalization model of adap-tation1: neurons that fire together more often inhibit each other more.

HypothesisContingent adaptation: presenting stimuli synchronously leads to greater suppression compared to asynchronous presentation.• Demonstrated in macaque physiology.• Untested in humans.

Conclusion• Contingent adaptation raises detection

threshold and changes appearance. • Supports the Hebbian normalization

model.

• Adapt: non-contingent or contingent • Measure: threshold contrast for detecting a masked grating

or or

Same Opposite

Opposite Opposite Same Same

Which center has higher contrast?Matching Non-matching

5Hz

or

Non-contingent Contingent

Which side has an extra grating?

3o

1.5o

MatchingNon-matching

Contingent adaptation results in stronger cross-orientation suppression and thus in-creased masked detection thresholds.

0.3

0.5

±15o

Mat

ched

con

tras

t

The center grating appears to have lower contrast when it matches the adapter, thus requires higher physical con-trast to match the other center grating.

Observer

±45o

Observer

±45o

Thre

shol

d co

ntra

st

±15o

0.1

0.03

Adapt

Test

Adapt

Test

• Adapt: vary center-surround contingency• Measure: perceived matching contrast

5Hz

0.001 0.1 0.40.5

1

Target contrast

Acc

urac

y

±15o

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