Poster Vss

Visual Backward Masking: Feed-forward or Recurrent? Frouke Hermens (1), Gediminas Luksys (2), Wulfram Gerstner (2), Michael H Herzog (1) 1) Laboratory of Psychophysics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland 2) Laboratory of Computational Neuroscience, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, Switzerland

2D Wilson-Cowan model

Mask

Most models of visual backward masking either make use of a feedforward or a recurrent structure. Here, we show that a simple 2D Wilson-Cowan type network model, employing lateral connections only, can account for many masking phenomena.

Simulation results: U-shaped and monotonic masking functions Target

Introduction

50 High intensity mask Low intensity mask

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We

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Covariation with template

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Excitatory layer

Wi

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We 10

Inhibitory layer

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ISI (ms)

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Increasing the intensity of the mask changes the masking function from U-shaped to mononotic.

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Stimulus (300x140 pixels)

Mask

Target

Simulation results: Common onset masking and the effects of attention

Results: Shine-through 20 ms 10

300 ms

Early Intermediate Late

Percept Psychophysical Threshold T = 30 ms

T = 80 ms

25 grating

T = 22 ms

Covariation with template

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T = 30 ms

T = 80 ms

5 grating

T = 22 ms

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Mask continuation after target offset (ms)

Conclusions

gaps in grating

T = 22 ms

Contact: [email protected]

T = 30 ms

T = 80 ms

+ A simple 2D Wilson-Cowan type model can explain many basic temporal and spatial effects of masking + No feedforward or recurrent structures are needed to explain these effects