VSS 2003, Sarasota, Florida

Multiplicative Effect of Sustained and Transient Edge Adaptation on Peripheral Target Detection

Farshad Moradi1, Shinsuke Shimojo1,2

 

Visual Disappearance Phenomena

1 Computation and Neural Systems Program, California institute of Technology, Pasadena, CA 91125

2  NTT Communication Science laboratories (NTT Com. Sci. Lab.), Atsugi, Kanagawa, 243 Japan

Model

Induced

Spontaneous

Binocular Rivalry

Motion induced Blindness

(Bonneh et al, 2000)

Fading induced by transients

(Kanai & Kamitani, 2003)

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Troxler Fading

(Troxler, 1804)

Abstract

1) Presenting a low-contrast Gabor patch for 8 seconds and then flashing a 20-30ms high-contrast patch over it could elicit the perceptual disappearance of a subsequent low-contrast stimulus. 2) Neither low-contrast adaptation nor high-contrast flash alone had any considerable effect. 3) Adaptation components are phase-insensitive. 4) Suppression is selective for orientation. 5) The induction by the transient adaptation could be transferred to another location up to a few degrees.


Sustained adaptation to a low-contrast pattern followed by transient adaptation to a similar high-contrast pattern can induce perceptual disappearance of a subsequent low-contrast target

 

Oreintation Selectivity

Text Box: Firing frequencyText Box: offsetText Box: gain

 

CONCLUSIONS

 

·       Dissociation between sustained edge adaptation to a low contrast stimulus and transient edge adaptation to a high contrast stimulus.

·       Combinatory effect indicates synergy between contrast and edge adaptation.

·       Results can be explained in terms of contrast gain and offset of an optimal neural encoder.

·       Selectivity for orientation → Cortical sites for transient and sustained adaptations in induced-disappearance phenomenon.

·       Disappearance of the target involves non-local mechanisms, conceivably associated with top-down influence and contextual modulation.

·       Same mechanism may underlie suppression of edges in motion induced blindness or fading induced by visual transient.

 

Main experiment

Local versus Global

 

Co-axial versus Orthogonal

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References:

Bonneh, Y., S, Cooperman, A., & Sagi, D. (2001). Motion-induced blindness in normal observers. Nature. 411, 798-801.

Kanai, R., & Kamitani, Y. (2003). Time-locked perceptual fading induced by visual transients. Journal of Cognitive Neuroscience (in press).

 

 

 

 

 

 

 

Acknowledgement: Supported by the California Institute of Technology