A theory of the Benham Top based on center–surround interactions in the parvocellular pathway

✍ Scribed by Garrett T Kenyon; Dan Hill; James Theiler; John S George; David W Marshak

• Book ID: 103853674
• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 575 KB
• Volume: 17
• Category: Article
• ISSN: 0893-6080
• DOI: 10.1016/j.neunet.2004.05.005

✦ Synopsis

A model color-opponent neuron was used to investigate the subjective colors evoked by the Benham Top (BT). Color-opponent inputs from cone-selective parvocellular (P) pathway neurons with center-surround receptive fields were subtracted with a short relative delay, yielding a small transient input in response to a white spot. This transient input was amplified by BT-like stimuli, modeled as a thin dark bar followed by full-field illumination. The narrow bar produced maximal activation of the P-pathway surrounds but only partial activation of the P-pathway centers. Due to saturation, subsequent removal of the bar had little effect on the P-pathway surrounds, whereas the transient input from the P-pathway centers was amplified via disinhibition. Responses to BT-like stimuli became weaker as surround sensitivity recovered, producing an effect analogous to the progression of perceived BT colors. Our results suggest that the BT-illusion arises because coneselective neurons convey information about both color and luminance contrast, allowing the two signals become confounded.