CNS Seminar

Title: Subjective contours and border ownership cell activity

Abstract: Over the past two decades Rudiger von der Heydt and colleagues have identified cells with receptive fields inmonkey extra-striate visual cortex that code border ownership, a key distinction needed for scene analysis. These findings have been replicated and extended in the Tsao lab at Caltech. I argue here that the perception of subjective contours (incorrectly dubbed as illusory contours) reflect readouts of border ownership cell activity. As such, appearance of a subjective contour provides aunique opportunity to characterize the information that the visual system employs identify occluding contours. The results are best seen within an ecological optics framework and additionally specify the likely brain level of processing. The new findings also indicate a surprisingly powerful role for lines (as in line drawings) to code physical/optical relations in 3-D scenes.