Abstract
A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world, and producing a structure that enables object-based attention and tracking of object identity. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields, but in addition, their responses are modulated (enhanced or suppressed) depending on the location of a 'figure' relative to the edge in their receptive field. Each neuron has a fixed preference for location on one side or the other. This selectivity is derived from the image context far beyond the classical receptive field. This talk will review evidence indicating that border ownership selectivity reflects mechanisms of object definition. The evidence includes experiments showing (1) reversal of border ownership signals with change of perceived object structure, (2) border ownership specific enhancement of responses in object-based selective attention, )3) persistence of border ownership signals in accordance with continuity of object perception, and (4) remapping of border ownership signals across saccades and object movements. Some of these findings can be explained by assuming that grouping circuits detect 'objectness' according to simple rules, and, via recurrent projections, enhance the low-level feature signals representing the object. This might be the mechanism of object-based attention. Additional circuits may provide persistence and remapping.
Meeting abstract presented at VSS 2013