Abstract

The visual system rapidly detects and recognizes objects in the visual scene. One key element of object processing is the detection of the boundaries of the object. We hypothesize that boundary detection requires feedforward center-surround interactions combined with suppressive, horizontal interactions between neurons tuned for the same visual features. Boundary detection leads to enhanced firing-rates at the borders of an object, which could be used to rapidly solve simple object detection tasks. For more complex situations involving novel or overlapping objects it is necessary to invoke a more time consuming incremental grouping processes. We will discuss evidence for a region growing process that enhances the firing-rates of cells in early visual areas that represent the surfaces of objects. We will discuss how these processes interact with attention, how they are implemented by the laminar micro-circuitry of cortex, and how different glutamate receptors contribute to these processes to create perceptual organization.