A multi-stage account of binding in vision: Neuropsychological evidence

I review neuropsychological evidence on the problems patients can have in binding together the attributes of visual stimuli, following brain damage. The evidence indicates that there can be several kinds of binding deficit in patients. Damage to early visual processing within the ventral visual stream can disrupt the binding of contours into shapes, though the binding of form elements into contours can still operate. This suggests that the process of binding elements into contour is distinct from the process of binding contours into shapes. The latter form of binding seems to operate within the ventral visual system. In addition, damage to the parietal lobe can disrupt the binding of shape to surface information about objects, even when the binding of elements into contours, and contours into shapes, seems to be preserved. These findings are consistent with a multi-stage account of binding in vision, which distinguishes between the processes involved in binding shape information (in the ventral visual stream) and the processes involved in binding shape and surface detail (involving interactions between the ventral and dorsal streams). In addition, I present evidence indicating that a further, transient form of binding can take place, based on stimuli having common visual onsets. I discuss the relations between these different forms of binding.