ABSTRACT
The former hypothesis is reinforced by the specific effects of lesions of the right parietal cortex on visual-spatial attention: the resulting neuropsychological syndrome of hemineglect or extinction can be interpreted as due to the specific impairment of an attentional system in the absence of a primary sensory loss. Automatic processes are typically subserved by fast and rigid cerebral systems which are partly subcortical. The final stages of visual-spatial information processing in the dorsal system are probably subserved by the pre-frontal cortex where operations related to spatial working memory are believed to take place. A zoom lens metaphor has been widely used to describe the function of this system which is also presumably involved in binding the different attributes of an object thus allowing its integrated perception. The function of this system is to prepare the successive operations of a serial, capacity-limited system carrying out a detailed analysis of a restricted portion of visual space.
