The long term goal is to identify cortical circuits underlying cognitive functions. This endeavor requires the elucidation of the essential contributions that cerebral loci make to cognitive processes. The projects will concentrate on occipito-parietal (OP) & occipito-temporal (OT) contributions to visual perception and cognition of space, action and forms, and to memory. The specific aim of the proposed work is to test two interlinked hypotheses: 1) Each area within OP and OT cortices makes multiple, yet unique, combinations of essential contributions to perception, cognition and memory; 2) Permanent lesion-induced deactivations can be accompanied by neural compensations that attenuate and mask the magnitude of these contributions. Work will focus on cat middle and posterior suprasylvian cortices (areas 7, aMS, pMS, dPS, PSs and vPS), and the hypotheses will be tested by applying multi-site cooling deactivation (#1), or permanent lesion-induced deactivation (#2), to disrupt distinct combinations of a battery of specific visually guided behaviors. The data will be used to generate the first comprehensive compendium of the multiple and characteristic combinations of neural contributions each of the constituent areas in OP and OT cortices make to different aspects of perception, cognition and the memory. The compendium will highlight similarities, overlap, differences, lateralization, uniqueness and nested hierarchy of contributions areas make to cognitive and higher brain functions. The compendium is a requisite for accurately identifying and interpreting neural compensations that may emerge following cerebral lesions. Together, the acquired knowledge is essential for the future development of biologically-realistic, functionally-based models of cerebral operations. Moreover, the knowledge will: 1) form the foundation of future studies of emergent and higher-order integrative processes; and 2) guide future investigative studies on defective cerebral systems that underlie diminished cognitive function, agnosia, and visual neglect and other sequelae of damage of visuoparietal and visuotemporal regions.