DYNAMIC OPERATION AND COLUMNAR ORGANIZATION OF NEOCORTEX

The first objective of this program of research is to discover the dynamic operations of the cerebral neocortex; i.e., how any small region of the cortex operates upon its several inputs to produce its different and divergent outputs, and the meaning for function of its columnar and laminar organization. The second objective is to study these local processing operations simultaneously in several cortical areas that are linked to each other and to other cerebral structures in serial and parallel arrays that constitute distributed systems; we seek to understand the distributed function. Studies will be made in waking, behaving monkeys trained to emit behavioral acts particularly related to or controlled by the cortical areas and systems to be studied. Our strategy is to develop further and to apply experimentally methods for the chronic implantation within the cortex of several and ultimately many microelectrodes for the observation simultaneously of the activity of several and ultimately many cortical neurons. This will allow studies of the processing within cortical networks, the ensemble properties of significant samples of populations of cortical cells, and of different local cortical areas in distributed systems. These techniques and the accompanying methods for data analysis and synthesis will be used in four different investigations: (1) the neuronal operations within the motor and premotor cortex in the initiation and control of aimed movements of the arm and hand; (2) the distributed neuronal processing mechanisms in the somesthetic cortex during the detection of and discrimination between textural surfaces presented to the hand; (3) the dynamic processing operations in the somesthetic cortex during the detection of and discrimination between mechanical sinusoids of different amplitudes and frequencies, with particular reference to how processing differs in areas 3b, 1, 2, and 5, and the columnar, laminar, and distributed system aspects of that processing; and, (4) the intrinsinc dynamic operations of the visual cortex related to stereopsis and depth perception. These studies of different cortical areas and different cerebral systems are strongly linked together by common themes: the intrinsic and dynamic operations within the neocortex, the functional meaning of its columnar and laminar organization, and their relation to sensory and motor events and to certain aspects of the higher functions of the brain.