Accession Number : ADA175539


Title :   Modeling and Simulation. II. Specificity Models for Visual Cortex Development.


Descriptive Note : Technical rept.,


Corporate Author : PSYCHIATRIC UNIVERSITY CLINIC BERN (SWITZERLAND) BRAIN RESEARCH INST


Personal Author(s) : Saul,Alan B ; Daniels,J D


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA175539


Report Date : 12 Dec 1986


Pagination or Media Count : 51


Abstract : Observations of developmental plasticity in the visual cortex of cats have inspired a number of theoretical models. These models attempt to mimic the development of response specificity. We review the assumptions upon which one can build models of the visual cortex. The anatomical layout usually consists of excitatory afferents from the lateral geniculate nucleus with intracortical inhibition among a population of cells. The degrees of convergence of the afference and divergence of the inhibition are some of the more important considerations which distinguish different models. Synaptic modifications rules lie at the heart of these theories. Modification is usually of the Hebbiam type with synaptic strengths changing as some function of the product of pre-and postsynaptic activity. A successful model not only alters synapses to generate specificity in single units, but simultaneously produces a cortical network which is stable and which mimics the behavior of experimental population.


Descriptors :   *VISUAL CORTEX , *ANATOMICAL MODELS , LINE OF SIGHT , SIMULATION , STIMULATION(PHYSIOLOGY) , MODELS , NETWORKS , MODIFICATION , THEORY , STRENGTH(GENERAL) , PLASTIC PROPERTIES , NERVE CELLS , VISUAL PERCEPTION , INHIBITION , SYNAPSE , NUCLEI , CEREBRAL CORTEX , CATS


Subject Categories : Anatomy and Physiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE