FUNCTIONAL IMPACT OF CEREBRAL CONNECTIONS

Cerebral networks are complex sets of connections that resemble a ladd er-like web of multiple parallel feedforward, lateral, and feedback co nnections. This static anatomical description has been pivotal in guid ing our understanding of signal processing within cerebral networks. H owever, measures on both magnitude and functional significance of conn ections are extremely limited. Here, we compare the anatomically defin ed strengths of a set of cerebral pathways emerging from the visual mi ddle suprasylvian (MS) cortex of the cat with measures of the function al impact the same region has over distant sites. These functional mea sures were obtained by analyzing the local and distant effects of MS c ooling deactivation on deoxyglucose uptake. Relative to major efferent projections from MS cortex that have a strong influence, projections to early visual processing stages have weaker functional influences th an predicted fi om the anatomy. For higher processing stages, the conv erse holds: projections from MS cortex have stronger functional influe nce than predicted from the anatomy. We conclude that these and future functional measures, obtained using the same combination of technique s, will furnish fundamental, new information that complements and exte nds current models of static cerebral net works, and lead to more real istic models of cerebral network function and component interactions.