HYPERCOLUMNS OF GUINEA-PIG VISUAL-CORTEX - HETEROGENEITY AND MULTILEVEL ORGANIZATION OF TOPICAL PROJECTIONS

Spatial distribution of neural responses to spots, slits, and bars in the guinea pig visual cortex reveals hypercolumns like those in the br ain of higher mammals. The regular heterogeneities of topic projection s within and between hypercolumns (reflected in a distribution of foca l potentials in different cortical areas) suggest that the described c olumns are discrete cortical zones (or macromodules) about 0,6 mm in s ize. They consist of 7-10 on/off polar orientation micromodules about 0,2 mm in size. In turn, the latter also have the inner topical organi zation of their projections. Consequently, the described topical proje ctions have a multilevel hierarchical organization of accordance with different complicity of neural structures. Taking into account the kno wn polar structure of hypercolumns we think that it provides a possibi lity of comparison between the vectors of signals and polar structures . There are reasons to believe that this is a principle condition for signal recognition.