The 'module-concept' in cerebral cortex architecture.

An attempt is made to bring earlier circuit models of primary sensory cortical areas into better line with recent observations on (1) the distribution of excitatory feedback connexions in cortical tissue volume, (2) putative inhibitory interneurons and the distribution of inhibition in well defined space modules, and (3) the direct (monosynaptic) cortical target cells of the specific sensory afferents, and the modes of relay to secondary neurons. Even though the concept of cortical circuitry on larger 'integrative units' containing smaller modules (or fields) of specific (excitatory and inhibitory) neuronal actions, proposed in 1967 (ref. 34) and 1969 (ref. 35), had gross deficiencies in the light of newly emerging data, the basic idea of how to look at the functional organization of the cortical neuron network may still be useful as a conceptual framework for the functional interpretation of structural data.