ABSTRACT
It has been hypothesized (Lynch 1986; Aboitiz et al. 2002; Montagnini and Treves 2003) that the mammalian cortex initially evolved as an associative structure, allowing features of the sensory world extracted by more peripheral circuits to be merged both within and between sensory modalities into objects capable of driving behavior. Associative cortical circuits generally have broadly distributed, overlapping inputs, allowing convergence of different pieces of information. This is in contrast to classic topographic, hierarchical cortical circuits, where information flow is more restricted to narrow, specialized channels, with much less cross-talk between disparate inputs.
