The first cortically based associative circuits integrated olfactory, motivational, and motor information. Many of the neural dynamics present in these evolutionarily ancient, olfactory-motor circuits, such as the broadband frequency, phase, and amplitude modulations seen during recognition of a rewarded olfactory stimulus, are also found in isocortical circuits. These results suggest that mechanisms permitting olfactory associative processing formed the basis for evolutionarily more recent large-scale couplings involving isocortical areas.

Cognitive mechanisms are based in organisms’biology, and results from biological studies suggest that there is unlikely to be a single mechanism for reorienting or for combining information across modules or domains. Rather, there are likely to be multiple, partly overlapping systems for accomplishing nearly all cognitive and behavioral goals, as is the case for biological mechanisms more generally.