Recollection and imagination in a functional model of visual cortex

Abstract

In \cite{kupper06-CNS} we have presented a model of signal flow infunctional cortical columns, across the six cortical layers and betweenseveral cortical areas. We showed how the columnar subsystems interactto predict and recognize stimuli in terms of locally stored knowledge.In this model, columnar communication integrated bottom-up signalswith internally generated top-down signals to describe the stimulusconsistently across all cortical areas. Here we extend this modelto demonstrate that the same setup of intercommunicating columnscan use the stored knowledge to integrate a pre-activation on thehighest level with the bottom-up recognition process. % Given onlycoarse or invariant top-down activation, the model can (i) guideand support the recognition of noisy or ambiguous stimuli, and (ii)recall known objects, at the highest level of detail, by creatingspecific neural activations across all cortical areas. % The secondprocess corresponds to recollection or mental imagery, the processin which the brain internally creates a percept without a physicalstimulus.