Is the hippocampus an autoassociator for general, non-spatial events?

Bruce L. McNaughton

(University of California, Irvine)

Date: Wednesday March 4, 2015

Description:

The location where rat hippocampal cells fire in the environment appears to be established primarily the path integration system, although exactly how is not well understood; however, the rates at which cells fire in their place fields appears to be driven by additional cues coming from the environment and/or internal state variables such as working memory and planning of future trajectories. The external (to the hippocampus) cues drive a process now called ‘rate remapping’, which can rapidly change the rates, but not the locations of place cell firing. Previously we obtained evidence that the spatial component exhibits evidence of attractor dynamics whereas the rate component does not. This creates problems for the theory of the hippocampus as a general autoassociator and for the theory that it can preserve in memory unique ‘index codes’ for the attributes of memories stored in distributed neocortical modules. I will discuss some new evidence and a somewhat more sophisticated conceptual model which seems to rescue the classic theories. Time permitting, I will also address some current issues surrounding the topic of pattern separation, another element of the classic theory.

Further Information:

This talk will not be posted at this time.




Created: Wednesday, March 4th, 2015