A multi-state model of cortical memory

A fundamental property of cortical pathways is the ability to retain information beyond time-delimited environmental events. Here, we propose that the neural connectivity between different regions of cortex directly contributes to the preservation of memory traces. A structural network of macaque cortex was obtained from the CoCoMac database. A computational model was then employed to simulate the flow of information between regions of interest (ROIs). This model assigned discrete states to each of 47 ROIs, and allowed exchanges between ROIs as well as random memory decay over time. The rate at which memory decayed over time depended on the network topology; it was found to be markedly less in primate cortex than in a random connectivity that preserved the experimental degree distribution. These results suggest that evolutionary constraints may promote a large-scale cortical anatomy that is optimized for the continuity of memory in time.