Why the simplest notion of neocortex as an autoassociative memory would not work

Abstract

We discuss the idea that long range cortico-cortical connections might be the substrate for an autoassociative memory mechanism, whereby features processed locally could be linked together over large portions of neocortex. The simplest version of this idea is shown to be implausibly inadequate in terms of storage capacity; although up to a fraction of a bit could be stored on each synapse, the number of global activity patterns that could be stored and individually retrieved would scale not with the size of the network but, effectively, only with the number of modifiable connections per cell.