On the Storage Capacity of the Hopfield Model with Biased Patterns

Abstract

We introduce a form of the Hopfield model that is able to store an increasing number of biased i.i.d. patterns (it is well known that the standard Hopfield model fails to work properly in this context). We show that this new form of the Hopfield model with N neurons can store (N)/(/spl gamma/ log N) or /spl alpha/N biased patterns (depending on which notion of storage is used). The quantity /spl gamma/ increases with an increasing bias of the patterns, while /spl alpha/ decreases when the bias gets large.