Associative memory with high information content

An extension of Hopfield's model with adaptive threshold and inhibitory interactions yields a network capable of nearly optimal storage of patterns of low activity. A replica symmetric solution of the mean-field equations is presented for the noise-free case. The following properties are demonstrated: For a low level of activity a the storage capacity increases as - (a lna) ^-1; up to 0. 38 bits per synapse can be stored; spurious states can be suppressed; the network is not opinionated, i. e. , it can categorize inputs as not similar enough to patterns stored.