Patent US 5,485,546

An apparatus for categorizing objects employs a neural network having a plurality of cells each having memory for storing a state variable, and a plurality of synaptic junctions connecting cells of the network and having memory for storing a synaptic strength variable. A computer is used to modify the synaptic strength variable in accordance with a heterocellular synaptic modification rule. That modification rule includes both the passage of time and the values of the state variables of each cell and of those other cells having specific spatial locations with respect to the cell in three dimensional space.