1. A lateral neural network structure comprising: a layer having a plurality of neurons, each of said plurality of neurons having at least two physically separate optical sub-units, one constructed for broadcasting lateral inhibitory signals and one constructed for broadcasting lateral excitatory signals; and means for optically coupling said sub-units in a bi-directional manner for broadcasting both inhibitory and excitatory lateral signals; wherein sub-units constructed for broadcasting lateral inhibitory signals are located for reception of lateral excitatory signals and reception of external inhibitory inputs; and sub-units constructed for broadcasting lateral excitatory are located for reception of lateral inhibitory signals and reception of external excitatory inputs.