Figure 1.

Experimental paradigm (A). A NP and P image are found that the neuron does not and does respond to. These are then combined and presented in a C stimulus. Both P and NP images are presented again after this learning phase. Network connectivity (B). The architecture of the network (Bi) shows how a group of NC neurons and a group of hippocampal (Hip) neurons receive input from a 10 and 4 Hz tonic wave, respectively, and both groups receive (background) noise from Poisson distributed spikes. Two subgroups of NC neurons receive input from higher level areas that represent the P and NP image. Each subgroup of NC and Hip neurons has reciprocal connectivity between themselves, 25% for NC and 40% for Hip. Hippocampal neurons also receive an ADP function. Hippocampal neurons are interconnected (i.e., not just within subgroups), again with 40% connectivity, and STDP is enabled with a theta phase-dependent learning rate (Bii).