Spatial Feature Extraction by Spike Timing Dependent Synaptic Modification

Abstract

AbstractSpike timing dependent synaptic plasticity (STDP) is found in various areas of the brain, visual cortex, hippocampus and hindbrain of electric fish, etc. The synaptic modification by STDP depends on time difference between pre- and postsynaptic firing time. If presynaptic neuron fires earlier than postsynaptic neuron dose, synaptic weight is strengthened. If postsynaptic neuron fires earlier than presynaptic neuron dose, synaptic weight is weakened. This learning rule is one example of various rules (hippocampal type). The learning rule of electric fish type is reversed to the rule of hippocampal type. Changes of synaptic efficiency precisely depend on timing of pre- and postsynaptic spikes under STDP. Because of this precise dependence, it is thought that STDP plays the important role in temporal processing. Temporal processing by STDP is well known. However, the role of STDP in spatial processing is not enough understood. In present study, we propose two type spatial filter by STDP on interconnected network. One is high-pass filter when the learning rule is hippocampal type. Another is low-pass filter when the learning rule is electric fish type. We show that synaptic modification based on STDP may play important role in spatial processing.