Outline of hetero-associative memory functions we studied.

Phase patterns of presynaptic neurons are associated with those of postsynaptic neurons in the hetero-associative memory. In the storage process, pairs of pre- and postsynaptic phase patterns, and (), are embedded by modifying synaptic weights in accordance with an STDP learning rule. In the retrieval process, when presented with a phase pattern of presynaptic neurons which resembles the μ-th memory key pattern that is temporally reversed and/or stretched to times its original timescale, (), the postsynaptic neurons recall a phase pattern which resembles the associated memory output pattern that is temporally reversed and/or stretched to times its original timescale, .