Investigations on emergent spatio-temporal neural response characteristics in a small network model

Although the functional role synchronous oscillations may play has been investigated in depth, the underlying processes and spatio-temporal aspects that establish the synchrony are still not thoroughly understood. Experimental studies suggest the existence of two types of activity: stimulus locked and stimulus induced. While stimulus-locked oscillations are systematically dependent on the stimulus (they are phase-locked to stimulus transients), stimulus-induced activity patterns (occurring in the gamma-frequency range) show no such phase-locking. We propose a unifying approach which employs very generic connection structures. The above-mentioned two types of activity patterns with different temporal properties are observed as an emergent feature of the network structure. Our model demonstrates that stimulus-locked and stimulus-induced activity patterns are two distinct states of the same system. A transition from one state to the other is observed, and the influence of structural network parameters (e.g. connections strengths) on this behavior and its dependence on stimulus situations is investigated.