Spike train coherence in macaque parietal cortex during a memory saccade task

The dynamics of cell-to-cell interactions as measured by the coherence betw een spike trains can help elucidate local circuitry and phases of operation for networks of neurons. We compute the coherence between pairs of spike t rains collected from macaque area LIP during a memory saccade task. Signifi cant coherence is found for frequencies below 50 Hz, and time lags less tha n +/- 10 ms. The mean coherence, as examined in both the time and frequency domains for a sliding window, undergoes changes which correspond to behavi oral events, but are not necessarily linked to the mean firing rates of the recorded cells. Our results suggest that the maintenance of memory activit y is done through a different mechanism than sensory response and saccade g eneration. (C) 2000 Elsevier Science B.V. All rights reserved.