Poster presented at CNS*99, Pittsburgh, Pennsylvania, July 18-22, 1999. Dynamics in LIP Spike Train Coherence J. S. Pezaris, M. Sahani, R. A. Andersen Computation and Neural Systems Sloan Center for Theoretical Neurobiology California Institute of Technology, Pasadena, CA 91125, U.S.A. Abstract The dynamics of cell-to-cell interactions as measured by the coherence between spike trains can help elucidate local circuitry and phases of operation for networks of neurons. We compute the coherence between pairs of spike trains collected from macaque area LIP during a memory saccade task. Significant coherence is found for frequencies below 50Hz, and time lags less than +-10ms. The mean coherence, as examined in both the time and frequency domains for a sliding window, undergoes changes which correspond to behavioral events, but are not necessarily linked to the mean firing rates of the recorded cells. Our results suggest that the maintenance of memory activity is done through a different mechanism than sensory response and saccade generation. Poster (PostScript, 231 kB gzip compressed) Preprint (PostScript, 414 kB uncompressed) John Pezaris, Harvard Medical School, 220 Longwood Ave, Boston, MA 02115, USA pz (at) hms (dot) harvard (dot) edu 28 July 1999.