Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 14, 2009 | public
Journal Article

Beyond Poisson : increased spike-time regularity across primate parietal dortex

Abstract

Cortical areas differ in their patterns of connectivity, cellular composition, and functional architecture. Spike trains, on the other hand, are commonly assumedto follow similarly irregulardynamics across neocortex. We examined spike-time statistics in four parietal areas using a method that accounts for nonstationarities in firing rate. We found that, whereas neurons in visual areas fire irregularly, many cells in association and motor-like parietal regions show increasingly regular spike trains by comparison. Regularity was evident both in the shape of interspike interval distributions and in spike-count variability across trials. Thus, Poisson-like randomness is not a universal feature of neocortex. Rather, many parietal cells have reduced trial-to-trial variability in spike counts that could provide for more reliable firing-rate signals. These results suggest that spiking dynamics may play different roles in different cortical areas and should not be assumed to arise from fundamentally irreducible noise sources.

Additional Information

© 2009 Elsevier Inc. Accepted March 19, 2009; published May 13, 2009. We thank J.H.R. Maunsell, C. Padoa-Schioppa, R. Maimon, and P. Weir for helpful comments on the manuscript and discussions. K. Irwin, T. Lafratta, M. LaFratta, J. LeBlanc, and D. Averbuch provided technical assistance. This work was supported by NEI EY12106 and the McKnight Endowment Fund for Neuroscience and an NEI Vision Core Grant, EY12196.

Additional details

Created:
August 20, 2023
Modified:
October 18, 2023