Single-Trial Phase Precession in the Hippocampus

  • Schmidt R
  • Diba K
  • Leibold C
 et al. 
  • 198


    Mendeley users who have this article in their library.
  • 53


    Citations of this article.


During the crossing of the place field of a pyramidal cell in the rat hippocampus, the firing phase of the cell decreases with respect to the local theta rhythm. This phase precession is usually studied on the basis of data in which many place field traversals are pooled together. Here we study properties of phase precession in single trials. We found that single-trial and pooled-trial phase precession were different with respect to phase-position correlation, phase-time correlation, and phase range. Whereas pooled-trial phase precession may span 360 degrees , the most frequent single-trial phase range was only approximately 180 degrees. In pooled trials, the correlation between phase and position (r = -0.58) was stronger than the correlation between phase and time (r = -0.27), whereas in single trials these correlations (r = -0.61 for both) were not significantly different. Next, we demonstrated that phase precession exhibited a large trial-to-trial variability. Overall, only a small fraction of the trial-to-trial variability in measures of phase precession (e.g., slope or offset) could be explained by other single-trial properties (such as running speed or firing rate), whereas the larger part of the variability remains to be explained. Finally, we found that surrogate single trials, created by randomly drawing spikes from the pooled data, are not equivalent to experimental single trials: pooling over trials therefore changes basic measures of phase precession. These findings indicate that single trials may be better suited for encoding temporally structured events than is suggested by the pooled data.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • R. Schmidt

  • K. Diba

  • C. Leibold

  • D. Schmitz

  • G. Buzsaki

  • R. Kempter

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free