Fig. 3: Prevalence of theta phase precession across different task stages.
From: Theta phase precession supports memory formation and retrieval of naturalistic experience in humans
a, Example hippocampal phase precession neuron during encoding. The spiking phases relative to local theta (y axis) are plotted as a function of time in unwrapped theta phase (Methods). Each dot shows one spike within three theta cycles (x axis) relative to boundaries. The orange line indicates the fitted correlation between neuronal spiking phase and time in unwrapped theta phase. b–d, Distribution of correlation coefficients for all MTL neurons demonstrating phase precession during encoding (b, orange), scene recognition (c, blue) or time discrimination (d, green). The distribution of correlation coefficients for neurons without phase precession is plotted in grey. Note that strong phase precession is indicated by negative correlation coefficients. e, Comparison of phase precession strength during encoding for the phase precession neurons in b (n = 68). Plotted are circular–linear correlation coefficients computed using spikes within three theta cycles before (Pre-Boundary) and after (Post-Boundary) boundaries, after clip onsets (Post-ClipOnset) and after clip offsets (Post-ClipOffset) in boundary clips, as well as before (Pre-NoBoundary) and after (Post-NoBoundary) the midpoint in no-boundary clips. ***P = 4 × 10−5 (two-tailed t-test against zero); NS, not significant. f,g, Comparison of phase precession strength during scene recognition (f) or time discrimination (g) for the phase precession neurons in c (n = 51) and d (n = 89), respectively. Plotted are circular–linear correlation coefficients computed using spikes within three theta cycles before (Pre-ImageOnset) and after image onsets (Post-ImageOnset), after image offsets (Post-ImageOffset) and after making a memory choice (Post-ButtonPress). The asterisk and horizontal line denote the mean and median of the data, respectively. The shaded violin shape represents the data distribution, with the lower end indicating the 1st percentile (minima) and the top end indicating the 99th percentile (maxima). The top edge and bottom edge of the shaded rectangle represent the mean ± s.d. and mean − s.d., respectively. The top edge and bottom edge of the shaded hourglass represent the 75th and 25th percentiles, respectively. ***P = 3 × 10−8 in f and ***P = 7 × 10−8 in g, two-tailed t-test against zero.
