Fig. 2: V1 populations spontaneously extract temporal information.

a Neural activity in early trials for one session. (top panels) Spiking activity for multiple laser-responsive neurons (each horizontal band) for first 20 trials with (left) and without (right) laser stimulation. (bottom panels) Average population firing rates for the first 20 trials. Light blue stripes represent the actual duration of the laser pulses (left), or the times at which the laser pulses would appear, aligned with the cue onset (right). Red rectangles represent statistically significant firing rate peaks during the blank condition temporally aligned with the time of the laser pulses (P < 0.05, Wilcoxon signed rank test). (lower panel) Zoom-in of a relevant time period in blank trials equivalent to the duration of the first 4 laser pulses. b Neural activity in late (last 20) trials for the same session. All panels are the same as in (a). The number of significant peaks in the blank late trials increases relative to early trials. c Mean population firing rate (n = 35 sessions) as a function of time since cue onset for laser (blue) and blank (red) late trials and for the shuffled condition (orange; spike times were shuffled in each trial). d Description of laser-blank correlation coefficient calculation for the early and late trials in the same session. Light blue stripes are the same as in (a). Only the time duration of the first 4 laser pulses is shown. e Correlation coefficient between the average firing rates during laser and blank trials (groups of 10 trials) for two sessions. The lines show the second order polynomial fit. f Average correlation coefficient between the mean firing rates during laser and blank trials over all sessions (blue) compared with the same measure but with shuffled spikes (orange) in blank trials (n = 40). Error envelopes represent s.e.m. g Correlation coefficient for early trials (magenta), late trials (blue), and shuffled spike trains late trials (orange). Each circle represents one session, solid rectangles are averages over sessions (n = 40; P = 3.85e-08, P = 7.05e-08, two-sided Wilcoxon signed rank test).