Fig. 4
Impact of inter-areal coherence on inter-laminar signal processing in TE. a Schematics for cascades of inter-areal and inter-laminar signal processing. b Diagram of spike-triggered average (STA) of the γ-power (STAγ). A36 spikes that were coherent with TE local field potentials (LFPs) at the channel showing maximum coherence were first extracted (shown in black ticks) from all spike trains. Then, a STA of γ activity envelope (green) was calculated. The γ activity envelope was selected at the TE channel showing maximum γ-power (in this example, in SG). See Methods for details. c Histograms of TE channels showing maximum γ-power. Gr granular layer. n = 56. See also Supplementary Figure 14. d Population STAγ with coherent spikes in cluster 1. e Power spectrum of STAγ (STAγ power) for each cluster (mean ± s.e.m.) during the cue period. STAγ power with coherent spikes and non-coherent spikes are shown separately. n = 19, 24, and 13 for clusters 1, 2, and 3, respectively. Bottom panels depict the STAγ power for datasets with maximum γ-power at infragranular layer (IG, left) and at the supragranular layer (SG, right). f The STAγ power for each cluster during the delay period. See also Supplementary Figure 15. g, h Error analysis of STAγ for each cluster during the cue period (g) and the delay period (h). Shown are the mean (±s.e.m.) values of difference in STAγ power between coherent and non-coherent spikes at the frequency range of 13−23 Hz (cue) and 5−18 Hz (delay). *, comparison with zero (*, P < 0.05; **, P < 0.01; ***, P < 0.001; paired t-test corrected for multiple comparisons). †, t-test corrected for multiple comparisons (†, P < 0.05, ††, P < 0.01, †††, P < 0.001). Note that the number of correct trials was reduced to be matched with that of error trials (see Methods)
