Fig. 7.
Spike rate information content is increased by the phase of low and high frequency LFPs. a Raster plot of the BT unit shown in Fig. 2c (in response to seq4), in which spikes are color-coded according to the phase of 4–8 Hz LFPs. Note the bin color scheme in the panel. b Information content of the phase-of-fire code (Irate_phase) vs. the rate code (Irate), for each neuronal group (ST, BT, and NT), in three different LFP bands: a low frequency band (4–8 Hz, or theta), a middle frequency band (32–42 Hz), and a high frequency band (62–72 Hz). Comparisons are performed for each natural sequence tested, showing that Irate_phase was always significantly higher than Irate (FDR-corrected Wilcoxon signed-rank tests, pcorr ≤ 0.0037), also in the highest frequency band considered, 62–72 Hz. c Comparisons between Irate_phase obtained using low-frequency LFPs (4–8 Hz), vs. Irate_phase using high-frequency oscillations (62–72 Hz), for each neuronal group, in every call tested. Irate_phase calculated with 62–72 Hz LFPs was either significantly higher than Irate_phase computed with 4–8 Hz LFPs (FDR-corrected Wilcoxon signed-rank tests, pcorr ≤ 0.026), or at least not significantly different (pcorr > 0.077). (*pcorr < 0.05; **pcorr < 0.01; ***pcorr < 0.001)