Fig. 3: FRs and SFC of category neurons in MTL.
From: Control of working memory by phase–amplitude coupling of human hippocampal neurons
a, Example hippocampal category neuron. The preferred category of this neuron was ‘animals’. Pic., picture. b, Category neurons (n = 270) remained active (preferred (pref.) versus baseline (bsl), P = 0.0001; non-preferred (non-pref.), P = 0.0001) and retained their selectivity during the maintenance period, with FRs higher for preferred compared with non-preferred categories (P = 0.001). FRs are shown as the percentage change compared with the baseline (−0.9 to −0.3 s before picture 1 onset). c, FRs of category neurons were higher in load 1 compared with load 3 trials with their preferred category held in WM (n = 270, P = 0.004) during the maintenance period. d, Category neurons fired more in correct compared with incorrect trials (n = 246, P = 0.02). e, SFC between spikes and LFPs from the same area. The slice (https://osf.io/r2hvk/) was obtained under a Creative Commons licence CC BY 4.0. f, Paired with PAC channels, hippocampal category neurons were more strongly phase-locked to local gamma LFPs with the preferred category held in WM (n = 151 combinations; P = 0.004). Differences were not significant in the amygdala (n = 423) or non-PAC channels (Extended Data Fig. 5e). Statistical analysis was performed using two-sided cluster-based permutation t-tests. g, Gamma (70–140 Hz) SFC for hippocampal category neurons was stronger for preferred versus non-preferred trials in both load conditions (main effect preference, F1,150 = 16.23, P = 0.0001; load 1, P = 0.003; load 3, P = 0.004). No main effect of load (P = 0.25) or interaction (P = 0.33) was found. Each dot is a neuron–LFP channel pair (n = 151). h, TG-PAC was positively correlated with the FR of category neurons in the hippocampus (n = 151, P = 0.017, mixed-effects GLM), but not in the amygdala (n = 423, P = 0.45). The GLM results are shown in Supplementary Table 3. For b–d,g, statistical analysis was performed using two-sided permutation-based t-tests (b–d, lower brackets in g) and F-tests (top bracket in g). For a–d,f–h, data are mean ± s.e.m. (coloured areas in a,f); **P < 0.01.
