Extended Data Fig. 7: SFC and theta phase shift analysis for PAC neurons.

(a) PAC neurons were not selective for category in hippocampus (left) and amygdala (right). Even during encoding, category could not be efficiently decoded from FR of “PAC only” neurons (all other p = 0.001, right-sided permutation test). Decoding performance is shown as mean ± s.d. across 1,000 decoding repetitions. Black horizontal lines indicate mean decoding of 1,000 randomly shuffled category labels (chance level). Decoding was performed for pseudo-populations of category or PAC neurons, respectively. (b,c) Theta and gamma SFC between PAC neurons and local LFP recordings did not differ as a function of load in (b) the hippocampus (theta: t(78) = −1.54, p = 0.13; gamma: t(78) = −1.12, p = 0.27, n = 79), or (c) the amygdala (theta: t(162) = −0.71, p = 0.47; gamma: t(162) = 0.76, p = 0.45, n = 163). Theta and gamma SFC, however, were both significantly stronger than shuffled surrogates in both areas (all p = 0.0001). Each dot is a neuron-channel combination. In (a,b), we performed two-sided permutation-based t-tests and centre values denote mean ± s.e.m. (d) The preferred theta phase of PAC neurons did not differ significantly as a function of load in both areas of the MTL. Red bars show the mean difference in preferred theta phases between load 1 and 3 across all PAC neurons. *** p < 0.001; ns = not significant.