Fig. 5
From: Encoding of long-term associations through neural unitization in the human medial temporal lobe
Phase locking analysis for individual and multiple responses. a Exemplary unit recorded in the left hippocampus exhibiting a response to the picture of Alastair Cook, former captain of the English cricket team. Same conventions as in Fig. 3a. The spike response latency is 439 ms, with the LFP onset occurring 130 ms earlier. Circular histograms of the phase at the spike times during baseline (green, left) and response (blue, right) periods (marked with green and blue shaded areas, respectively). Red lines represent the mean phase vector. Spikes during the baseline period are not significantly phase locked (PLI = 0.05, p = 0.82), in contrast to those in the response period (PLI = 0.44, p = 1.6 × 10−3). Due to copyright issues, the image presented here (cropped from “Alastair cook bowl” by Blnguyen, licensed under CC BY-SA 3.0) is similar to the one actually presented to the subject. b PLI for the significant phase-locked responses (actual vs. mean of the surrogate distribution). The mean shuffled values were significantly smaller than the original ones (n = 82, one-sided paired sign test, p ~ 10−11), showing a relation between the spike times and the instantaneous LFP phases at the single trial level. c Distribution of mean phase difference for the responsive and surrogate pairs. The difference in the response-eliciting pairs was significantly smaller than the one on a representative distribution of surrogate pairs (n = 44, one-sided rank-sum test, p ~ 10−4). Vertical arrows denote the median of the distributions
