Fig. 1: Experimental paradigm, electrode implantation and behavioural results.
From: Representational dynamics during extinction of fear memories in the human brain
a, Experimental design. Top: contingencies of consistently threatening CS++ cues (red), consistently safe CS−− cues (green) and cues with changing contingencies (yellow) across the three experimental phases (acquisition, extinction and test). Cues were presented together with a set of context videos that were unrelated to the contingency in a given trial and that changed between phases (ABC paradigm). Bottom: trial structure. Contexts were presented first but remained on screen during CS presentation. The US consisted of either a neutral face (CS− trials) or a fearful face paired with a loud scream (CS+ trials). Participants rated the perceived cue contingencies on each trial. The cartoon faces shown are for illustrative purposes only and do not depict the actual stimuli used in the experiment. b, Electrode implantation. Selected contacts across our group of participants are overlaid on an average brain surface in MNI coordinates. Neocortical regions of interest selected for analysis included electrodes implanted bilaterally in temporal (blue), prefrontal (red) and orbitofrontal (green) cortices. c, Electrode locations in the amygdala (red) and the hippocampus (blue). d, Behavioural performance. Wilcoxon signed-rank tests were conducted at every trial position to investigate the progressive learning of task contingencies across experimental phases. Regions where significant effects were observed after correction for multiple comparisons are indicated at the bottom of the figure (cluster-based permutation statistics with 1,000 permutations; grey: CS+− vs CS−−; brown: CS++ vs CS−−; orange: CS+− vs CS++). Shaded lines depict group average ratings at each trial position ±s.e.m.
