Directional Influence between the Human Amygdala and Orbitofrontal Cortex at the Time of Decision-Making
(A, B, C) Spectral coherence, computed on the interval −1 s to +2 s from stimulus onset and 5 Hz to 40 Hz for each subject. The spectral density used to compute time-frequency coherence was calculated using a sliding 300 ms window and a multitaper technique with a step size of 10 ms. Spectral coherence is only pairwise and is not conditioned on all other contact time series. (D, E, F) A one-sided cluster-based permutation test was performed for each subject by random rearrangement of trials for each contact. The cluster suprathreshold maximum was identified over a (time, frequency) grid composed of 280 ms by 2.5 Hz tiles for a total of 154 frequency-time clusters. The contact-pair direction was analyzed between each of the amygdala-OFC pairs and then aggregated over all of the contact pairs for each subject. The FWER was controlled at.01, and the corresponding critical values were used to mask any clusters that fell within the central region determined by the single null permutation distribution and consequently non-significant.