The amygdala 30–45 Hz aperiodic exponent did not differ between aversive and neutral film blocks in 9 epilepsy patients

We tested whether the 30–45 Hz aperiodic exponent of amygdala stereo-electroencephalography (SEEG), a range linked in earlier work to excitation/inhibition balance, differed between aversive fearful-face and neutral landscape film blocks. We analyzed 9 patients and 14 amygdalae from OpenNeuro ds003374 version 1.1.1: 8 aversive and 9 neutral blocks of 24 s per patient. A plan was written and hashed before statistics were computed. The primary measure was the bipolar amygdala exponent, estimated as the negative least-squares slope of log power on log frequency from 30 to 45 Hz using Welch spectra with 1-s Hann segments and 50% overlap. The mean patient-level aversive-minus-neutral difference was −0.004 (95% bootstrap CI −0.121 to +0.116; 4 of 9 patients positive; exact sign-flip p = 0.95). The secondary monopolar difference was +0.108 (95% CI −0.013 to +0.241; p = 0.16; Holm-adjusted p = 0.32). No patient had a significant within-patient block-label effect; the Fisher-combined p was 0.82. The group result agrees with an earlier 3–45 Hz slope null. In this sample, the 30–45 Hz amygdala exponent did not show an aversive-content effect at group or patient level. The sample included only 9 patients, all with epilepsy; block order was fixed, and a linear fit was used without a knee or peak model.

amygdala · stereo-electroencephalography · aperiodic exponent · aversive stimuli · neutral stimuli · excitation/inhibition balance · OpenNeuro · sign-flip test