Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published September 2021 | public
Journal Article

Amygdaloid theta-band power increases during conflict processing in humans


The amygdala is a medial temporal lobe structure known to be involved in processing emotional conflict. However, its role in processing non-emotional conflict is not well understood. Previous studies have utilized the Stroop Task to examine brain modulation of humans under the color-word conflict scenario, which is non-emotional conflict processing, and found hippocampal theta-band (4–7 Hz) modulation. This study aims to survey amygdaloid theta power changes during non-emotional conflict processing using intracranial depth electrodes in nine epileptic patients (3 female; age 20–62). All patients were asked to perform a modified Stroop task. During task performance, local field potential (LFP) data was recorded from macro contacts sampled at 2 K Hz and used for analysis. Mean theta power change from baseline was compared between the incongruent and congruent task condition groups using a paired sample t-test. Seven patients were available for analysis after artifact exclusion. In five out of seven patients, statistically significant increases in theta-band power from baseline were noted during the incongruent task condition (paired sample t-test p < 0.001), including one patient exhibiting theta power increases in both task conditions. Average response time was 1.07 s (failure trials) and 1.04 s (success trials). No speed-accuracy tradeoff was noted in this analysis. These findings indicate that human amygdaloid theta-band modulation may play a role in processing non-emotional conflict. It builds directly upon work suggesting that the amygdala processes emotional conflict and provides a neurophysiological mechanism for non-emotional conflict processing as well.

Additional Information

© 2021 Elsevier. Received 16 April 2021, Accepted 1 July 2021, Available online 14 July 2021. We wish to acknowledge the generous support of the National Center for Advancing Translational Science (NCATS) of the U.S. National Institutes of Health (KL2TR001854), the Tianqiao and Chrissy Chen Brain-Machine Interface Center at Caltech, the Meira and Shaul G. Massry Foundation, and the Taiwan-USC Postdoctoral Fellowship Program. The authors have no financial disclosures. The authors have no conflicts of interest to disclose. The highest level of ethical adherence was maintained with this manuscript. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional details

August 22, 2023
October 23, 2023