TY - JOUR
T1 - Theta low-gamma phase amplitude coupling in the human orbitofrontal cortex increases during a conflict-processing task
AU - Chen, Kuang Hsuan
AU - Tang, Austin M.
AU - Gilbert, Zachary D.
AU - Martin Del Campo-Vera, Roberto
AU - Sebastian, Rinu
AU - Gogia, Angad S.
AU - Sundaram, Shivani
AU - Tabarsi, Emiliano
AU - Lee, Yelim
AU - Lee, Richard
AU - Nune, George
AU - Liu, Charles Y.
AU - Kellis, Spencer
AU - Lee, Brian
N1 - Funding Information:
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 Meira and Shaul G Massry Foundation, and the Taiwan-USC Postdoctoral Fellowship Program.
Funding Information:
This work was supported by the National Center for Advancing Translational Science (NCATS) of the U.S. National Institutes of Health (KL2TR001854), Tianqiao and Chrissy Chen Brain-Machine Interface Center at Caltech, the Meira and Shaul G Massry Foundation, and the Taiwan-USC Postdoctoral Fellowship Program.
Publisher Copyright:
© 2022 IOP Publishing Ltd.
PY - 2022/2
Y1 - 2022/2
N2 - Objective. The human orbitofrontal cortex (OFC) is involved in automatic response inhibition and conflict processing, but the mechanism of frequency-specific power changes that control these functions is unknown. Theta and gamma activity have been independently observed in the OFC during conflict processing, while theta-gamma interactions in other brain areas have been noted primarily in studies of memory. Within the OFC, it is possible that theta-gamma phase amplitude coupling (PAC) drives conflict processing. This study aims to characterize the coupled relationship between theta and gamma frequency bands in the OFC during conflict processing using a modified Stroop task. Approach. Eight epilepsy patients implanted with OFC stereotactic electroencephalography electrodes participated in a color-word modified Stroop task. PAC between theta phase and gamma amplitude was assessed to determine the timing and magnitude of neural oscillatory changes. Group analysis was conducted using a non-parametric cluster-permutation t-test on coherence values. Main results. Theta-low gamma (LG) PAC significantly increased in five out of eight patients during successful trials of the incongruent condition compared with the congruent condition. Significant increases in theta-LG PAC were most prominent during cue processing 200-800 ms after cue presentation. On group analysis, trial-averaged mean theta-LG PAC was statistically significantly greater in the incongruent condition compared to the congruent condition (p < 0.001, Cohen's d = 0.51). Significance. For the first time, we report that OFC theta phase and LG amplitude coupling increases during conflict resolution. Given the delayed onset after cue presentation, OFC theta-LG PAC may contribute to conflict processing after conflict detection and before motor response. This explanation follows the hypothesis that global theta waves modulate local gamma signals. Understanding this relationship within the OFC will help further elucidate the neural mechanisms of human conflict resolution.
AB - Objective. The human orbitofrontal cortex (OFC) is involved in automatic response inhibition and conflict processing, but the mechanism of frequency-specific power changes that control these functions is unknown. Theta and gamma activity have been independently observed in the OFC during conflict processing, while theta-gamma interactions in other brain areas have been noted primarily in studies of memory. Within the OFC, it is possible that theta-gamma phase amplitude coupling (PAC) drives conflict processing. This study aims to characterize the coupled relationship between theta and gamma frequency bands in the OFC during conflict processing using a modified Stroop task. Approach. Eight epilepsy patients implanted with OFC stereotactic electroencephalography electrodes participated in a color-word modified Stroop task. PAC between theta phase and gamma amplitude was assessed to determine the timing and magnitude of neural oscillatory changes. Group analysis was conducted using a non-parametric cluster-permutation t-test on coherence values. Main results. Theta-low gamma (LG) PAC significantly increased in five out of eight patients during successful trials of the incongruent condition compared with the congruent condition. Significant increases in theta-LG PAC were most prominent during cue processing 200-800 ms after cue presentation. On group analysis, trial-averaged mean theta-LG PAC was statistically significantly greater in the incongruent condition compared to the congruent condition (p < 0.001, Cohen's d = 0.51). Significance. For the first time, we report that OFC theta phase and LG amplitude coupling increases during conflict resolution. Given the delayed onset after cue presentation, OFC theta-LG PAC may contribute to conflict processing after conflict detection and before motor response. This explanation follows the hypothesis that global theta waves modulate local gamma signals. Understanding this relationship within the OFC will help further elucidate the neural mechanisms of human conflict resolution.
KW - conflict processing
KW - human
KW - local field potential
KW - orbitofrontal cortex
KW - phase-amplitude coupling
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U2 - 10.1088/1741-2552/ac4f9b
DO - 10.1088/1741-2552/ac4f9b
M3 - Article
C2 - 35086075
AN - SCOPUS:85124636578
SN - 1741-2560
VL - 19
JO - Journal of Neural Engineering
JF - Journal of Neural Engineering
IS - 1
M1 - 016026
ER -