Modulation of Emotion Perception via Amygdala Stimulation in Humans

• Published in: Frontiers in neuroscience Vol. 15; p. 795318
• Main Authors: Bujarski, Krzysztof A., Song, Yinchen, Xie, Tiankang, Leeds, Zachary, Kolankiewicz, Sophia I., Wozniak, Gabriella H., Guillory, Sean, Aronson, Joshua P., Chang, Luke, Jobst, Barbara C.
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Research Foundation 09.02.2022; Frontiers Media S.A
• Subjects: affective valence; Amygdala; arousal; brain stimulation; Deep brain stimulation; Electrical stimulation of the brain; Electrical stimuli; Electrodes; emotion perception; Emotions; Environmental effects; Epilepsy; ESB; Event-related potentials; Human subjects; Mental disorders; Neural networks; Neuromodulation; Neuroscience; Patients; Portable computers; brain stimulation; emotion perception; affective valence; amygdala; arousal
• ISSN: 1662-453X; 1662-4548; 1662-453X
• DOI: 10.3389/fnins.2021.795318

Multiple lines of evidence show that the human amygdala is part of a neural network important for perception of emotion from environmental stimuli, including for processing of intrinsic attractiveness/"goodness" or averseness/"badness," i.e., affective valence. With this in mind, we investigated the effect of electrical brain stimulation of the human amygdala on perception of affective valence of images taken from the International Affective Picture Set (IAPS). Using intracranial electrodes in patients with epilepsy, we first obtained event-related potentials (ERPs) in eight patients as they viewed IAPS images of varying affective valence. Next, in a further cohort of 10 patients (five female and five male), we measured the effect of 50 Hz electrical stimulation of the left amygdala on perception of affective valence from IAPS images. We recorded distinct ERPs from the left amygdala and found significant differences in the responses between positively and negatively valenced stimuli ( = 0.002), and between neutral and negatively valenced stimuli ( = 0.017) 300-500 ms after stimulus onset. Next, we found that amygdala stimulation did not significantly affect how patients perceived valence for neutral images ( = 0.58), whereas stimulation induced patients to report both positively ( = 0.05) and negatively (< 0.01) valenced images as more neutral. These results render further evidence that the left amygdala participates in a neural network for perception of emotion from environmental stimuli. These findings support the idea that electrical stimulation disrupts this network and leads to partial disruption of perception of emotion. Harnessing this effect may have clinical implications in treatment of certain neuropsychiatric disorders using deep brain stimulation (DBS) and neuromodulation.