How the Dorsolateral Prefrontal Cortex Controls Affective Processing in Absence of Visual Awareness – Insights From a Combined EEG-rTMS Study

Abstract

The dorsolateral prefrontal cortex (DLPFC) plays a key role in the modulation of affective processing. However, its specific role in the regulation of neurocognitive processes underlying the interplay of affective perception and visual awareness has remained largely unclear. Using a mixed factorial design, this study investigated effects of inhibitory continuous theta-burst stimulation (cTBS) of the right DLPFC (rDLPFC) compared to an Active Control condition on behavioral (N = 48) and electroencephalographic (N = 38) correlates of affective processing in healthy Chinese participants. Event-related potentials (ERPs) in response to passively viewed subliminal and supraliminal negative and neutral natural scenes were recorded before and after cTBS application. We applied minimum-norm approaches to estimate the corresponding neuronal sources. On a behavioral level, we found evidence for reduced emotional interference by, and less negative and aroused ratings of negative supraliminal stimuli following rDLPFC inhibition. We found no evidence for stimulation effects on self-reported mood or the behavioral discrimination of subliminal stimuli. On a neurophysiological level, rDLPFC inhibition relatively enhanced occipito-parietal brain activity for both subliminal and supraliminal negative compared to neutral images (112–268 ms; 320–380 ms). The early onset and localization of these effects suggests that rDLPFC inhibition boosts automatic processes of “emotional attention” independently of visual awareness. Further, our study reveals the first available evidence for a differential influence of rDLPFC inhibition on subliminal versus supraliminal neural emotion processing. Explicitly, our findings indicate that rDLPFC inhibition selectively enhances late (292–360 ms) activity in response to supraliminal negative images. We tentatively suggest that this differential frontal activity likely reflects enhanced awareness-dependent down-regulation of negative scene processing, eventually leading to facilitated disengagement from and less negative and aroused evaluations of negative supraliminal stimuli.

Altered processing of social emotions in individuals with autistic traits

“…In agreement with prior ERP studies [34,70], the LNC amplitudes in Experiment 2 were modulated by "emotion", with positive and negative audio recordings eliciting larger amplitudes in the LNC time window than neutral audio recordings. As LNC over the posterior parietal cortical area is relevant to the conscious cognition of emotional stimuli [65], and LNC amplitudes are positively correlated with the evaluation of the subjective emotional valence of emotional stimuli [66], it appears that more mental processing resources were recruited for evaluation of positive and negative audio recordings as compared to neutral audio recordings.…”

Altered Processing of Social Emotions in Individuals With Autistic Traits

“…In agreement with prior ERP studies (Cheng et al, 2017;Keuper et al, 2018), the LNC amplitudes in Experiment 2 were modulated by "emotion, " with positive and negative audio recordings eliciting larger amplitudes in the LNC time window than neutral audio recordings. As LNC over the posterior parietal cortical area is relevant to the conscious cognition of emotional stimuli (Leventon et al, 2014), and LNC amplitudes are positively correlated with the evaluation of the subjective emotional valence of emotional stimuli (Suo et al, 2017), it appears that more mental processing resources were recruited for evaluation of positive and negative audio recordings as compared to neutral audio recordings.…”

Proceedings of the 2021 ISNR Annual Conference (Virtual): Keynote and Plenary Presentations

“…Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for medication resistant depression (Boes et al, 2018;Trapp et al, 2020). Numerous studies have investigated the neurophysiological, neuroanatomical, and functional connectivity effects relative to rTMS (Bailey et al, 2019;Ge et al, 2020;Keuper et al, 2018;Noda et al, 2017;Song et al, 2019;Wu et al, 2020). The typical target for rTMS is the left dorsolateral prefrontal cortex (DLPFC) with effects seen in cortical thickness in rostral anterior cingulate cortex (rACC) (Boes et al, 2018;Trapp et al, 2020).…”