Differential Modulation of Effective Connectivity in the Brain’s Extended Face Processing System by Fearful and Sad Facial Expressions

Abstract

The processing of emotional facial expressions is underpinned by the integration of information from a distributed network of brain regions. Despite investigations into how different emotional expressions alter the functional relationships within this network, there remains limited research examining which regions drive these interactions. This study investigated effective connectivity during the processing of sad and fearful facial expressions to better understand how these stimuli differentially modulate emotional face processing circuitry. Ninety-eight healthy human adolescents and young adults, aged between 15 and 25 years, underwent an implicit emotional face processing fMRI task. Using dynamic causal modeling (DCM), we examined five brain regions implicated in face processing. These were restricted to the right hemisphere and included the occipital and fusiform face areas, amygdala, and dorsolateral prefrontal cortex (dlPFC) and ventromedial prefrontal cortex (vmPFC). Processing sad and fearful facial expressions were associated with greater positive connectivity from the amygdala to dlPFC. Only the processing of fearful facial expressions was associated with greater negative connectivity from the vmPFC to amygdala. Compared with processing sad faces, processing fearful faces was associated with significantly greater connectivity from the amygdala to dlPFC. No difference was found between the processing of these expressions and the connectivity from the vmPFC to amygdala. Overall, our findings indicate that connectivity from the amygdala and dlPFC appears to be responding to dimensional features which differ between these expressions, likely those relating to arousal. Further research is necessary to examine whether this relationship is also observable for positively valenced emotions.

Experimental evidence for a child‐to‐adolescent switch in human amygdala‐prefrontal cortex communication: A cross‐sectional pilot study

“…Importantly, the models are limited to unidirectional influence, and the present study cannot dissociate whether information flow in a specific connection is solely unidirectional or simply stronger in one of the directions. However, prior evidence suggests that studies of effective connectivity during human development can map changes in directed information flow (acyclic) associated with emotion regulation (Jamieson et al, 2021;Jiang et al, 2019;Kadosh et al, 2016), and we note that the discovery of an age-related switch in the dominance of information flow provides critical insight into frontoamygdala development regardless of whether that dominance reflects an underlying unidirectional or bidirectional connection. Though the sample size in the present pilot study is limited, the IMaGES approach is the only effective connectivity method to aggregate across participants, thus maximizing statistical power (i.e., the effective sample size is the number of timepoints × participants).…”

Neuropsychological implication in possible antibody-negative limbic encephalitis: a clinical case report

“…22 Functional MRI has shown that the amygdala responds differentially to fearful versus happy facial expressions, depending on attentional processes. 23 Thus, the impaired fear recognition resulting from the amygdala damage seems to be due to its failure in directing the visual system to search, fixate, pay attention and use such information to identify emotions. 24…”

“…22 Functional MRI has shown that the amygdala responds differentially to fearful versus happy facial expressions, depending on attentional processes. 23 Thus, the impaired fear recognition resulting from the amygdala damage seems to be due to its failure in directing the visual system to search, fixate, pay attention and use such information to identify emotions. 24 The findings of the present case were in line with other research that has shown that bilateral damage to the medial temporal lobe, including the amygdala and not just hippocampal damage, is associated with alterations in autobiographical recollections.…”

A distinct intra-individual suppression subnetwork in the brain’s default mode network across cognitive tasks

“…(2000) , and assessed implicit emotional processing to negatively valanced facial stimuli. The task has been examined in previous work by our group ( Jamieson et al. 2021 ).…”