Facial expression primes and implicit regulation of negative emotion

Major depressive disorder associated alterations in the effective connectivity of the face processing network: a systematic review

Major depressive disorder (MDD) is marked by altered processing of emotional stimuli, including facial expressions. Recent neuroimaging research has attempted to investigate how these stimuli alter the directional interactions between brain regions in those with MDD; however, methodological heterogeneity has made identifying consistent effects difficult. To address this, we systematically examined studies investigating MDD-associated differences present in effective connectivity during the processing of emotional facial expressions. We searched five databases: PsycINFO, EMBASE, PubMed, Scopus, and Web of Science, using a preregistered protocol (registration number: CRD42021271586). Of the 510 unique studies screened, 17 met our inclusion criteria. These studies identified that compared with healthy controls, participants with MDD demonstrated (1) reduced connectivity from the dorsolateral prefrontal cortex to the amygdala during the processing of negatively valenced expressions, and (2) increased inhibitory connectivity from the ventromedial prefrontal cortex to amygdala during the processing of happy facial expressions. Most studies investigating the amygdala and anterior cingulate cortex noted differences in their connectivity; however, the precise nature of these differences was inconsistent between studies. As such, commonalities observed across neuroimaging modalities warrant careful investigation to determine the specificity of these effects to particular subregions and emotional expressions. Future research examining longitudinal connectivity changes associated with treatment response may provide important insights into mechanisms underpinning therapeutic interventions, thus enabling more targeted treatment strategies.

Effects of high-definition transcranial direct current stimulation on implicit emotion regulation of social pain in healthy individuals

BACKGROUND

Implicit emotion regulation (ER), a form of ER, is essential for protecting mental health in the process of social interaction. Both the ventrolateral prefrontal cortex (VLPFC) and the dorsolateral prefrontal cortex (DLPFC) have been shown to be involved in ER processes, including explicit ER of social pain, but whether they play a role in implicit ER is unclear.

METHODS

We investigated whether anodal high-definition transcranial direct current stimulation (HD-tDCS) of the right VLPFC (rVLPFC) or the right DLPFC (rDLPFC) influences implicit ER. In total, 63 healthy participants completed an emotion priming task, which measures the implicit ER of social pain, before and after receiving active or sham HD-tDCS (2 mA for 20 min, 10 consecutive days). Event-related potentials (ERPs) were recorded during task performance.

RESULTS

Combined with the results of the behavioral and electrophysiological indices indicated that stimulation of both the rVLPFC and the rDLPFC by anodic HD-tDCS could significantly reduce the affective responses caused by social exclusion. The further results also suggested that rDLPFC activation may contribute to promoting the involvement of early cognitive resources in the implicit ER process of social pain, thus helping to reduce the subjective negative experience of individuals.

LIMITATIONS

There were no dynamic interactive emotional stimuli to induce social pain, and only static images of social exclusion were used.

CONCLUSION

Our study provides cognitive and neurological evidence that expands our knowledge of the role of the rDLPFC and the rVLPFC in social ER. It can also serve as a reference for targeted intervention of implicit ER in social pain.

Neural correlates of Type A personality: Type A personality mediates the association of resting-state brain activity and connectivity with eating disorder symptoms

BACKGROUND

Type A personality (TAP) was characterized by impatience, competitiveness, aggressiveness, and hostility. Higher TAP was proved to be associated with more eating disorder symptoms (EDS). While little is known about the underlying neural substrates of TAP and how TAP is linked to EDS at the neural level.

METHODS

To investigate the neural basis of TAP, we adopted fractional amplitude of low-frequency fluctuations (fALFF) and resting-state functional connectivity (RSFC) via resting-state functional magnetic resonance imaging (rs-fMRI) (N = 1620). Mediation models were examined to explore the relationship between TAP, EDS, and brain activity.

RESULTS

TAP was associated with decreased fALFF in the left middle frontal gyrus (MFG) and increased fALFF in the left precentral gyrus (PreCG). Furthermore, TAP was positively correlated to RSFC between the left MFG and left inferior temporal gyrus (ITG) and between the left PreCG and right middle temporal gyrus (MTG). Mediation analysis showed TAP fully mediated the association of the left MFG activity, MFG-ITG connectivity, and PreCG-MTG connectivity with EDS.

LIMITATIONS

The cross-sectional design of this study precludes us from specifying the causal relationship in the associations we observed.

CONCLUSIONS

Our results suggested spontaneous activity in the left MFG and PreCG is associated with TAP, and even in general sample, people with higher TAP showed more EDS. The present study is the first to investigate the neurobiological underpinnings of TAP in a large sample and further offered new insights into the relation between TAP and EDS from a neural basis perspective.

Different Neural Correlates of Automatic Emotion Regulation at Implicit and Explicit Perceptual Level: A Functional Magnetic Resonance Imaging Study

Automatic emotion regulation (AER) is an important type of emotion regulation in our daily life. Most of the previous studies concerning AER are done in the conscious level. Little is known about the AER under the subliminal level. The present study was to investigate the AER at the different perceptual levels (i.e., explicitly and implicitly) simultaneously, and the associated neural differences using functional magnetic resonance imaging. Priming paradigm was adopted in which the inhibition or neutral words were used as primes and the negative picutres were used as targets. In the experiment, the duration time of priming words was manipulated at 33 or 50 ms in the implicit level and 3000 ms in the explicit level. The participants were required to make emotional valence rating of the negative pictures while undergoing functional magnetic resonance imaging scanning. The results showed that the participants experienced less negative emotion in inhibition words priming condition contrary to neutral words priming condition. Significant differences were also found in the left ventrolateral prefrontal cortex and left dorsolateral prefrontal cortex at the implicit and explicit AER. The findings of this study demonstrate that inhibition words can automatically and effectively reduce an individual's negative emotion experience, and left ventrolateral prefrontal cortex and left dorsolateral prefrontal cortex have been both implicated in self-control during AER.

The Role of Emotion Regulation in Reducing Emotional Distortions of Duration Perception

Emotional events, especially negative ones, are consistently reported to last longer than neutral events. Previous studies suggested that this distortion of duration perception is linked to arousal and attention bias in response to emotional events. Reappraisal and suppression, arguably the most effective strategies for emotion regulation, have been demonstrated to decrease such arousal and attention bias. The present study investigated whether reappraisal and suppression can reduce emotional distortions of duration perception. Seventy-eight Chinese undergraduates were recruited as paid participants and randomly assigned to nonregulation, reappraisal, and suppression groups. Before they performed a temporal bisection task involving presentation of emotional pictures for different durations, the groups were each given one of three different sets of instructions requiring them to passively perceive, reappraise, or suppress the emotions of the pictures. The results indicated that the distortion of duration perception occurred only in the nonregulation group, suggesting that it can be effectively reduced by reappraisal and suppression.

Temporal course of implicit emotion regulation during a Priming-Identify task: an ERP study

Implicit emotion regulation defined as goal-driven processes modulates emotion experiences and responses automatically without awareness. However, the temporal course of implicit emotion regulation is not clear. To address these issues, we adopted a new Priming-identify task (PI task) to manipulate implicit emotion regulation directly and observed the changes of early (N170), middle (early posterior negativity, EPN), and late event-related potentials (ERPs) components (late positivity potentials, LPP) under the different implicit emotion regulation conditions. The behavioral results indicated that the PI task manipulated subjective emotion experience effectively by priming emotion regulation goals. The ERP results found that implicit emotion regulation induced more negative N170 without altering the EPN and the LPP amplitudes, indicating that implicit emotion regulation occured automatically in the early perceptual stage not in the late selective attention stage of emotion processing. The correlation analysis also found the enlarged N170 was associated with decreased negative emotion subjective rating, suggesting that the N170 was probably an effective index of implicit emotion regulation. These observations imply that implicit emotion regulation probabbly occurs in the early stage of emotion processing automatically without consciousness.