Exploring neural correlates of social dominance: Insights from behavioral, resting- state EEG, and ERP indices.

Numerous studies have explored the concept of social dominance and its implications for leadership within the behavioral and cognitive sciences in recent years. The current study aims to address the gap regarding the neural correlates of social dominance by investigating the associations between psychological measures of social dominance and neural features among a sample of leaders. Thirty healthy male volunteers engaged in a monetary gambling task while their resting-state and task-based electroencephalography data were recorded. The results revealed a positive association between social dominance and resting-state beta oscillations in central electrodes. Furthermore, a negative association was observed between social dominance and task-based reaction time as well as the amplitude of the feedback-related negativity component of the event-related potentials during the gain, but not the loss condition. These findings suggest that social dominance is associated with enhanced reward processing which has implications for social and interpersonal interactions.

Unilateral vs. bilateral DLPFC rTMS: comparative effects on depression, visual-spatial memory, inhibitory control and cognitive flexibility in major depressive disorder.

Background: Exciting left DLPFC activity with high frequency and inhibiting right DLPFC with low frequency repetitive transcranial magnetic stimulation (rTMS) has shown antidepressant effects in major depressive disorder (MDD) and executive functions. However, few studies have directly compared unilateral and bilateral protocols. Methods: Forty-seven individuals with treatment-resistant MDD underwent 10 sessions of rTMS over left DLPFC (20 Hz), bilateral DLPFC (left 20 Hz, right 1 Hz), or sham stimulation. Outcomes were depression (Beck Depression Inventory-II), visual-spatial memory (Corsi Block Test), response inhibition (Go/No-Go task), and cognitive flexibility (Wisconsin Card Sorting Test) assessed before and after treatment. Results: Both unilateral and bilateral rTMS significantly reduced depression levels versus sham controls based on BDI-II scores. While bilateral stimulation did not improve Corsi Test performance, unilateral protocol enhanced visual-spatial memory. On the Go/No-Go task, accuracy was higher in both active stimulation groups compared to sham, with no response time differences. Neither unilateral nor bilateral rTMS had significant effects on cognitive flexibility per the WCST. Conclusions: Despite comparable antidepressant effects, unilateral stimulation had some cognitive advantages over bilateral rTMS, potentially due to greater left dorsolateral prefrontal cortex excitation. Further research on parameter optimization is warranted.

The effectiveness of high-frequency left DLPFC-rTMS on depression, response inhibition, and cognitive flexibility in female subjects with major depressive disorder.

BACKGROUND: The purpose of the present study was to investigate the effect of high-frequency repetitive transcranial magnetic stimulation on depression severity, response inhibition, and cognitive flexibility in subjects with major depressive disorder. METHODS: Twenty-eight female subjects with major depressive disorder were randomly divided into experimental and control groups. High frequency (20 Hz) rTMS stimulation at 85% of the MT consisted of 25 trains of 5 s duration, a total of 2500 pulses/session or sham stimulation was applied over the left DLPFC for five consecutive days per week, for two weeks. Depression severity, response inhibition, and cognitive flexibility of subjects were assessed by Beck Depression Inventory, Go/NoGo, and Wisconsin sort cards (WCST) tests, respectively, pre- and post-TMS intervention. RESULTS: rTMS over the left DLPFC significantly decreased the depression severity at the Beck Depression Inventory, enhanced accuracy, and decreased reaction time at the Go/NoGo task. In the Wisconsin Card Sort Test, perseverative and non-perseverative errors and failure to maintain a set index significantly decreased following rTMS treatment. CONCLUSIONS: Findings indicate that 20-Hz rTMS treatment on the left DLPFC has a positive effect on depression severity, response inhibition, and cognitive flexibility in depressed subjects.