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Lee, T. M. C.

Publications and source records attributed to Lee, T. M. C..

3 recordsLinked to original sources

Sleep reactivation of positive self-evaluation reveals neural-evaluative alignment that varies with depressive symptoms

Positive self-evaluation underpins resilience and mental health, yet how to enhance positive self-evaluation and the underlying neurocognitive mechanisms remain poorly understood. Existing data mostly examined self-evaluative processing of the wakeful minds, with the role of sleep remain unexplored. Here, we demonstrated that reactivation of positive self-evaluation during sleep revealed fine-grained neural-evaluative alignment that varies with depressive symptoms. We found that targeted reactivation of positive personality traits during non-rapid eye movement (NREM) sleep enhanced positive self-evaluation, but this benefit diminished with elevated depressive symptoms. Moreover, cueing positive traits during NREM sleep elicited trait-specific, 11-16 Hz EEG sigma power-based neural representations that aligned with post-sleep positive self-evaluative representational structures, as revealed by representational similarity analyses. Notably, individuals with elevated depressive symptoms exhibited weaker neural-evaluative representational alignments, identifying a maladaptive self-evaluative processing that bridges across sleep and wakefulness states. These findings provide mechanistic insights on how fine-grained neural-evaluative alignment can substantiate positive self-evaluation, and why it was disrupted as depressive symptoms increased. HighlightsO_LIPositive-trait reactivation during NREM sleep enhances positive self-evaluation C_LIO_LIThis behavioral benefit decreases as depressive symptoms increase C_LIO_LISleep cueing evokes trait-specific sigma-band neural representations C_LIO_LINeural-evaluative alignment weakens as depressive symptoms increase C_LI

neuroscience↗

Trait Resilience Modulates the Association Between Cortisol and Aperiodic Neural Dynamics

Cortisol, our stress hormone, exerts widespread influence on neural activity. However, its influence on the aperiodic component of the electroencephalography power spectrum remains to be investigated. Given individual differences in the capacity to cope with stress and adversity, it also remains unclear whether trait resilience moderates this relationship. Hence, the present study examined whether individual differences in trait resilience moderates the association between resting cortisol and aperiodic activity. Participants (N=145) completed various self-report questionnaires (e.g., trait resilience). Electroencephalography was recorded over a 20-minute baseline period, followed by salivary cortisol collection. The results revealed a significant moderating effect of trait resilience in the occipital scalp region. Specifically, higher cortisol concentration was associated with flatter 1/f slopes amongst individuals with low trait resilience, whereas this association was reversed amongst those with high trait resilience. Overall, our findings highlight the role of individual differences in trait resilience in shaping hypothalamic-pituitary-adrenal axis-related neural dynamics.

neuroscience↗

The Effect of Transcranial Direct Current and Magnetic Stimulation on Fear Extinction and Return of Fear: A meta-analysis and Systematic Review

Anxiety and fear-related disorders are among the most prevalent mental illnesses. Non-invasive brain stimulation methods such as transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) have been employed to modulate anxiety and fear-related symptoms, but their therapeutic effects remain inconclusive. Pavlovian conditioning and extinction are experimental analogues of exposure therapy that investigate the neural mechanisms of fear extinction and return of fear. We conducted a meta-analysis and qualitative review on the effects of tDCS and TMS on fear extinction and return of fear in non-primate animals and humans. Results show that both anodal and cathodal tDCS over the prefrontal cortex inhibit short-term contextual and cued fear retrieval in animal models. In human studies, anodal tDCS over the medial/ventromedial prefrontal cortex enhances fear extinction, whereas TMS over the dorsolateral/ventromedial prefrontal cortex inhibits return of fear. Our findings suggest the optimal non-invasive brain stimulation protocols for threat extinction in humans.

neuroscience↗