Modulating prefrontal cortex activity to alleviate stress-induced working memory deficits: A transcranial direct...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neuromodulation

Background:

• Stress significantly impairs cognitive functions, particularly working memory (WM).
• Non-invasive brain stimulation techniques like transcranial direct current stimulation (tDCS) show potential for mitigating stress-induced cognitive deficits.
• Identifying specific brain regions targeted by tDCS is crucial for optimizing interventions.

Purpose of the Study:

• To investigate the impact of stress on WM performance.
• To examine the efficacy of tDCS over the left dorsolateral prefrontal cortex (dlPFC) and ventromedial prefrontal cortex (vmPFC) in mitigating stress-induced WM deficits.
• To explore the neurophysiological mechanisms underlying the effects of tDCS on stress and WM.

Main Methods:

• A mixed, randomized, single-blind, sham-controlled design was employed.
• Stress was induced using aversive video clips, and WM performance was assessed using a verbal n-back task.
• Physiological (cortisol, heart rate), behavioral, and electroencephalographic (EEG) data were collected and analyzed.

Main Results:

• Stress impaired WM performance (3-back load) and elevated physiological stress markers in the sham condition.
• tDCS over the vmPFC improved WM task performance and blunted cortisol release compared to sham.
• EEG analysis indicated vmPFC stimulation reduced P200 amplitude and increased alpha desynchronization, suggesting reduced distraction and enhanced focus.

Conclusions:

• The vmPFC is a potential target for interventions aimed at mitigating stress effects on WM.
• tDCS over the vmPFC demonstrates promise in reducing stress-related cognitive impairments.
• This research contributes to developing targeted interventions for stress-related cognitive deficits.