Dual-target tACS improves working memory performance and modulates neural connectivity in healthy individuals

A single-blind, sham-controlled randomized trial evaluated the effects of high-definition transcranial alternating current stimulation (tACS) on working memory in 45 healthy participants. The study compared dual-target tACS, single-target tACS, and sham stimulation, with outcomes including working memory performance on n-back tasks, task-related cortical activation measured via functional near-infrared spectroscopy (fNIRS), and functional connectivity within brain networks.

Dual-target tACS improved working memory performance, particularly under higher cognitive load conditions, and yielded a greater proportion of responders compared to sham stimulation. Single-target stimulation showed relatively limited effects. The dual-target approach modulated task-related cortical activation in prefrontal and temporal regions and enhanced both intra- and inter-hemispheric functional connectivity. Improvements in task accuracy were associated with strengthened functional connectivity within the frontoparietal and default mode networks.

The abstract does not report specific effect sizes, p-values, confidence intervals, or absolute numbers for these outcomes. No safety, tolerability, or adverse event data are reported. The study population consisted of healthy individuals, limiting direct applicability to clinical populations with working memory impairments.

While dual-target tACS may represent a promising strategy for cognitive enhancement through network-level modulation, these findings are preliminary. The lack of reported quantitative effect measures and safety information precludes strong clinical conclusions. Further research with larger samples, clinical populations, and comprehensive safety reporting is needed.