Frontal Application of 7 and 40 Hz tACS Enhances Working Memory Function

working memory transcranial electrical stimulation alternating current stimulation gamma frequency theta frequencyEffectively applied transcranial electrical stimulation yields potential for enhancing the function of various cognitive domains, making it a promising point of investigation in the field of neuroscience.The current study explored the comparative effectiveness of theta (7 Hz) and gamma (40 Hz) transcranial alternating current stimulation (tACS) in enhancing the features of working memory (WM), specifically the central executive and visuospatial components, as assessed by a 2-back task.Frontofrontal tACS was employed to investigate the impact of these two frequency bands on a sample of 112 healthy participants in the age range of 18-20 years.Our findings provide support for WM improvement as both frontal theta-tACS and gamma-tACS exhibited superior outcomes when compared to sham stimulation.Furthermore, stronger improvements in WM were observed in the context of 40 Hz stimulation as contrasted with 7 Hz stimulation during both online and post-stimulation assessments.Overall, we observed that the initial online enhancements in cognitive performance are associated with entrainment, whereas long-term offline effects are attributed to plasticity.This study contributes to the evolving landscape of tACS research and emphasizes the need for further investigations into the intricate interactions between tACS parameters, task load, and individual characteristics to enhance the therapeutic potential of neuromodulation techniques for WM enhancement.