Effect of transcranial electrical brain stimulation on working memory performance in healthy participants.

INTERVENTION: Intervention1: Real Individualized theta high definition transcranial alternating current stimulation (Real theta HD tACS): Single session of Real theta HD tACS (2mA, 30 mins) on left intraparietal sulcus. Total duration is 30 mins. Control Intervention1: Sham theta high definition transcranial alternating current stimulation(Sham theta HD tACS): Single session of sham theta HD tACS, subject will receive 2mA theta HD tACS for 15 sec at both the start and the end of 30 mins session on left intraparietal sulcus. During the 30 mins session there is no tACS stimulation given between the initial 15 sec of the session and last 15 second of the session.Total duration is 30 mins. CONDITION: PRIMARY OUTCOME: Post Stimulation working memory performance will be assesed using: ; ; Corsi block tapping task ; Digit span tasks ; N‐back task ; Visuospatial working memory task ; ; Timepoint: Outcome will be assessed at baseline/pre‐intervention and Day 0 i.e. immediately after intervention. ; ; Each participant will undergo two experimental sessions, one involving real HD‐tACS and the other sham stimulation in a counterbalanced, single‐blind crossover design. 2 weeks interval will separate 2 sessions. SECONDARY OUTCOME: functional EEG connectivity of frontoparietal network. ; Timepoint: Baseline resting state EEG (10 mins) every session. INCLUSION CRITERIA: 1. Healthy Participant. 2. Sex: Male participants. 3. Age: between 19‐35 years. 4. Right‐handed. 5. Able to perform Computer Tasks. 6. Written informed consent. 7. Corrected Visual Acuity 6/6.