Transcranial direct current stimulation over prefrontal cortex did not improve the decision-making skill of athletes exposed to prolonged social media use: a crossover and randomised investigation

In the sport literature body, mental fatigue has been shown to impair decision-making skills, and tDCS over PFC is an alternative countermeasure for this phenomenon that has aroused interest. Thus, this study aimed to verify the effect of transcranial direct current stimulation (tDCS) over prefrontal cortex (PFC) on the attack decision-making skill of beach volleyball players exposed to prolonged social media use. An experimental crossover and randomised design was used in this study. Twelve male beach volleyball players underwent tDCS [anodal Fz (10/20 system), 2 mA] and sham conditions. In both conditions, the players used social media for 30 min on their smartphones (mental fatigue protocol) and tDCS was applied for 20 min immediately prior attack decision-making task. Mental fatigue was measured using a visual analogue scale, executive functions (inhibitory control) were verified using the Strop task, and decision-making skill was assessed using the Game Performance Assessment Instrument (GPAI) for attack and counterattack actions. There was an increase in subjective mental fatigue after social media use (pre: 1.233 +/- 0.334 vs. post: 1.455 +/- 0.302, p = .022, d = 0.697, moderate effect). However, Stroop and decision-making performance were similar across conditions (p > .05). In conclusion, tDCS over the PFC did not reduce mental fatigue caused by social media. Moreover, this montage did not improve the inhibitory control or attacking decision-making skills of beach volleyball players.