The Effect of Transcranial Direct Current Stimulation on Risky Decision-Making of Student Chess Players Based on their Introverted and Extroverted Personality Traits

The aim of this research was to investigate the effects of transcranial direct current stimulation (tDCS) on risky decision-making in student chess players, taking into account their personality traits. In this study, 28 high school students who were active in chess and participated in provincial and national chess leagues were selected. Based on the NEO Five-Factor Inventory of personality traits, they were divided into two groups: 14 extroverted students (17 ± 0.88) and 14 introverted students (16.5 ± 1.02). Each participant attended three separate sessions in the laboratory, with a minimum 72-hour rest period between sessions. In each session, participants performed the Iowa Gambling Task and the Lichess computer game before any stimulation. They were then subjected to one of three conditions: right anodal/left cathodal, right cathodal/left anodal, or sham stimulation, for 20 minutes at 2 mA intensity over the dorsolateral prefrontal cortex. After the stimulation, participants repeated the Iowa Gambling Task and the Lichess computer game. Data analysis using two-way mixed ANOVA revealed a significant difference in the Iowa Gambling Task between right anodal/left cathodal and right cathodal/left anodal stimulation based on personality traits (p = 0.001). The findings of this study indicated that transcranial direct current stimulation had a differential effect on decision-making in chess players based on their personality traits. Specifically, the study’s results showed that extroverted players exhibited more risk-taking behaviour, while introverted players acted more cautiously.