Amidst the growing integration of AI into educational practices, concerns arise regarding how unregulated interaction with AI outside the structured classroom environment may influence university students’ cognitive functions. This research examines the differential effects of ChatGPT usage intensity on university students’ cognitive flexibility. The researchers hypothesize a negative correlation between ChatGPT usage and cognitive flexibility, measurable by increased response times and decreased accuracy between the two tasks of the Arrow Switch Test. We employed this test to contrast the performance of frequent (participants who used ChatGPT ≥ 50% of the time on academic assignments) and infrequent (participants who used ChatGPT ≤ 35% of the time on academic assignments) groups. For the purpose of this study, infrequent users were used as a control group. Both groups displayed a statistically significant decrease in task accuracy—highlighting the Arrow Switch Task’s efficacy in assessing cognitive flexibility—and response time between the first and second task. Notably, infrequent users of ChatGPT demonstrated a larger decline in accuracy and response time following changed task conditions compared to frequent users. This finding calls for further investigation into the longitudinal effects of AI tools on learning processes, necessitating a larger sample size and a more granular analysis of usage patterns to understand the subtleties of AI’s impact on cognitive flexibility.