Background: Mental fatigue is a common consequence of sustained cognitive activity among undergraduate students and may adversely affect attention and information processing. Reaction time represents an objective and quantifiable measure of cognitive performance and may serve as an indicator of mental fatigue. The present study aimed to evaluate visual and auditory reaction times in relation to perceived mental fatigue among undergraduate students. Material and methods: A cross-sectional observational study was conducted among 146 undergraduate students aged 18–25 years. Mental fatigue was assessed following a minimum of three hours of continuous academic activity using a visual analog scale (VAS). Based on VAS scores, participants were categorized into low, moderate, and high mental fatigue groups. Visual and auditory reaction times were measured using a computerized reaction time assessment tool. Mean reaction times were compared across fatigue levels, and correlations between fatigue scores and reaction time were analyzed using appropriate statistical tests. Results: Of the 146 participants, 30.1% reported low mental fatigue, 41.8% moderate fatigue, and 28.1% high fatigue. Visual and auditory reaction times increased progressively with higher levels of mental fatigue. Mean visual reaction time increased from 231.6 ± 21.4 ms in the low fatigue group to 278.7 ± 27.9 ms in the high fatigue group, while auditory reaction time increased from 198.9 ± 18.7 ms to 242.1 ± 23.6 ms, respectively (p < 0.01). Perceived mental fatigue scores showed a strong positive correlation with visual reaction time (r = 0.62) and auditory reaction time (r = 0.58) (p < 0.01). No significant differences in reaction time were observed between male and female students. Conclusion: Reaction time demonstrates a significant association with mental fatigue in undergraduate students and may serve as a reliable, objective marker for assessing fatigue-related cognitive impairment in academic environments.

Mental fatigue; Reaction time; Undergraduate students; Cognitive performance; Visual and auditory stimuli