Assessment of Mental Fatigue During Examination Period with P300 Oddball Paradigm

Mental fatigue refers to the effects that people experience during and following prolonged periods of cognitive activity that requires work efficiency. Undergraduate students are faced with increased cognitive demands during the examination period that can lead to a higher level of perceived mental fatigue. The P300 component of the event-related potentials is considered an indicator of cognitive information processing, attention allocation and immediate memory. Variation in the P300 component has been linked to a fluctuation in natural and environmentally induced states. In order to evaluate the effects of sleepiness and the mental fatigue we used visual discrimination task to evoke the P300 potential. Reaction time (RT) to deviant stimuli and number of errors were also recorded. Several features of P300 evoked related potential, such as maximum and minimum amplitude, and latency were extracted to evaluate subject's performance in two sessions: during rested period and tired period. Subjects were placed into two sessions based on the battery of tests aimed to assess their arousal state. Rested state was recorded when subjects did not have any increased mental assignments. Tired state was recorded during their increased mental work overload during exam period. Results show a significantly smaller mean amplitude (p < 0.05) and slower RTs in a tired state.