Effect of Ramadan Fasting on Cognitive Functions Using P300 Event Related Potential and the Cancellation Test

Muslims abstain from eating, drinking, sexual activity from sunrise to sunset during the fasting month of Ramadan. This study is aimed at investigating the effect of Ramadan fasting on plasma glucose levels and cognitive functions such as attention, memory, decision making. The study was carried out with 15 healthy adult participants. P300 recordings and plasma glucose levels were taken from all participants in fasting and subsequently non-fasting period as control group. The cancellation test was also administered to assess sustained attention in both periods. P300 was recorded using auditory oddball paradigm which consisted of 120 standard and 40 target stimuli. Latencies and amplitudes of P300 to target and standard stimuli were analyzed. P300 wave is important component of auditory event-related potentials (ERPs) commonly used to examine cognitive function in decision making processes. There was a significant difference between mean plasma glucose levels in fasting and non-fasting period (93.73 ± 7.55 mg/dL and 112.80 ± 18.82 mg/dL, respectively) (P<0.05). P300 amplitudes to target stimuli during fasting were significantly (P<0.05) lower than those in the non-fasting period (11.22 ± 4.26 μV and 14.65 ± 3.59 μV, respectively). P300 amplitudes to standard stimuli during fasting were also significantly lower than those in the non-fasting period (11.84 ± 2.88 μV and 14.69 ± 2.54 μV, respectively) (P<0.05). P300 latencies to standard stimuli during fasting were significantly longer than those in the non-fasting period (348.21 ± 11.00 ms and 339.22 ± 15.26 ms, respectively) (P<0.05). Cancellation test completion time in fasting was significantly (P<0.05) longer than that in the non-fasting period (79.70 ± 10.83 sec and 67.41 ± 10.02 sec, respectively).These findings suggest that Ramadan fasting adversely affects cognitive functions such as perception, sustained attention and decision making.