Effect of Biological Rhythm on Cognitive Performance

Biological rhythm has contributed in evolution process of humankind and has created certain distinct capabilities and preferences in shaping his phycho-psychological reactions. On the basis of behavioural activities, reactions, preferences and performances during the day-night cycle, individuals are classified in chronotype as morning type (M type) and evening type (E type). Such a differentiation has been hypothesised to contributing to individual differences at the cognitive, affective and conative levels. The present study was an attempt to further study such differentiation in terms of neuro cognitive performance by using the most advanced psycho-physiological measures. The participants of both chronotypes, morning and evening were classified and later subjected to cognitive testing by using the Cambridge Neuropsychological Test Automated Battery in the morning and the evening session under repeated measure design. The study revealed that performance on neuro cognitive functions; Planning and working memory, Decision-making and response control, and Motor skills get effected differently by their biological rhythm cycle and thus under performance in these functions can be attributed to maladaptation of biological rhythm termed as biological dysrhythmia. The study also highlights the role of this behavioural maladaptation in moderating operational efficiency of soldier in combat situation.