The Effect of Chronotype on Task Execution -Is it really inefficient that Evening types perform tasks in the morning?-

Abstract

The aim of this study was to investigate the effect of chronotype on task execution from the point of view of psychology, physiology and brain science. 224 university students were measured chronotype by Japanese version of the Morningness-Eveningness Questionnaire and fifteen Morning type and fifteen Evening type were selected. We conducted a series of psychological tasks in morning and evening respectively, and measured task execution, autonomic nerve activity during tasks, and the transition of oxygen saturation of prefrontal cortex with f-NIRS. As a result, we observed a significant difference in behavioral indicators in the early part of the task (optimal condition > non-optimal condition) and compensatory brain activities in non-optimal condition. The change in autonomic nerve activity was close to significance. These results suggest that chronotype affects the fundamental cognitive ability necessary for task execution.