The effect of circadian rhythm on time perception in young adults

The aim of this thesis is to investigate the effect of circadian rhytm on time perception. In accordance with this aim; three complementary experiments were designed using behavioral and physiological methods. The effect of chronotype, time of day and target duration in Experimet 1; prospective and retrospective timing paradigms and time of day on time perception in Experiment 2A and 2B; and the relationship between time perception with body temperature and social jet lag in all experiments. In addition, the adoptation of Turkish culture, validity and reliability study of the Turkish version of Munich Chronotype Questionnaire (MCTQ-TR) was conducted within the context of the thesis. In Experiment 1 (N=33), production task in prospective paradigm at four different target duration (1 s, 5 s, 10 s, 15 s); in Experiment 2A (N=26), production, reproduction and verbal estimation tasks in prospective and retrospective paradigm at 10 s and in Experiment 2B (N=25), reproduction and verbal estimation tasks in both prospective and retrospective paradigm at 3 s were applied to different chronotypes of participants. Body temperature was measured with a non contact infrared thermometer in all experiments. Morningness-Eveningness Questionnaire (MEQ) and MCTQ-TR was applied to determine the chronotypes and social jet lag of the participants. As a result, the general findings of the three experiments within the context of the thesis study showed that time of day had an effect on time perception in different paradigms/tasks for short durations in seconds (1 s and 3 s) in young adults (intermediate and eveningness type). On the other hand, although a significant increase in body temperature from morning to evening and social jet lag for more than 1 hour were observed in all experiments, the assumption of a relationship between time perception, body temperature and social jet lag could not be supported. Keywords Time Perception, Prospective Timing Paradigm, Retrospetive Timing Paradigm, Circadian Rhythm, Body Temperature, Social Jet Lag, Munich Chronotype Questionnaire