Date of Award

Spring 5-8-2021

Document Type

Honors Thesis


Basic Biomedical Science

First Advisor

Dr. Lee Baugh

Second Advisor

Dr. Arun Singh

Third Advisor

Dr. Taylor Bosch


circadian typology, desynchrony, chronotype, attention, EEG

Subject Categories

Behavioral Neurobiology | Biology


The human circadian system plays an important role in biological and psychological processes in both health and disease. Circadian typology refers to individual differences in circadian rhythm and is categorized into three general chronotypes: morning, evening, and neither. Research suggests that an individual’s diurnal preference may be associated with differences in cognitive abilities, personality traits, and incidence of psychiatric disorders. In the present study, we utilized a Sustained Attention to Response Task (SART) and an electroencephalogram (EEG) in a desynchrony protocol. Morning-type and evening-type participants completed a SART task on two separate occasions during which brain activity was recorded. This allowed us to examine the difference in the underlying neural networks corresponding to alerting and sustained arousal when participants are in-phase versus out-of-phase of their diurnal preference. When examining both reaction times and response accuracy, performance and EEG differences were observed between participants’ optimal testing time, where we found decreased performance in out-of-phase testing sessions. This suggests that differences in task performance may be instantiated through transient changes in brain network function. These preliminary results may offer further insight into how task performance can change throughout the day and the neural networks associated with those performance changes.



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