Date of Award


Degree Type




First Advisor

Wallace, Benjamin

Subject Headings

Time perception, Cognition, Memory, Executive function, aging, time of day


The most recent time-of-day (TOD) body of research has explored how TOD effects can influence certain cognitive domains such as semantic memory, episodic memory, processing speed, and executive functioning (Allen et al., 2008). Research by Horne and Ostberg (1976) has shown how differences in age can be associated with a preference for a certain TOD (i.e., morning or afternoon). Seventy-five percent of adults 65 years or older tend to prefer the morning, whereas fewer than 10 of younger adults tend to prefer the afternoon (Horne & Ostberg, 1976 West et al., 2002). Research by Allen and colleagues (2008) has shown how performance on certain tasks related to assessing different cognitive domains can be influenced by TOD effects (Allen et al., 2008 Intons-Peterson, Rocci, West, McLellan, & Hackney, 1998 May & Hasher, 1998 May, Hasher, & Stoltzfus, 1993). The adult western society has tended to focus on morning performance however, the opposite effect is seen for younger adults. Morning performance has been found to be slightly impaired for younger adults when compared to older adult performance in the morning, and younger adults have shown the greatest advantage on tasks performed in the afternoon, when compared to older adults. To date, research has not examined the effects from TOD using a comprehensive and standardized measure of executive functioning (i.e., The Delis-Kaplin Executive Function System or D-FEFS) to compare difference in younger and older adult performance. The current study was intended to extend on the Allen et al. research and examine younger and older adult performance on executive functioning when they are tested at their preferred TOD or less preferred TOD

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Psychology Commons