MOTIVATION AS A CO-VARIATE FOR CHANGES IN COGNITIVE PERFORMANCE DURING SLEEP RESTRICTION

Open Access
Author:
Bailey, David Scott
Area of Honors:
Biobehavioral Health
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Orfeu Buxton, Thesis Supervisor
  • Lori Francis, Honors Advisor
Keywords:
  • Motivation
  • sleep restriction
  • neurocognitive performance
  • cognition
Abstract:
Today, people do not view sleep as a top priority. Oftentimes sleep takes a secondary role in people’s lives with negative health outcomes as a result. In experimental studies sleep restriction is imposed on study participants by limiting sleep opportunity over multiple days. As sleep duration is restricted, neurocognitive performance is decreased. However, laboratory models of sleep restriction require participants to undergo prolonged periods of time in the lab undergoing repeated, boring tests of neurocognitive performance. The participants experience can be mentally strenuous and lead to a decrease in motivation to continue participation with the same vigor as at the beginning of the study period. A decline in motivation has been implicated in decreasing neurocognitive performance similar to the decline in performance attributed to increased levels of sleepiness. Consequently, this thesis sought to examine the effects of motivation on neurocognitive performance during sleep restriction. The goals of the present study are to examine whether or not a decline in motivation causes a decrease in neurocognitive performance independent of the decline attributed to perceived sleepiness. We collected data within a larger 11-day inpatient study conducted at The Pennsylvania State University Clinical Research Center. Study participants were submitted to three conditions; baseline, restriction, and recovery. The baseline and recovery periods were defined as ten hours in bed for three and two nights respectively while restriction allowed for five hours in bed across five nights. Cognitive batteries were administered throughout each day followed by a survey that evaluated levels of motivation and sleepiness. The results of this study were that at the test level an increase in self-reported levels of sleepiness predicted a higher incidence of psychomotor vigilance task (PVT) lapses. The level of unmotivation was not significantly related to an increase in the number of PVT lapses.