Masters Applied Projects

Project 3

Sleep Deprivation’s Effect on the Startle Response

Student: Alexander Crawley

Mentors: Dr. Claire Honeycutt – SBHSE
Dr. Christopher Buneo – SBHSE
Dr. Megan Petrov – Edson College of Nursing and Health Innovation

YouTube Link: View the video link below before joining the zoom meeting

Zoom link: https://asu.zoom.us/j/4058046717?pwd=TWRUc0tBVjJtR0NJMTRaT1ZhcDFHdz09

Time: 10am – 2pm

Abstract

Sleep deprivation has become a feature in almost every American’s life. Early work or school start time creates a lasting sleep deficit as a person ages. The lack of sleep and progression of aging are strongly linked to learning deficits in both cognitive and motor skills. Older adults struggle to learn and retain new skills, leading to difficulties in physical therapy to relearn motor tasks after a traumatic effect or illness. This effect is exacerbated by poor sleep. Current research demonstrates motor learning is mediated in part by the reticulospinal system. Here, we seek to determine if sleep deprivation modulates the startle reflex, a well-established index of reticulospinal activation. The objective of this study is to determine if sleep deprivation is correlated to a delayed reticulospinal system measured by startle reflex modulating of sternocleidomastoid (SCM) muscle activity. We hypothesize that sleep deprivation will correspond to slower SCM onset latencies indicating reticulospinal delays. We collected data electromyography (EMG) data of the left and right SCM from 41 subjects during a passive reading task receiving 15 startles within 10 minutes and administered functional performance assessments over two sessions in a crossover model. Subject participated in two experimental sessions: one control or fully rested and one sleep deprived session. The functional performance assessments measure cognitive skills, motor skills, balance, and reaction time tests. Contrary to our hypothesis, there were no delays in muscle onset latencies. The average onset latency of the right SCM increased from 74.32 ± 22.15 ms when rested to 76.71 ± 24.44 ms when sleep deprived (p= 0.330) while the left SCM decreased from 76.04 ± 21.38 when rested to 73.49 ± 18.17 ms when sleep deprived (p= 0.156). However, 7 of the 8 functional performance assessments were significantly different between to the rested and sleep deprived conditions (p<0.05). This study suggests that although subjects were sleep deprived (confirmed by significantly worse functional performance assessments), the startle reflex as illustrated by sternocleidomastoid activity may not be an effective indicator of sleep deprivation. If the SCM is a reliable measure of startle, onsets would consistently modulate between experimental sessions demonstrating sleep deprivation is not correlated with delays in the reticulospinal system. This indicates physical therapies utilizing the startle response to learn motor tasks will be beneficial for older populations known large sleep deficits.