Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Applied Cognitive Science and Human Factors (MS)

Administrative Home Department

Department of Cognitive and Learning Sciences

Advisor 1

Samantha Smith

Committee Member 1

Kevin Trewartha

Committee Member 2

Shane Mueller

Committee Member 3

Carolyn Duncan


Vigilance, otherwise known as a state of alert watchfulness, is a phenomenon that occurs when someone is sustaining their attention on a particular task or environment. Largely, tasks that require a state of vigilance induce negative mood outcomes, result in loss of performance over time, and cause increased disengagement from the task. These tasks involve detecting critical signals which are buried among more frequently occurring neutral signals. While little can be done to change the base nature of the vigilance task, altering the physical environment of the operator may improve working conditions to a point where there are fewer losses of engagement and declines in arousal. Previous research has found that exposure to bright short-wavelength light can improve sleepiness, alertness, and mood. In other research, music has been found to positively impact cognitive function and response times. The first study examined the efficacy of using a bright light therapy lamp during vigilance performance to minimize the decline in alertness and arousal. There were 50 participants placed into two conditions: A bright light therapy lamp and dim light. Results indicated that the therapy light did not prevent a decline in detection of critical signals over time, nor significantly impact workload, sleepiness, or subjective stress state compared to a dim light condition. However, mood questionnaire results suggest that lighting may impact separate constructs of arousal and tiredness, warranting further research. The second study determined differently tempoed music, namely fast and slow tempos, did not significantly impact operator engagement and response time. It also recruited 50 participants but had 3 conditions: fast tempo, slow tempo, and silence. Results indicated that varying music tempo did not influence the typical decline in detection of critical signals, but the fast tempo condition had a modestly positive impact on worry and engagement from pre- to post-task.