Photo By Megan Mudersbach | Naval Medical Research Unit Dayton’s Naval Aerospace Medical Research Laboratory...... read more read more
By: Drs. Daniel McHail, Kyle Pettijohn, Kara Blacker, and Lt. Sarah Sherwood
Operational demands often require the warfighter to maintain attention for long periods of time, for example while standing watch or searching satellite images. However, performance on attention-driven tasks starts to degrade after a period of sustained effort. This effect is due to mental fatigue and can occur in as little as 20 minutes of time on task. To help maximize warfighter performance on tasks requiring sustained attention, it is critical to understand how the brain responds to mental fatigue.
A seedling effort at the Naval Medical Research Unit Dayton (NAMRU-Dayton) Naval Aerospace Medical Research Laboratory (NAMRL), sponsored by the Office of Naval Research, is currently underway to investigate the effects of mental fatigue on attentional control and associated neural activity. In this study, participants perform computerized tasks that assess their ability to monitor and quickly choose a correct response to a series of visual stimuli. In one variation of the task, participants respond frequently but then withhold their response to frequent stimuli. Together, these tasks tap into cognitive processes that require attention and control through inhibition. Prior to performing these tasks, participants either watch a short video or perform a different attention-demanding task. The prior attention-demanding task is expected to induce mental fatigue and influence subsequent performance.
While participants perform these tasks, researchers monitor changes in blood oxygenation in the participant’s prefrontal cortex (PFC), a region of the brain involved in attention. Generally, increased blood oxygenation in a brain region indicates greater activation of that region. The device that monitors blood oxygenation uses a technique called near-infrared spectroscopy (NIRS). It consists of light sensors embedded in a headband that can be quickly applied and comfortably worn over the forehead. The NIRS system, when compared to other methods of assessing brain activity, is relatively inexpensive and easy to use. These factors will make it easier to transition findings from this study to follow-on efforts in a variety of operational contexts.
Our preliminary findings suggest that mental fatigue did not negatively affect participants’ performance on the attention-driven tasks. However, PFC activation was greater with mental fatigue. This suggests that the brain responded to mental fatigue by ramping up PFC activity in these individuals to maintain performance. This difference in PFC activity was only apparent during the task variation that required both attention and control through inhibition. Once we complete data collection and analysis we will be able to confirm whether or not this trend persists.
Results from this initial study will help us clarify how mental fatigue impacts attentional control and how the brain responds to maintain performance. Looking forward, our follow-on studies will aim to identify individual differences in susceptibility to mental fatigue as well as the effects of mental fatigue on other cognitive abilities including multi-tasking. These results can be used to inform future efforts to develop fatigue countermeasures during tasks that require sustained attention.
A special thanks to team members supporting this study: Caitlin O’Guin, Cammi Borden, Ashley Murray, and Lee Wintermute.
| Date Taken: | 01.26.2021 |
| Date Posted: | 01.26.2021 15:25 |
| Story ID: | 387665 |
| Location: | WRIGHT-PATTERSON AIR FORCE BASE, OHIO, US |
| Web Views: | 258 |
| Downloads: | 0 |
This work, Navy Researches Impacts of Cognitive Fatigue on Attention and Neural Activity, by Megan Mudersbach, identified by DVIDS, must comply with the restrictions shown on https://www.dvidshub.net/about/copyright.
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