@article{ref1,
title="A window into the tired brain: neurophysiological dynamics of visuospatial working memory under fatigue",
journal="Human factors",
year="2022",
author="Karthikeyan, Rohith and Carrizales, Joshua and Johnson, Connor and Mehta, Ranjana K.",
volume="ePub",
number="ePub",
pages="ePub-ePub",
abstract="OBJECTIVE: We examine the spatiotemporal dynamics of neural activity and its correlates in heart rate and its variability (HR/HRV) during a fatiguing visuospatial working memory task. <br><br>BACKGROUND: The neural and physiological drivers of fatigue are complex, coupled, and poorly understood. Investigations that combine the fidelity of neural indices and the field-readiness of physiological measures can facilitate measurements of fatigue states in operational settings. <br><br>METHOD: Sixteen healthy adults, balanced by sex, completed a 60-minute fatiguing visuospatial working memory task. Changes in task performance, subjective measures of effort and fatigue, cerebral hemodynamics, and HR/HRV were analyzed. Peak brain activation, functional and effective connections within relevant brain networks were contrasted against spectral and temporal features of HR/HRV. <br><br>RESULTS: Task performance elicited increased neural activation in regions responsible for maintaining working memory capacity. With the onset of time-on-task effects, resource utilization was seen to increase beyond task-relevant networks. Over time, functional connections in the prefrontal cortex were seen to weaken, with changes in the causal relationships between key regions known to drive working memory. HR/HRV indices were seen to closely follow activity in the prefrontal cortex. <br><br>CONCLUSION: This investigation provided a window into the neurophysiological underpinnings of working memory under the time-on-task effect. HR/HRV was largely shown to mirror changes in cortical networks responsible for working memory, therefore supporting the possibility of unobtrusive state recognition under ecologically valid conditions. APPLICATIONS: Findings here can inform the development of a fieldable index for cognitive fatigue.<p /> <p>Language: en</p>",
language="en",
issn="0018-7208",
doi="10.1177/00187208221094900",
url="http://dx.doi.org/10.1177/00187208221094900"
}