title: Environmental heat stress enhances mental fatigue during sustained attention task performing: evidence from an ASL perfusion study.
abstract: This study was to investigate the potential enhancing effect of heat stress on mental fatigue progression during sustained attention task using arterial spin labeling (ASL) imaging. Twenty participants underwent two thermal exposures in an environmental chamber: normothermic (NT) condition (25°C, 1h) and hyperthermic (HT) condition (50°C, 1h). After thermal exposure, they performed a twenty-minute psychomotor vigilance test (PVT) in the scanner. Behavioral analysis revealed progressively increasing subjective fatigue ratings and reaction time as PVT progressed. Moreover, heat stress caused worse performance. Perfusion imaging analyses showed significant resting-state cerebral blood flow (CBF) alterations after heat exposure. Specifically, increased CBF mainly gathered in thalamic-brainstem area while decreased CBF predominantly located in fronto-parietal areas, anterior cingulate cortex, posterior cingulate cortex, and medial frontal cortex. More importantly, diverse CBF distributions and trend of changes between both conditions were observed as the fatigue level progressed during subsequent PVT task. Specifically, higher CBF and enhanced rising trend were presented in superior parietal lobe, precuneus, posterior cingulate cortex and anterior cingulate cortex, while lower CBF or inhibited rising trend was found in dorsolateral frontal cortex, medial frontal cortex, inferior parietal lobe and thalamic-brainstem areas. Furthermore, the decrease of post-heat resting-state CBF in fronto-parietal cortex was correlated with subsequent slower reaction time, suggesting prior disturbed resting-state CBF might be indicator of performance potential and fatigue level in following task. These findings may provide proof for such a view: heat stress has a potential fatigue-enhancing effect when individual is performing highly cognition-demanding attention task.
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Shaowen
authors.initials: S
authors.lastname: Qian
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Guoying
authors.initials: G
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Medical Imaging, Jinan Military General Hospital, Jinan, Shandong, People's Republic of China. Electronic address: cjr.sungang@vip.163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Sun
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D029721:Drosophila Proteins; D018882:Heat Stress Disorders / Q000503:physiopathology* / Q000523:psychology*; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000503:physiopathology*; D008991:Monitoring, Physiologic; D009483:Neuropsychological Tests; D055420:Perfusion Imaging; D010812:Physical Stimulation; D051096:Proto-Oncogene Proteins c-ret; D011597:Psychomotor Performance / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013113:Spin Labels; D055815:Young Adult
chemical_list: D029721:Drosophila Proteins; D013113:Spin Labels; D051096:Proto-Oncogene Proteins c-ret; C416649:Ret protein, Drosophila
keywords: Cerebral blood flow; Heat stress; Mental fatigue; Sustained attention