title: Resting spontaneous activity in the default mode network predicts performance decline during prolonged attention workload.
abstract: After continuous and prolonged cognitive workload, people typically show reduced behavioral performance and increased feelings of fatigue, which are known as "time-on-task (TOT) effects". Although TOT effects are pervasive in modern life, their underlying neural mechanisms remain elusive. In this study, we induced TOT effects by administering a 20-min continuous psychomotor vigilance test (PVT) to a group of 16 healthy adults and used resting-state blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to examine spontaneous brain activity changes associated with fatigue and performance. Behaviorally, subjects displayed robust TOT effects, as reflected by increasingly slower reaction times as the test progressed and higher self-reported mental fatigue ratings after the 20-min PVT. Compared to pre-test measurements, subjects exhibited reduced amplitudes of low-frequency fluctuation (ALFF) in the default mode network (DMN) and increased ALFF in the thalamus after the test. Subjects also exhibited reduced anti-correlations between the posterior cingulate cortex (PCC) and right middle prefrontal cortex after the test. Moreover, pre-test resting ALFF in the PCC and medial prefrontal cortex (MePFC) predicted subjects' subsequent performance decline; individuals with higher ALFF in these regions exhibited more stable reaction times throughout the 20-min PVT. These results support the important role of both task-positive and task-negative networks in mediating TOT effects and suggest that spontaneous activity measured by resting-state BOLD fMRI may be a marker of mental fatigue.
authors.affiliation: Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA.|National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China.
authors.forename: Danyang
authors.initials: D
authors.lastname: Gui
authors.affiliation: Department of Applied Psychology, Guangdong University of Finance and Economics, Guangzhou, China.|Department of Psychology, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Sihua
authors.initials: S
authors.lastname: Xu
authors.affiliation: Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA.|Department of Psychology, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Senhua
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA.|Department of Psychology, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Fang
authors.affiliation: Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA.|Center for Sleep and Circadian Neurobiology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Spaeth
authors.affiliation: School of Psychology, Southwest University, Chongqing, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Xin
authors.affiliation: School of Psychology, Southwest University, Chongqing, China.
authors.forename: Tingyong
authors.initials: T
authors.lastname: Feng
authors.affiliation: Center for Functional Neuroimaging, Department of Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA.|Laboratory of Applied Brain and Cognitive Sciences, College of International Business, Shanghai International Studies University, Shanghai, China.|Department of Psychology, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Hengyi
authors.initials: H
authors.lastname: Rao
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D015415:Biomarkers; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D005222:Mental Fatigue / Q000503:physiopathology*; D009415:Nerve Net / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D013788:Thalamus / Q000502:physiology; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Amplitudes of low-frequency fluctuation (ALFF); Default mode network (DMN); Fatigue; Functional connectivity; Time-on-task (TOT) effects