Comparing the Effects of Three Cognitive Tasks on Indicators of Mental Fatigue

Abstract

This investigation assessed the impact of three cognitively demanding tasks on cognitive performance, subjective, and physiological indicators of mental fatigue. Following familiarization, participants completed four testing sessions, separated by 48 h. During each session, participants watched a 45-min emotionally neutral documentary (control) or completed one of the following computer tasks: Psychomotor Vigilance Task (PVT); AX-Continuous Performance Test (AX-CPT); or Stroop Task. Mental fatigue was assessed before and at regular periods for 60 min following the 45-min treatments. Cognitive performance was assessed using 3-min PVT, and task performance. Subjective assessments were conducted using the Brunel Mood Scale, and visual analog scales (VAS). Physiological indicators of mental fatigue included electroencephalography (EEG), and heart rate variability (HRV). Subjective ratings of mental fatigue increased from pre to 0-min post in all-treatments, but not the documentary (p < 0.05). Subjective fatigue (VAS) remained higher (p < 0.05) than pretreatment values for 20-, 50-, and 60-min following the PVT, Stroop, and AX-CPT respectively. The cognitively demanding tasks had unclear effects on 3-min PVT, EEG, and HRV assessments. Tasks requiring response inhibition appear to induce fatigue for longer durations than a simple vigilance task. Simple VAS appear to be the most practical method for assessing mental fatigue.

Keywords:

• Assessment
• neuropsychology
• psychophysiology

Additional information

Notes on contributors

Mitchell R. Smith

Mitchell R. Smith is a lecturer in the Faculty of Science at the University of Newcastle, Australia. His research interests include the influence of mental fatigue on athletic performance, with an emphasis on team sports.

Rifai Chai

Rifai Chai in Faculty of Science, Engineering and Technology at Swinburne University of Technology, Australia. His research interests include human-computer interfaces and artificial intelligence.

Hung T. Nguyen

Hung T. Nguyen is Pro Vice-Chancellor for Faculty of Science, Engineering & Technology at Swinburne University of Technology. His research interests include biomedical engineering, artificial intelligence, advanced control and neurosciences.

Samuele M. Marcora

Samuele M. Marcora is a Professor in the Department of Biomedical Science and Neuromotor Sciences (DIBINEM) of the University of Bologna (Italy) and at the School of Sport and Exercise Sciences of the University of Kent (UK). His research investigates the psychobiology of endurance performance, fatigue, and physical activity.

Aaron J. Coutts

Aaron J. Coutts in a Distinguished Professor in Sport and Exercise Science at the University of Technology Sydney (UTS). His research focus is on issues relating to optimising health and performance in athletes.