The Roles Of Cognitive Load and Appraisal of Task Difficulty In Predicting Subjective Fatigue and Subsequent Task Disengagement

Central fatigue refers to an inability to sustain mental or physical performance in self-initiated tasks and an increased perception of effort (Chaudhuri & Behan, 2000), suggesting that fatigue results from a mismatch between the perceived resources needed to initiate a task and the availability of cognitive resources available to complete it. Consequently, fatigue may be considered a “stop-emotion” to preserve cognitive resources, resulting in task disengagement (Meijman, 2000). This study investigated: 1) the role of perceived cognitive resources in the development of mental fatigue by manipulating the task demands and appraisals of task difficulty, and 2) the subsequent effect of fatigue on task engagement. Fatigue increased and cognitive resources decreased with time on task, rather than as a result of the task demands × instruction of task difficulty interaction. Increases in fatigue did not predict measures of engagement in almost all cases. Implications and suggestions for future research are discussed.