My head hurts: Inducing and controlling mental fatigue


Mental fatigue is a psychobiological state induced by sustaining cognitive attention on one, or multiple, tasks (van der Linden et al., 2003). Mental fatigue has a negative effect on both cognitive and physical performance (Marcora, 2009). The quantifiable effect of mental fatigue on behaviour, performance, and mood is also still under investigation, and as of yet there is no gold standard for inducing the state and measuring it. The purpose of this investigation was to ascertain the effect of the AX-CPT cognitive task, and a common neutral control condition on mental fatigue. Forty-two participants (mean age = 21; males = 16,) were assigned either the experimental (AX-CPT) condition, or the control (neutral documentary) condition, each lasting 90 minutes. Mental fatigue was measured via the Brunel Mood Scale pre and post-test. Participants also completed a wall sit to voluntary exhaustion post-test. Results indicated a significant interaction of time and group (F(1, 40) = 14.965, p = 0.05), with participants in the experimental group reporting significantly higher levels of post-test mental fatigue (M = 11.71, SD = 3.6) than the control group (M = 5.81, SD = 3.61). A significant difference in wall sit times was also reported, with the experimental group performing significantly worse (M = 123.33, SD = 42.85) than the control group (M =171.05, SD = 90.51). Conclusions include that the AX-CPT is a valid method for inducing mental fatigue, however some concerns regarding the control condition arose. Many participants in the control group expressed elevated levels anger and tension, indicating that it may not be the best approach for the population.