Cognitive function during exertional heat stress assessed using traditional and serious game technology

Abstract

Firefighting is a physically demanding occupation requiring intermittent bouts of work resulting in increased levels of cardiovascular and thermal strain, while making decisions requiring higher order cognitive abilities e.g. working memory, sustained attention, reaction time, spatial awareness, and information processing. These activities can take place in dangerous conditions with elevated temperatures imposing external stressors on physiological and cognitive function. Previous research has examined the impact of heat stress on cognitive function in general, but the specific influence on firefighters wearing personal protective equipment (PPE) and self-contained breathing apparatus (SCBA) is not well understood. Specific domains of cognitive function can be assessed using computer-based neuropsychological testing batteries, such as the Cambridge Neuropsychological Automated Testing Battery (CANTAB). The CANTAB automatically records the response measures for each test and provides consistent feedback in between trials. Although the CANTAB is well established the cognitive domains it tests may not adequately capture the complexity of the specific decision making required of firefighters while on-duty. The use of serious game technology provides a possible solution to develop a more ecologically valid assessment tool capable of evaluating the specific decision making tasks required of firefighters at an emergency scenario. Thus, the current thesis aimed to evaluate the effects of exercise-induced heat stress on cognitive function in firefighters using the CANTAB testing battery and a recently developed serious game simulating the decision making tasks required of firefighters in a two-storey residential fire while walking on a treadmill. Additionally, the reliability of repeated CANTAB administrations during treadmill walking was measured and found to have reasonable overall reliability. Decrements in cognitive function (working memory and executive function were observed at a core temperature of 38.5°C and restored following an active cooling recovery protocol. However, when decision making was evaluated using the serious game scenario, task specific performance deficits were not seen during treadmill walking but impairment in memory recall was found following the active cooling recovery protocol. These findings provide fire service personnel with information regarding the cognitive implications of heat stress and the potential use of serious games to evaluate and train cognitive function during exposure to environmental stressors.