A visual-visual dual task was designed to test the effect of the thermal environment on dual task performance and attention allocation. The temperatures selected for testing were 20 and 35°C Wet Bulb Globe Temperature (WBGT) in experiment 1 and 25, 30 and 35°C Wet Bulb Globe Temperature (WBGT) in experiment 2. In experiment 1, 34 volunteers were randomly assigned to one of the two temperature conditions. A variable representing accuracy on both tasks was coded such that a correct response was assigned only if the participant answered correctly on both tasks. In experiment 2, 42 volunteers were randomly assigned to one of three temperature conditions and instructed vary the amount of attention allocated to each task. Individual differences in single task performance were controlled by equating the baselines of single task performance. Once individual differences in single task capacity were controlled, statistically significant differences in performance were demonstrated. Mean accuracy was computed over a one-hour testing period in each temperature condition. Participants’ mean accuracy in the 35°C condition (38.18%) was substantially less than in the 20°C condition (50.88%). Further, statistically significant differences in performance were detected: in the ability to equally divide attention, effectively allocate attention, and in the relative divided attention cost under thermal stress.
Chase, Bradley; Karwowski, Waldemar; Benedict, Michael E.; and Queseda, Peter M.
"Effects of Thermal Stress on Dual Task Performance and Attention Allocation,"
Journal of Human Performance in Extreme Environments: Vol. 8
, Article 1.
Available at: http://docs.lib.purdue.edu/jhpee/vol8/iss1/1