Workload stress and stimulus-response compatibility: Effects on response latencies in a choice reaction time task

Stimulus-response compatibility effects refer to the phenomenon where certain mappings of stimuli to responses produce faster and more accurate responses than others. Increased latencies are attributable to a decreasing attentional resource pool as well as stress symptoms. The primary purpose of this study was to examine the effects of levels of workload stress through the addition of a dual task on the accuracy and speed of choice reaction time (CRT) performances varying in spatial and anatomical stimulus-response compatibility. A secondary purpose was to determine if there was association between increased RT latencies and indices of stress, i.e., heart rates and self-reported anxiety scores. Fifty undergraduate students were randomly assigned to one of the two groups: the single-task condition and the dual-task condition. Each participant completed 160 trials that were spread out across four different stimulus-response compatibility (SRC) conditions that were quasi-randomly presented. Dependent variables included latencies in choice reaction time (CRT), error scores, average heart rates, and pre- and post-scores of the modified POMS. Results supported the previous findings of S-R compatibility. The dual task consistently produced longer latencies than the single task condition and more direct mappings stimuli to response led to faster latencies. In addition, a sex effect and crossed-hand effect were identified. Males were faster and more accurate than females when the spatial S-R compatibility was low and workload stress was high. The hypothesized connection between increased response latencies and stress symptoms was not identified suggesting that the increased response latencies were attributable more to a decreasing attentional resource repertoire than to the interference of increased sympathetic output.