The effect of noise interference, type of cognitive stressor, and order of task on cardiovascular activity

In the search for reliable, easily applicable mental stressors many researchers have investigated the propensity of mental arithmetic and Stroop color discrimination tasks to elicit a physiological stress response; some researchers have added noise interference with the expectation of larger response magnitudes. The present study investigates a number of previously untested questions by directly comparing cardiovascular responses to mental arithmetic or the Stroop task with and without noise interference in a sample of 66 young adults. Half of all subjects were exposed to the additional noise interference, all subjects responded to both types of mental stressors. Blood pressure responses did not discriminate among the stressors but noise interference consistently augmented heart rate responses during mental arithmetic. Response to the second, repeated stressor was associated with highly significant response habituation effects for blood pressure. Furthermore, when mental arithmetic was presented first, both tasks elicited comparable and large responses; when the Stroop test was presented first both tasks triggered smaller responses but of comparable magnitude. Subjective evaluations of the stressors were not predictive of overall physiological response.