[A hemodynamic comparison of cardiovascular stress responses during mental arithmetic and reaction time tasks]

Effect of allocating attention to aversive events on cardiovascular responses and event-related potentials in a dual-task paradigm

This study investigated the effect of the allocation of attentional resources on event-related potentials (ERPs) and cardiovascular responses during a dual-task situation in which an avoidance task and a reward task were coupled. For the avoidance task, subjects were able to avoid an aversive shock that followed a target tone by pressing a button. For the reward task, subjects were asked to detect the direction of an arrowhead presented on the display screen and were rewarded for rapid, accurate reaction times. The 31 participants were divided into two groups based on their subjective impression of attention distribution between the avoidance and the reward task. Participants in the first group were motivated more by the avoidance task (AVD; n=18), whereas those in the second group were motivated more by the reward task (RWD; n=13). The ERPs to non-target and target tones, ECG, systolic blood pressure (SBP), and diastolic blood pressure (DBP) were analyzed in the dual-task situation. The results indicated that the amplitudes of N1 to target and non-target tones, and of N2 to the target tone were larger in the avoidance (AVD) group than they were in the reward (RWD) group. The AVD group had higher blood pressure than did the RWD group during the aversive periods. However, there were no significant group differences in the mean RTs for avoidance and reward tasks, and participants in both groups reported similar subjective evaluations of their mental workloads. The results suggest a vigilant coping strategy that selectively focus attention to threatening information as illustrated by N1 and N2 changes may intensify psychophysiological arousal under stress.

Mirror Tracing and the Provocation of Vascular-Dominant Reaction Pattern Through Heightened Attention

Abstract After a hint from Lang et al.'s (1997) defence cascade, researchers considered cognitive process experienced when encountering mental stress to be composed of four elements: (serially) first attention (Attent), second unpleasant affect (UnplAff) and sometimes pleasant affect (PlAff), and third cognitive coping (CogCop). The present study investigates the effect of each cognitive element on the provocation of the well-known vascular-dominant reaction pattern during mirror tracing: elevation of mean blood pressure mainly because of increases in total peripheral resistance. Twenty-four male students first underwent four computer-simulated mirror-tracing practices of 3 min each, then a 7 min adaptation followed by a 3 min baseline, and further four kinds of actual mirror tracing trials (Attent, UnplAff, PlAff, and CogCop) of 3 min each. Results on the cardiovascular measures indicated that every mirror-tracing trial indisputably provoked the vascular-dominant reaction pattern. An alpha-adrenergic vascular sympathetic activation was heightened. Self-report measures on the four cognitive elements suggested that heightened Attent seemed to contribute to provoking the reaction pattern. Although the UnplAff and PlAff trials had an active coping feature in a narrow sense, they could not provoke the cardiac-dominant reaction pattern. Differences in task difficulty among the mirror tracings could not explain the results. The implications of these results are discussed in order to better understand cardiovascular hemodynamics during mental stress.