Relationships between the type A behavior pattern and phasic heart rate responses during a reaction time task

Type A and B college students performed a signalled reaction time task with a 17-s fixed preparatory internal (PI) while heart rate was recorded. The analysis of the first half of the PI indicated a triphasic heart rate response (deceleration-acceleration-deceleration) to the warning signal, followed by a return toward baseline. No group differences were found. During the latter half of the PI, the Type B subjects exhibited a time-locked heart rate deceleration which reached its maximum at the second immediately prior to the onset of the imperative stimulus. The Type A subjects exhibited maximum deceleration earlier in the PI. These findings are consistent with previous work indicating that Type A's have difficulty maintaining their attention over relatively long PI's of reaction time tasks.