Inhibition control and cardiac reactivity in young and middle-aged adults

This study investigated the dynamics of cardiac reactivity during the performance of three cognitive tasks involving various levels of inhibition control in young and middle-aged adults. Twenty-eight young adults (18-27 years) and twenty-two middle-aged adults (55-65 years) performed variations of a flanker task involving neutral, congruent, incongruent and No-Go trials, while their cardiovascular parameters (heart rate, blood pressure, cardiac Pre-Ejection Period: PEP) were recorded. Specifically, each task was repeated twice and we examined variations of PEP and PEP reactivity as a function of time on task and task repetition. The results revealed that PEP reactivity was shown to be a transient phenomenon, decreasing both over the course of each task (only significant during the first minute) and across repeated sessions. PEP reactivity was related to cognitive load, albeit not in a linear fashion, but was not clearly related to cognitive performance. Age-related effects were demonstrated for cognitive performance as well as resting and task PEP values, but not for PEP reactivity. It is concluded that PEP reactivity showed characteristics of habituation and sensitization that are discussed in light of the theory of dual-process habituation and the model of effort and cardiovascular response.