CARDIOVASCULAR AND ENDOCRINE RESPONSES TO EXPERIMENTAL STRESS - EFFECTS OF MENTAL EFFORT AND CONTROLLABILITY

The objective of the study was ro investigate the unique and interacti ve effects of the controllability of a task and mental effort required by that task on cardiovascular and endocrine reactivity, when both we re manipulated independently. A 2 x 2 factorial design was used, with two levels of mental effort and two levels of control. Twenty-four hea lthy male subjects participated in each experimental condition. Heart rate, blood pressure, catecholamine and cortisol responses were determ ined. High effort lead to greater increases in heart rate, blood press ure and norepinephrine levels. Uncontrollability lead to higher cortis ol, blood pressure and norepinephrine responses. In addition, there wa s an effort x control interaction effect oil the diastolic blood press ure response. In conclusion, effort has clear sympathetic effects, whe reas control influences both the sympathetic nervous system and the re lease of cortisol. Having control seems to be most beneficial in high effort situations, at least with respect to sympathetic reactivity. (C ) 1998 Published by Elsevier Science Ltd. All rights reserved.