Travis’ Note: Today’s post comes from Dr Patrice Brassard, and and has been adapted from a recent paper from his research team titled Mental Work Stimulates Cardiovascular Responses through a Reduction in Cardiac Parasympathetic Modulation in Men and Women. You can find out more about Dr Brassard at the bottom of this post.
Mental work stimulates cardiovascular functions in healthy adults and a reduction in cardiac parasympathetic modulation could be one mechanism involved in such a response. The influence of sex on these cardiovascular responses remains ambiguous. The aim of the study was to evaluate cardiovascular impacts of mental work in healthy individuals and whether sex influences cardiovascular responses induced by mental work.
What did we do?
The impact of a 45-min reading and writing session compared to a control condition (subjects were comfortably sitting in an arm chair), on blood pressure, heart rate, and heart rate variability, was evaluated in 44 healthy adults (22 men and 22 women). The influence of sex on those variables was then evaluated.
What did we find?
Diastolic blood pressure and mean arterial pressure, heart rate and low frequency/high frequency ratio were higher, while global heart rate variability and cardiac parasympathetic activity were lower during mental work vs. the control condition in the whole sample. During both experimental conditions, heart rate was higher, while blood pressure and several variables of heart rate variability were lower in women compared to men. The intensity of the cognitive demand (evaluated by the reaction time to a secondary task and the NASA Task-Load Index) and its influence on cardiovascular variables were comparable between men and women.
What’s the take-home message?
The results of this study suggest that an experimental mental work condition consisting of a 45-min period of reading and writing a summary, as other types of mental work (such as arithmetic) utilized in the laboratory, can modulate cardiovascular responses in healthy young adults through a reduction in cardiac parasympathetic activity. In addition, these results do not support an influence of sex on cardiovascular responses induced by the cognitive demand, at least when its intensity is comparable between the sexes.
About the author: Dr Patrice Brassard is an assistant professor of Kinesiology at Université Laval in Quebec city, Canada. His main research interests are the integration of cardiopulmonary and cerebrovascular physiology in patients with diabetes at rest and during exercise, and the impact of mental work on the cardiovascular system in healthy subjects. You can find him on his blog Le Physiologiste or @Pat_Brassard.
Emilie Perusse-Lachance, Angelo Tremblay, Jean-Philippe Chaput, Paul Poirier, Normand Teasdale, Vicky Drapeau, Caroline Senecal, & Patrice Brassard (2012). Mental Work Stimulates Cardiovascular Responses through a Reduction in Cardiac Parasympathetic Modulation in Men and Women Bioenergetics: Open Access : http://dx.doi.org/10.4172/2167-7662.S1-001