Hypnotic manipulation of effort sense during dynamic exercise: cardiovascular responses and brain activation

TLDR

The study aimed to use hypnosis to alter perceived effort during cycling and assess activation of cortical areas linked to cardiovascular control. Six highly hypnotizable volunteers performed constant‑load cycling under three hypnotic conditions (level, downhill, uphill) while RPE, heart rate, blood pressure, and regional cerebral blood flow were measured and compared by ANOVA. Downhill hypnosis lowered perceived exertion and left insular/anterior cingulate blood flow without affecting heart rate or blood pressure, whereas uphill hypnosis raised perceived exertion, heart rate, blood pressure, and increased right insular and thalamic activation; thus, heightened effort sense activates insular and thalamic regions and elevates cardiovascular responses, but reduced effort sense does not lower cardiovascular responses below metabolic requirements.

Abstract

The purpose of this investigation was to hypnotically manipulate effort sense during dynamic exercise and determine whether cerebral cortical structures previously implicated in the central modulation of cardiovascular responses were activated. Six healthy volunteers (4 women, 2 men) screened for high hypnotizability were studied on 3 separate days during constant-load exercise under three hypnotic conditions involving cycling on a 1) perceived level grade, 2) perceived downhill grade, and 3) perceived uphill grade. Ratings of perceived exertion (RPE), heart rate (HR), blood pressure (BP), and regional cerebral blood flow (rCBF) distributions for several sites were compared across conditions using an analysis of variance. The suggestion of downhill cycling decreased both the RPE [from 13 ± 2 to 11 ± 2 (SD) units; P< 0.05] and rCBF in the left insular cortex and anterior cingulate cortex, but it did not alter exercise HR or BP responses. Perceived uphill cycling elicited significant increases in RPE (from 13 ± 2 to 14 ± 1 units), HR (+16 beats/min), mean BP (+7 mmHg), right insular activation (+7.7 ± 4%), and right thalamus activation (+9.2 ± 5%). There were no differences in rCBF for leg sensorimotor regions across conditions. These findings show that an increase in effort sense during constant-load exercise can activate both insular and thalamic regions and elevate cardiovascular responses but that decreases in effort sense do not reduce cardiovascular responses below the level required to sustain metabolic needs.