Auditory stimulation with music intensifies cardiac autonomic responses to a mental task

Background The literature is ambiguous as to whether exposure to relaxing classical music before mental arithmetic overload tests can affect cardiac autonomic regulation. Objectives To evaluate the effects of musical auditory stimulation on cardiac autonomic regulation after a mental arithmetic test. Methods This prospective study was conducted with 28 healthy male students aged 18–25 years. In the first evaluation protocol, participants rested for 10 min with the earphone turned off. After this period, participants had 5 min to perform the mental arithmetic overload test and 5 min of rest post test. In the second protocol, the participant was exposed to musical auditory stimuli for 10 min before completing the mental arithmetic overload test. Geometric indices [triangular interpolation of RR intervals ( TINN ); triangular index of RR intervals ( RRtri ); and Poincaré plot ratios SD1 , SD2 and SD1 / SD2 ] of heart‐rate variability ( HRV ) were evaluated before, during and after the mental arithmetic test. The S hapiro– W ilk test was used to verify data normality. For parametric variables, repeated measures ANOVA was used followed by the B onferroni test. For non‐parametric distributions, F riedman's test was used followed by the D unn's post‐test. Results The mental task did not change HRV under control conditions. Following exposure to musical stimuli, there was significant ( P <0.05) cardiac autonomic changes, derived from RRtri , TINN and SD2 indices, which decreased during and after the mental arithmetic test. Conclusions We evaluated the acute effects of classic baroque musical auditory stimulation on cardiac autonomic regulation after a mental task in 28 male volunteers. The findings suggest auditory stimulation increases cardiac autonomic sensitivity induced by mental tasks.