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Effect of visual and auditory stimuli on heart rate

This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License http: This article has been cited by other articles in PMC. Abstract Acoustic stimulus can modulate the Autonomic Nervous System. However, previous reports on this topic are conflicting and inconclusive.

In this study we have shown, how rotating acoustic stimulus, a novel auditory binaural stimulus, can change the autonomic balance of the cardiac system.

We have used Heart rate Variability HRVan indicator of autonomic modulation of heart, both in time and frequency domain to analyze the effect of stimulus on 31 healthy adults. Post stimulus greater increment of SD12 with higher lag numbers of M beat to beat intervals, when compared to pre stimulus values, resulted in increased curvilinearity in the SD12 vs.

From these characteristic responses of the heart after the stimulus, it appears that rotating acoustic stimulus may be beneficial for the sympathovagal balance of the heart. A proper balance of the sympathetic and parasympathetic divisions of ANS is required for optimum functioning. Sensory inputs, like auditory stimulus, can have a wide range of psychological and hemodynamic effects by modulating the ANS.

Harmonic auditory stimulus has been shown to relieve stress and related ailments [ 45 ].

Background:

Moving sound produced by the sequential excitation of a mono source through several speakers in a free field, can generate a specific activity in the brain [ 6 ].

It evokes a magnetic response in parietal and temporal cortex, which is not seen with a stationary sound stimulus [ 78 ].

  • Comparison between auditory and visual simple reaction times;
  • SD1 is the length of the semi-minor axis of the ellipse and SD2 is the length of the semi-major axis [ 18 ];
  • Preparing the heart, eye, and brain;
  • The present results obtained in the visual WS group do not allow one to determine whether the visual WS negatively influenced responsivity;
  • The behavioral effects of visual and auditory WS were compared using the mixed-block design and choice RT task;
  • An information-processing account of its origins and significance.

In order to facilitate such experimentation using moving sound we have previously engineered a binaural rotating acoustic stimulus [ 9 ].

Heart rate variability HRVa measure of the beat to beat fluctuation of the heart rate, is related to the functioning of the ANS. Due to its noninvasive nature and convenience of measurement, HRV is often used to assess the influence of ANS on cardiac function [ 1011 ].

  • Effects of exercise on cognitive processes;
  • The comparison of the facilitatory effects produced by the auditory WS and visual WS represented in each case by the difference between the RTs in the WS-present and WS-absent trials would indicate the relative ability of the two modalities to mobilize the alertness process.

Linear methods, analyzed in both time and frequency domain have been traditionally used to study HRV [ 1213 ]. However, such methods tend to ignore the complex and nonlinear nature of the cardiac system and potentially overlook vital information. In this paper, we have studied the effect of rotatory acoustic stimulus on ANS by measuring HRV using linear and nonlinear methods.

Effect of Rotating Acoustic Stimulus on Heart Rate Variability in Healthy Adults

Only sinus beats were selected for analysis. In the linear analysis of HRV, the mean heart rate decreased from 83. The decrease was more in subjects with higher baseline heart rate. Both the standard deviation SD of R- R interval i. SD value changed from 23.

SD1 is the length of the semi-minor axis of the ellipse and SD2 is the length of the semi-major axis [ 18 ]. In this analysis, with an increase in the lag number the plot became more scattered with an increment in the length and width of the plot Fig. This effect was more pronounced post stimulation.

  1. Tables 1 and 2 in the Appendix show the mean RTs in all of the conditions in the first and second sessions for each group of participants.
  2. The conclusions of these two studies should be applicable to both visual WS and WS of other modalities such as audition. The possibility that it occurred only in the WS-absent trials as a consequence, for example, of some confusion generated by the absence of the reference event represented by the WS in the trials sequence does not have any empirical support.
  3. Journal of General Psychology, 123, 105-114. A computer controlled by a protocol developed using MEL Professional v.