Long-Term Study of Heart Rate Variability Responses to Changes in the Solar and Geomagnetic Environment

Abstract

This long-term study examined relationships between solar and magnetic factors and the time course and lags of autonomic nervous system (ANS) responses to changes in solar and geomagnetic activity. Heart rate variability (HRV) was recorded for 72 consecutive hours each week over a five-month period in 16 participants in order to examine ANS responses during normal background environmental periods. HRV measures were correlated with solar and geomagnetic variables using multivariate linear regression analysis with Bonferroni corrections for multiple comparisons after removing circadian influences from both datasets. Overall, the study confirms that daily ANS activity responds to changes in geomagnetic and solar activity during periods of normal undisturbed activity and it is initiated at different times after the changes in the various environmental factors and persist over varying time periods. Increase in solar wind intensity was correlated with increases in heart rate, which we interpret as a biological stress response. Increase in cosmic rays, solar radio flux, and Schumann resonance power was all associated with increased HRV and parasympathetic activity. The findings support the hypothesis that energetic environmental phenomena affect psychophysical processes that can affect people in different ways depending on their sensitivity, health status and capacity for self-regulation.

Figure 1

Environmental data activity across the study period. There was a large increase in the Kp and Ap indexes that occurred on July 14^th, which resulted from a coronal mass ejection that hit the earth’s magnetic field at approximately 1800 UT that day.

Figure 2

Two data series representing an environmental time series and a HRV time series. The environmental signals position at lag 0 (upper series) is as it occurred relative to the HRV signal. The middle trace shows the same environmental data series after shifting it in time by 10 hours. In this example, correlations between the HRV and environmental data would be higher at lag 10 than at lag 0 indicating a delayed physiological response to the external environmental signal.

Figure 3

The correlations between HRV variables and changes in measures of solar activity and cosmic rays across the forty-hour analysis time period.

Figure 4

The correlations between HRV variables and changes in Schumann Resonances and ULF power across the forty-hour analysis period.

Figure 5

The correlations between HRV variables and changes in measures of magnetic field disturbance across the forty-hour analysis time period.