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Bioelectromagnetism

 

It is speculated that SR and ELF background felds played an important role in the evolution of biologi­

cal systems and are used by them as a means of stochastic synchronization for various biorhythms (Cole

and Graf, 1974). Te SR frequencies are mainly controlled by the Earth’s radius, which has remained

constant over billions of years (Morente et al., 2003). Terefore, these frequencies can play a special role

for the regulatory pathways of living organisms, the SR providing a synchronization reference signal, a

Zeitgeber (time giver) (Cherry, 2002).

It has been clarifed that the frst SR frequency is 7.83 Hz, with a day/night variation of around

± 0.5 Hz (Sentman, 1995). Te higher frequencies are ~14, 20, 26, 33, 39, and 45 Hz due to frequency-

related, ionospheric propagation loss (Schumann, 1952; Bliokh et al., 1980; Sentman, 1995), all of which

closely overlay with α (8–12 Hz), β (12–30 Hz), and γ (30–100 Hz) brain waves (Cherry, 2002). Te similar­

ity of the EEG with the SRs was recognized early on, and the ability of the EEG rhythm to synchronize

with SR activity was observed (König et al., 1981).

Altered EEG rhythms in response to changing the GMF have been observed with ELF magnetic oscil­

lations (~3 Hz) having a sedative efect (Belov et al., 1998). It has also been demonstrated that autonomic

nervous system activity not only reacts to shif in the geomagnetic and solar activity, and it can also

synchronize with rhythms in the time-varying MFs related to the SR and the GMF-line resonances

(McCraty et al., 2017; Timofejeva et al., 2017). Te SR and the EEG have been examined in a group of

participants over 6 weeks, and it was found that the EEG changes during the daily cycle were similar to

variations in the SR (Pobachenko et al., 2006). Te highest correlations between SR and EEG were found

when the magnetic activity was increased. SR and EEG activities have also been studied in real-time

and it has been shown that many of the SR frequencies can be observed in the power spectrums of most

EEG activity (Saroka and Persinger, 2014; Persinger and Saroka, 2015). It has also been shown that the

spectral profles within the EEG activity displayed recurrent transient segments of real-time coherence

(synchronization) with the frst three resonant frequencies of the SR (7–8 Hz, 13–14 Hz, and 19–20 Hz).

Tese fndings suggest that under certain conditions variables afecting the SR parameters (such as solar

wind) may afect EEG activity, such as modifcations of perception and dream-related memory consoli­

dation (Persinger and Saroka, 2015).

Hainsworth (1983) noted that the average frequency at which there is minimum power circulating in

the Earth-ionosphere cavity is the same frequency as the dominant human brain-wave rhythm—10.5 Hz.

Cannon and Rycrof (1982) and more recently Schlegel and Füllekrug (1999) reported the efects on SR

produced by ionospheric disturbances induced by solar activity. “Solar Proton Events (SPEs)” have been

found to decrease the frequency of the SR modes. Roldugin et al. (2001) found that, during the peak

of four SPEs, the frequency of the frst SR mode decreased by about 0.15 Hz, as measured in the Kola

Peninsula of Russia. Roldugin et al. (2001) also reported an increase in the frequency and a resonance

bandwidth decrease of about 0.2 Hz of the frst Schumann mode as a result of a very intense solar X-ray

burst. Any change in the SR signals due to ionospheric disturbances will be superposed on the diurnal

(i.e., circadian) variations due to solar heating and ionization on the dayside. As visual and auditory

stimulation produce biological efects, Hainsworth (1983) argued that EM signals at frequencies in the

brain wave spectrum can be expected to produce biological efects too. Hainsworth (1983) also argues

that the association with the human α-rhythm near 10 Hz with the frequency of minimum energy in the

SR spectrum and, therefore, of minimum natural interference is unlikely to be a coincidence.

Hainsworth (1983) suggested that other factors that could afect the apparent connection between

geophysical parameters and biological efects are links with geographical considerations. For instance,

wind eddies carrying ionized air can produce oscillatory signals in the range of 3–6 Hz. Tese could be

associated with thunderstorm activity or with winds such as the Fohn wind in Austria and could have

localized biological efects.

It has been shown that the intensity of the SR signals is afected by the air temperature. Williams (1992)

demonstrated a positive correlation between the monthly means of the tropical surface-air-temperature

anomaly and the MF amplitude for the fundamental SR mode. A 2 K change in temperature was shown