Michael Persinger wrote quite a lot about how geological effects, magnetic field distortions, can produce all kinds of odd perceptions, including globular light effects that move or blink-out suddenly. I'm not sure if these are demonstrable or have been recorded in some way
Persinger and his transients generated a lot of interest. Unfortunately his theories regarding geological stresses and magnetic field effects have been very difficult to test in the field. No predictive validity has been found AFAIK (e.g., "There are known geological stresses in this area, so we'll see more reports of ghosts/ UFOs/ orbs").
Like the proposed links between geomagnetic storms and, well, pretty much every aspect of human life (discussed on this thread,
Claim: Fluctuations in Earth's magnetic field (geomagnetic storms) causes a myriad of different health problems) the majority opinion at present seems to be that the magnetic fields invoked by Persinger are much too weak to directly influence any part of the brain or sense organs.
External Quote:
Persinger considered the temporal contiguity of reports of unidentified luminous phenomena preceding local seismicity due to
injections of fluids a
quasi-experimental support for the hypothesis. Alternative models, developed by Persinger and David Vares, were quantified for interaction between quantum values and specific magnitude earthquakes,
global climate variations, interactions with
population densities, discrete energies as mediators of disease, and processes by which human cognition could be covertly affected by
Schumann Resonances and geomagnetic activity.
https://en.wikipedia.org/wiki/Michael_Persinger. Study enough datasets, you might find a chance correlation sooner or later.
(To be honest, I don't know what some of the phrases above are meant to mean, but maybe it's the Wikipedia author's fault).
To demonstrate that magnetic fields could influence human cognition, Persinger experimented with the "Koren helmet", widely referred to as the "God helmet"
https://en.wikipedia.org/wiki/God_helmet. Persinger claimed that very weak fluctuating magnetic fields, generated in a helmet and placed over the temporal regions of the head, caused the wearer to sense "a presence" or have other strange sensations or paranormal/ spiritual experiences.
There was extensive media and (for a while) scientific interest. And attempts to replicate the experiment.
A Swedish team borrowed the helmets, and protocols, actually used by Persinger and Koren;
Granqvist, P., Fredrikson, M., Unge, P. et al.,
"Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields",
Neuroscience Letters 379 (1), 2005
https://www.sciencedirect.com/science/article/abs/pii/S0304394004013473?via=ihub.
From their abstract:
External Quote:
Transcranial magnetic stimulation (TMS) with weak (micro Tesla) complex waveform fields have been claimed to evoke the sensed presence of a sentient being in up to 80% in the general population. These findings have had a questionable neurophysiological foundation as the fields are approximately six orders of magnitude weaker than ordinary TMS fields.
...We found no evidence for any effects of the magnetic fields, neither in the entire group, nor in individuals high in suggestibility. Because the personality characteristics significantly predicted outcomes, suggestibility may account for previously reported effects. Our results strongly question the earlier claims of experiential effects of weak magnetic fields.
External Quote:
Crucially, Granqvist and colleagues argue, entirely correctly, that the magnetic fields generated by the God helmet are far too weak to penetrate the cranium and influence neurons within. Transcranial magnetic stimulation (TMS) uses field strengths of around 1.5 tesla in order to induce currents strong enough to depolarise neurons through the skull and cause them to fire. Persinger's apparatus, on the other hand has a strength of around 1 millitesla. To give you some context, that's 5000 times weaker than a typical fridge magnet. Granqvist argues that there is simply no way that this apparatus is having any meaningful effect on the brain...
"Neuroscience for the soul", Craig Aaen-Stockdale, 04 July 2012,
The Psychologist
https://www.bps.org.uk/psychologist/neuroscience-soul
One published study supported Persinger's findings, Tinoca, C.A.,, Ortiz, J.P.L.,
"Magnetic Stimulation of the Temporal Cortex: A Partial "God Helmet" Replication Study",
Journal of Consciousness Exploration & Research 5 (3), 2014. Only 20 subjects, their religious faith is listed: Curiously 4 are listed as "spiritualist" or "tendency to spiritualism" (there is a separate descriptor of "spiritualistic") and only 6 Catholic (including a "Nonpracticing Catholic. Spiritualistic"). I suspect this was not a representative sample of the Brazilian population, unless the researchers recruited people attending seances.
https://jcer.com/index.php/jcj/article/viewFile/361/386
A perhaps unexpected problem for Persinger's Koren helmet findings is that similar-ish findings of strange experiences have been made by teams using the helmet, who didn't actually turn it on.
And it turns out you can get the same findings if you use a completely sham placebo helmet but tell the subject it's a "God helmet", and you've turned it on:
"An EEG Study on the Effects of Induced Spiritual Experiences on Somatosensory Processing and Sensory Suppression",
Michiel van Elk,
Journal for the Cognitive Science of Religion 2 (2), 2015
https://journal.equinoxpub.com/JCSR/article/view/10693;
"Exceptional Experiences Following Exposure to a Sham "God Helmet": Evidence for Placebo, Individual Difference, and Time of Day Influences", Simmonds-Moore,C., Rice, D., O'Gwin, C., Hopkins, R.,
Imagination, Cognition and Personality 39 (1) 2017
https://journals.sagepub.com/doi/10.1177/0276236617749185
External Quote:
Using kit and code borrowed from Persinger himself, Granqvist and colleagues could not reproduce his effects. They did, however, show that subjects' scores correlated with their suggestibility. In a biting critique they argue that Persinger's experiments weren't properly double-blinded, subjects' expectations were biased before the experiments and that the items on Persinger's questionnaire were arbitrary and idiosyncratic (Granqvist et al., 2005).
"Neuroscience for the soul", link as above.
The findings that placebo helmets "induce" strange perceptions as effectively as a Koren helmet strongly support Granqvist et al.'s concerns about Persinger's double-blinding.
Persinger's specific areas of interest- geological stresses and (very weak) magnetic fields having profound effects on human cognition, probably via the temporal lobes- haven't really progressed much in recent years (Persinger died in 2018), and are arguably no longer seen as mainstream science. It must be unlikely that magnetic influence on the temporal lobes explain orbs.