Archive for the ‘Parapsychology’ Category

EEG, Hans Berger, and psychic phenomena

Monday, August 2nd, 2010

EEG, Hans Berger, and psychic phenomena:

[Hans Berger, the inventor of EEG] was a big believer in psychic phenomena: namely telepathy. He believed that there was an underlying physical basis for mental phenomena, and that these mental processes—being physical in nature—could be transmitted between people. Thus, in order to show that psychic phenomena exist, Berger sought to show the nature of the underlying physical processes of thoughts and emotions.

See, if you’re hoping that the existence of telepathy, say, would imply that the mind cannot be reduced to the physical brain, you’re quite mistaken. The real ability to communicate with the dead would indeed imply that separability; but telepathy itself, and psychic phenomena in general, even if they existed, could just as well be purely physical phenomena.

The greatest hope for the idea of consciousness being separable from the physical brain is actually testimony like that of (gak) Ken Wilber, of being fully conscious while flatlining on an EEG, after years of deep meditation. (It would not surprise me at all if the Wilber-admiring Sam Harris got his “not at all sure that consciousness can be reduced to brain function” hope from exactly that phenomena.) But even there, the brain could still be producing EM waves, just at frequencies much higher than anybody has bothered to measure. (Valerie Hunt did studies of the aura utilizing a similar idea.) Or the witnessing, self-aware consciousness of each one of us could be the product of chemicals in the brain, thus not showing up on an EEG.

[Berger] initially studied blood flow and used it as an index to measure “P-energy” (psychic energy) associated with mentation and feelings. Of course, this being prior to the advent of neuroimaging, there was no way to actually measure cerebral blood flow from a person. So Berger made a leap. The brain receives so much blood from the heart (about 20% of the cardiac output), that the brain pulses with each heartbeat (you can check out a video of the human brain pulsing here). Parents with newborns might even be able to notice this phenomenon if they lightly touch the soft spot at the top of their baby’s head.

Ooh, Brahmarandhra alert!

So the only reason Berger saw the EEG signal in the first place was because he was working with the same patients he was trying to record brain pulsations from. And the only reason he was interested in these brain pulsations was to try and tie cerebral activity (blood flow) to mental states to show that thoughts have a physical basis. And the main reason he cared about that was to provide a theoretical framework through which psychic phenomena could operate!

Evil Eye

Sunday, March 7th, 2010

From Lilienfeld et al.’s 50 Great Myths of Popular Psychology (p. 34-5):

As the great Swiss psychologist Jean Piaget noted, this belief [that the eye emits rays or particles that enable it to see objects] begins early in life. Piaget even discussed the case of one child who believed that two people’s looks can connect and “mix” when they meet each other. Consistent with Piaget’s observations, 57% of elementary school children say that something comes out of the eye when people see…. This belief declines from the third to the eighth grade, but it remains widespread….

This “extramission theory” of vision dates back at least as far as Greek philosopher Plato (427–347 B.C.), who spoke of a “fire” that emanated from the eye during vision, which “coalesces with the daylight … and causes the sensation we call seeing”…. Later, Greek mathematician Euclid (circa 3o0 B.C.) described “rays proceeding from the eye” during vision….

Indeed, beliefs about the “evil eye” (mal ojo) inflicting psychological harm on others have long been widespread in many countries, especially Mexico and those in the Mediterranean, Central America, and the Arab world…. Both the Old and New testaments of the Bible refer to the evil eye, and ancient Egyptians applied eye shadow to ward off its sinister influence….

Pressure phosphenes, which we most often see after rubbing our eyes after awakening … may contribute to the belief that the eye emits tiny particles to detect objects. [Also,] the eyes of many animals that possess good night vision contain a “tapetum lucidum,” a reflective layer behind or within the retina. Many of us have seen the gleaming light generated by this layer, sometimes called “eyeshine,” in cats or raccoons at night.

Biblio: Lilienfeld, Scott O., S. J. Lynn, J. Ruscio and B. L. Beyerstein (2010), 50 Great Myths of Popular Psychology: Shattering Widespread Misconceptions about Human Behavior (Chichester, West Sussex: Wiley-Blackwell).

Swami and Mantra

Tuesday, August 4th, 2009

Received my copy of Sam Dalal’s extremely rare and highly anticipated Swami and Mantra by courier today.

The “yogic tricks” in it? Just the old bed-of-nails tricks, the pushing-a-nail-into-your-nostrils-and-nasal-cavity trick, and the biting-a-weakened-nail-in-half trick. Plus the suggestion that the easiest way for Sai Baba to distribute “vibhuti” would be via a fake thumb. Nothing even remotely paranormal or physiological, and therefore a total waste of money, for my purposes.

So that’s $190 I won’t get back … unless I resell it on amazon or something.

Mead and Me

Saturday, July 11th, 2009

Jerry Coyne, in the middle of the Mooney/accommodationist debate:

Science uses logic, reason and evidence to find things out.  Religion uses dogma and revelation.

Well, except that the dogma for them is regarded as properly vetted evidence from reliable sources (to a comparable degree as are refereed journals in science), and religious meditative experiences (as a subset of “revelations”) could in theory be reproducible, as Ken Wilber (of all people!) has rightly noted—even though, in practice, there are no controls in place to ensure that meditators are not merely experiencing what they expect to experience, in “group bias or error.”

Coyne continues:

These are fundamentally different ways of arriving at “truth.” Indeed, religions can’t arrive at truths at all, because the truth claims of different religions are in irresolvable conflict with one another, and there is no way of knowing which of these are wrong and which (if any) are right.

In exoteric terms that’s probably true. But in esoteric readings of holy books (e.g., of the resurrection of the Christ consciousness within you), not only are different religions not in irresolvable conflict with one another, they can actually be read as being in profound agreement in their cartographies of higher states of consciousness—as Paramahansa Yogananda, Wilber, and every advocate of the perennial philosophy have long emphasized.

In contrast, science has built-in ways of determining if it is wrong. When making a truth claim, scientists can answer the question, “How would I know if I were wrong?”  The faithful have no such way to test their “truth” claims.

Again, that’s true only in the literalistic readings of scripture; taking them instead as being based in the internal experience of higher levels of reality, there are indeed (in principle) ways of testing the truth claims (about the existence of auras and of claimed astral travel, etc.). Unfortunately, when those claims get tested by skeptics, they invariably fail. But that’s very different from there being no way of testing whether the claims are wrong.

Of course, the New Atheists are explicitly not directing their arguments toward that kind of “religion.” In fact, I once saw a video of a talk by the philosopher Daniel Dennett where, in the question period at the end, an audience member asked him why he hadn’t covered meditation-based religions like Buddhism in Breaking the Spell. His reasonable response was that he didn’t know enough about them to include them.

Ophelia Benson then commented:

And furthermore—if science can’t test or measure statements about the supernatural, then no one can. I think that formula is very often deployed to suggest (without stating, because of course it isn’t true) that some other ‘way of knowing’ can test or measure statements about the supernatural. But what would those be? Nothing. They would be nothing. There isn’t some other way of knowing that can test or measure things. There’s only one. If the supernatural is out of reach of science then it’s out of reach of human beings and we can’t know anything about it—so we shouldn’t make factual claims about it. We shouldn’t pretend we can know something about it. We shouldn’t suggest that other people can know something about it. It’s a black box—or else it isn’t. It’s not a black box for empiricists but a transparent one for others.

Since (as Wilber—gah—has pointed out) meditation is a “science” (albeit one with woefully inadequate controls), she’s actually (somewhat accidentally) right about the “reach of science” there … unless, of course, the experience of “no space, no time” really is an experience of Spirit (with no actual knowledge content, but still being ontologically real) rather than just a product of one’s parietal lobes and proprioceptive body-sense shutting down. Can science tell us which of those it is? Nope.

So you can see how pathetically little these “New Atheist” arguments can actually do to untangle you from New Age or yogic spirituality, if you’ve gotten yourself involved in those. In fact, it’s perfectly possible and logical for someone like Wilber to be as much of an atheist as Sam Harris, while simultaneously being one of the worst purveyors of post-metaphysical woo-woo on the face of the Earth.

So anyway, all of that got me reading Steven Dutch again, which led me to this:

There are certain classes of miracles that never seem to happen. People have been alleged to be revived from the dead, but no decapitation victim ever has. Nor are there any reliable accounts of severed limbs regenerating.

Which in turn reminded me of one of Yogananda’s stories:

Sadasiva never spoke a word or wore a cloth. One morning the nude yogi unceremoniously entered the tent of a Mohammedan chieftain. His ladies screamed in alarm; the warrior dealt a savage sword thrust at Sadasiva, whose arm was severed. The master departed unconcernedly. Overcome by remorse, the Mohammedan picked up the arm from the floor and followed Sadasiva. The yogi quietly inserted his arm into the bleeding stump.

And that got me thinking about Margaret Mead, and how she swallowed every daffy sex-liberation story told to her by a couple of Samoan girls.

And then it hit me, to a degree which it hadn’t previously: I was as guilty of believing every tall tale Yogananda told, as Mead was of taking those prank-playing girls at their word—of assuming, on good faith, that they wouldn’t outright lie to her. I mean, I knew that I was gullible, but I hadn’t previously realized that I was as gullible as Margaret Mead.

Ouch.

Of course, I wasn’t publishing peer-reviewed papers on all that. But still, there is that first book of mine….

Crystal Balls

Monday, June 15th, 2009

This is why crystals and applied kinesiology don’t work:

And this is why astrology doesn’t work:

And this is why aura-reading doesn’t work:

And this is why psychokinesis doesn’t work:

And this is how cold reading works (with Sue Blackmore at the end!), and then gets presented as if it was
authentic psychic insight:

And this is how “psychic surgery” doesn’t work:

And this is why homeopathy doesn’t work:

And if you want to see what damned fools-in-denial Randi, et al., continually have to deal with, in simply challenging the pretend-”psychics” in the world to put up or shut up:

Hundredth Integral Monkey

Monday, June 15th, 2009

Regarding the supposed Hundredth Monkey Effect beloved of Ken Wilber’s morphogenic friend, Rupert Sheldrake:

Sheldrake has cited the “Hundredth Monkey Effect” as evidence of morphogenetic fields bringing about non-local effects in consciousness and learning.

In 1985, Elaine Myers re-examined the original published research in “The Hundredth Monkey Revisited” in the journal In Context. In her review she found that the original research reports by the Japan Monkey Center in vol. 2, 5 and 6 of the journal Primates differs from [Lyall] Watson’s story in significant ways. In short, it contains no evidence that the “Hundredth Monkey” phenomenon exists; the published articles only describe how the sweet potato washing behavior gradually spread through the monkey troop and became part of the set of learned behaviors of young monkeys. There is no evidence at all of a critical number at which the idea suddenly spread to other islands, and none of the original researchers ever made such a claim.

And further, via a 1985 article in Skeptical Inquirer:

Unsubstantiated claims that there was a sudden and remarkable increase in the proportion of washers in the first population were exaggerations of a much slower, more mundane effect. Rather than all monkeys mysteriously learning the skill it was noted that it was predominantly younger monkeys that learned the skill from the older monkeys through the usual means of imitation; older monkeys who did not know how to wash tended not to learn. As the older monkeys died and younger monkeys were born the proportion of washers naturally increased. The time span between observations were in the order of years.

Claims that it spread suddenly to other isolated populations of monkeys ignore the fact at least one washing monkey swam to another population and spent about four years there. It is also to be noted that the sweet potato was not available to the monkeys prior to human intervention: it is not at all surprising that isolated populations of monkeys started to wash potatoes in the a similar time frame once they were made available.

Michael Shermer explains further, in Why People Believe Weird Things (p. 17-8):

In 1952, primatologists began providing Japanese macaques with sweet potatoes to keep the monkeys from raiding local farms. One monkey did learn to wash dirt off the sweet potatoes in a stream or the ocean, and other monkeys did learn to imitate the behavior. Now let’s examine Watson’s book more carefully. He admits that “one has to gather the rest of the story from personal anecdotes and bits of folklore among primate researchers, because most of them are still not quite sure what happened. So I am forced to improvise the details.” Watson then speculates that “an unspecified number of monkeys on Koshima were washing sweet potatoes in the sea”—hardly the level of precision one expects. He then makes this statement: “Let us say, for argument’s sake, that the number was ninety-nine and that at 11:00 a.m. on a Tuesday, one further convert was added to the fold in the usual way. But the addition of the hundredth monkey apparently carried the number across some sort of threshold, pushing it through a kind of critical mass.” At this point, says Watson, the habit “seems to have jumped natural barriers and to have appeared spontaneously on other islands.

Let’s stop right there. Scientists do not “improvise” details or make wild guesses from “anecdotes” and “bits of folklore.” In fact, some scientists did record exactly what happened…. The research began with a troop of twenty monkeys in 1952, and every monkey on the island was carefully observed. By 1962, the troop had increased to fifty-nine monkeys and exactly thirty-six of the fifty-nine monkeys were washing their sweet potatoes. The “sudden” acquisition of the behavior actually took ten years, and the “hundred monkeys” were actually only thirty-six in 1962. Furthermore, we can speculate endlessly about what the monkeys knew, but the fact remains that not all of the monkeys in the troop were exhibiting the washing behavior. The thirty-six monkeys were not a critical mass even at home. And while there are some reports of similar behavior on other islands, the observations were made between 1953 and 1967. It was not sudden, nor was it necessarily connected to Koshima. The monkeys on other islands could have discovered this simple skill themselves, for example, or inhabitants on other islands might have taught them. In any case, not only is there no evidence to support this extraordinary claim, there is not even a real phenomenon to explain.

OBEs and NDEs

Monday, June 15th, 2009

The best explanation of near-death experiences (NDEs) I’ve found? Woerlee’s Darkness, Tunnels, and Light.

Darkness, tunnel, and light experiences are wondrous, seemingly paranormal experiences. Nonetheless, it is evident that they can be explained by the body’s responses to oxygen starvation. The combination of tunnel and light experiences can only be explained by oxygen starvation, and nothing else. Other associated experiences, such as darkness and out-of-body experiences, can also be generated by other changes in body function induced by a wide range of different conditions.

Correspondingly, from Matthew Alper’s The “God” Part of the Brain:

[I]n the majority of recorded accounts, the first thing most people recall of their experience is a feeling of intense fear and pain that is abruptly replaced by a sense of calm, serenity and bliss. To offer support of a neurophysical model of this phenomenon, D. B. Carr suggested that the aforementioned sensations, in so far as they are experienced during an NDE, might come as the result of a flood release of endogenous opiods (endorphins).

After experiencing this sense of calm or euphoria, the next most often related symptom to occur during an NDE is that of an “out-of-body” experience (OBE). Here, the person describes a sensation of having risen outside of their physical body and, in many cases, even being able to look down at one’s own self from above. [Footnote: One hospital, in order to validate claims of "out-of-body" experiences, placed an LED marquee above its patients' beds which displayed a hidden message that could only be read if one were looking down from above. To date, not one person who has claimed to have had an NDE or OBE within that hospital has expressed having seen the hidden message.] (p. 151)

Given that NDEs occur, as the name suggests, when our lives are at stake, it would make sense that the body would release chemicals that induce a state of calm and serenity. For instance, if we are in the process of bleeding to death, the worst thing we can do is to panic which will only increase our heart rates, which would only expedite the rate of blood loss. Rather, it’s to our advantage that the body should induce a state of calm and euphoria that will slow our heart rates, thus decreasing the rate of blood loss. This is most likely the adaptive function of an NDE, to calm us in the midst of life-threatening events so as to bolster our chances of survival. (p. 153)

The Nobel Prize-winning physicist Richard Feynman, as you may know, had some fun inducing his own out-of-the-body experiences back in the ’70s. From his “Surely You’re Joking, Mr. Feynman!” (p. 333-4):

I had hallucinations almost every time [in the sensory-deprivation tank], and was able to move further and further outside of my body…. “I” even got out of the room, ultimately, and wandered about, going some distance to locations where things happened that I had seen earlier another day.

I had many types of out-of-body experiences. One time, for example, I could “see” the back of my head, with my hands resting against it. When I moved my fingers, I saw them move, but between the fingers and the thumb I saw the blue sky.

Pendulums

Monday, June 15th, 2009

From Barbara Ann Brennan’s Hands Of Light (p. 81-2):

The best way I have found to start sensing the states of the chakras is to use a pendulum….

To measure the state of the chakra, hold the pendulum on a string about six inches long over the chakra [as the patient lies on his back or stomach] and empty your mind of all bias as to the state of the chakra. (This is the hardest part and requires practice.) Be sure that the pendulum is as close to the body as possible without touching it. Your energy flows into the field of the pendulum to energize it. This combined field of the pendulum and your energy then interacts with the field of the subject, causing the pendulum to move…. It will probably move in a circular pattern, circumscribing an imaginary circle above the body of your subject. It may move back and forth in an elliptical movement or a straight line. It may move erratically. The size and direction of the pendulum movement indicates the amount and direction of energy flowing through the chakra.

Likewise, from Rosalyn Bruyere’s Wheels Of Light (p. 73-5):

When used as a pendulum, a prism or crystal is a tool that can corroborate chakra movement. This is because a crystal is an effective energy transmitter. (It is able to rectify the moving electromagnetic field of the chakra into a direct current.) When a crystal is suspended over the chakra of a reclining person, the energy of the spinning chakra will cause the crystal to swing in a corresponding motion.

As James Randi explains, however:

One method of divination uses a pendulum. A weight of any kind, the bob, is suspended at the end of a string or chain: crystals, real or fake, are currently popular. The device is held over a map or other object, and various movements of the bob are interpreted in different ways by different operators….

In this phenomenon, it can always be seen that the subject moves his or her hand to set the pendulum swinging, though this will be vehemently denied. The event is a perfect example of ideomotor reaction.

Ah yes, our old friend from the world of dowsing, the ideomotor effect:

The movement of pointers on Ouija boards, of a facilitator’s hands in facilitated communication, of hands and arms in applied kinesiology, and of some behaviors attributed to hypnotic suggestion, are due to ideomotor action. Ray Hyman … has demonstrated the seductive influence of ideomotor action on medical quackery, where it has produced such appliances as the “Toftness Radiation Detector” (used by chiropractors) and “black boxes” used in medical radiesthesia and radionics (popular with naturopaths to harness “energy” used in diagnosis and healing.)

Yes, Brennan endorses the ineffectual nonsense of radionics, too. “Surprise.”

Miracle of Palming

Monday, June 15th, 2009

From Ram Dass’s (1979) Miracle Of Love: Stories About Neem Karoli Baba (p. 129-30):

Once in Vrindaban before Guru Purnima Day (a day honoring the guru), Maharajji was feeding us by hand. One by one he would feed us each a pera. I tried to feed him one, too. Of course he didn’t eat sugar, but I was insisting, with the thought that this was also prasad. “You must eat it, please eat it.” So he pretended to eat it.

But Naima caught him: “You didn’t eat it, Maharajji.” He looked guilty, as if to say, “Oh, you caught me.” There it was in his hand. He’d palmed it. That precipitated wonderful play, as he went into his whole magician act:

“Which hand is it in? Ha! You’re wrong, it’s in this hand.” I don’t think he was even using his powers for this game. He really was palming it, hiding it in his blanket, and using sleight of hand—all tricks that any magician can do. But he was saying, “See! See! I’m like Sai Baba. I can make it appear; I can make it disappear. I can do anything. Magic! It’s magic!”

Neem Karoli Baba (a.k.a. Maharajji) was, of course, the same guru-figure who supposedly ingested 900+ micrograms of LSD, given to him by Ram Dass, with no ill effect. In fact, the story is told in the very same book (and elsewhere), on pages 229-30:

The whole thing happened very fast and unexpectedly. When I returned to the United States in 1968 I told many people about this acid feat. But there had remained in me a gnawing doubt that perhaps he had been putting me on and had thrown the pills over his should or palmed them, because I hadn’t actually seen them go into his mouth.

Three years later, when I was back in India, he asked me one day, “Did you give me medicine when you were in India last time?”

“Yes.”

“Did I take it?” he asked. (Ah, there was my doubt made manifest!)

“I think you did.”

“What happened?”

“Nothing.”

“Oh! Jao!” and he sent me off for the evening.

The next morning I was called over to the porch in front of his room, where he sat in the mornings on a tucket. He asked, “Have you got any more of that medicine?”

It just so happened that I was still carrying a small supply of LSD for “just-in-case,” and this was obviously it. “Yes.”

“Get it,” he said. So I did. In the bottle were five pills of three hundred micrograms each. One of the pills was broken. I placed them on my palm and held them out to him. He took the four unbroken pills. Then, one by one, very obviously and very deliberately, he placed each one in his mouth and swallowed it—another unspoken thought of mine now answered.

As soon as he had swallowed the last one, he asked, “Can I take water?”

“Yes.”

“Hot or cold?”

“It doesn’t matter.”

He started yelling for water and drank a cup when it was brought.

Then he asked, “How long will it take to act?”

“Anywhere from twenty minutes to an hour.”

He called for an older man, a long-time devotee who had a watch, and Maharajji held the man’s wrist, often pulling it up to him to peer at the watch. Then he asked, “Will it make me crazy?”

That seemed so bizarre to me that I could only go along with what seemed to be a gag.

So I said, “Probably.”

And then we waited. After some time he pulled the blanket over his face, and when he came out after a moment his eyes were rolling and his mouth was ajar and he looked totally mad. I got upset. What was happening? Had I misjudged his powers? After all, he was an old man (though how old I had no idea), and I had let him take twelve hundred micrograms. Maybe last time he had thrown them away and then he read my mind and was trying to prove to me that he could do it, not realizing how strong the “medicine” really was. Guilt and anxiety poured through me. But when I looked at him against he was perfectly normal and looking at the watch.

At the end of an hour it was obvious that nothing had happened. His reactions had been a total put-on. And then he asked, “Have you got anything stronger?” I didn’t. Then he said, “These medicines were used in Kulu Valley long ago. But yogis have lost that knowledge. They were used with fasting. Nobody knows now. To take them with no effect, your mind must be firmly fixed on God. Others would be afraid to take. Many saints would not take this.” And he left it at that.

So what do you think? Given that NKB knew sleight-of-hand magic well enough to fool his disciples, in palming sweets, does Dass’s always-credulous reporting of Maharajji swallowing the LSD deserve to be taken seriously?

No, it does not.

“He took the four unbroken pills.” But not the broken one. Why? Because he wouldn’t have been able to switch that broken one with the dummy pills he was already concealing. (He knew what they should look like from the previous time in 1968, when he had indeed palmed them.)

Note that NKB didn’t take the unbroken pills, one by one, out of Ram Dass’s hand. Rather, by Dass’s own testimony, Baba took all four unbroken pills from Dass—surely into his (NKB’s) own, empty hand—before swallowing any of them.

Even without being a close-up magician yourself, you can figure it out from there: Baba casually discarded those real LSD pills/tablets into his blanket or elsewhere, transferred the dummies from his other hand into the one that had formerly held the drug while misdirecting Dass’s attention, and then “very obviously and deliberately … placed each [of the dummy pills] in his mouth and swallowed it.” Or something very like that.

“He started yelling for water.” More misdirection, probably to allow him to properly dispose of the original pills.

If NKB had really wanted to put Dass’s doubts to rest by actually swallowing the LSD in 1971, he would have had Dass put the pills into his (Baba’s) mouth himself, one by one, with a thorough mouth-check afterwards. That’s how it’s done in clinical drug studies, so that you can’t get away with palming the drug, or hiding it under your tongue or along your gumline, etc. (They wouldn’t have those safeguards in place in the clinical-testing world if people hadn’t tried all of those tricks in the past.)

Or at the very least Baba would have taken the real LSD pills, one by one, out of Dass’s hand, and put them directly, one by one, into his own mouth, letting Dass’s eyes follow each pill all the way, chewing or swallowing them, and then opening his mouth for a thorough inspection. (In Grist for the Mill [p. 89], Dass says that Maharajji “took each tablet and stuck it in his mouth and made sure that I saw, and he munched them up.” But, of course, there’s “many a slip ‘twixt cup and lip,” when it comes to the steps between Dass’s hand and Neem Karoli Baba’s mouth.)

As usual, Ram Dass got utterly snowed by a simple trick, and he still hasn’t figured it out, even three and half decades later.

Some people just never learn. If the world ever needs a patron saint for the idea that the road to hell is paved with good intentions, no one could play that role better than Dass himself: Few people have done more harm, with better (and unendingly credulous) intentions, than Ram Dass.

In the beginning you may not see any light just an empty darkness or a somewhat hazy glow. Keep looking intently, be still, calm but fully concentrated. As and when you see any speck of tight or some colored glow, concentrate gaze steadily. Many colored lights of different shapes and intensities will appear from time to time. Do not waste time in trying to analyze them. Just know that the astral body is made of such colored lights. Regular practice of Jyoti mudra and steady gazing at the eyebrow center will reveal a golden circular light with a blue circle inside it. This is the light of the spiritual eye. Inside the blue circle advanced Yogis see a five pointed white star. This star is the focal point of advance concentration and meditation. Yogis penetrate their consciousness through this star and experience the infinite kingdom of God beyond and its bliss. (Mind: Its Nature)

Using your thumbs, index fingers, middle, ring, and little fingers to close your ears, eyelids, nostrils, and upper and lower lips, take in a slow full breath and hold, pressing very gently against the eyelids on the lower edge of the bony socket (not on the cornea) to release eye tension in a flourish of colors and patterns. Watch them in meditative wonder. This completes the yoni mudra. (Stuart Sovatsky, Eros, Consciousness, and Kundalini, p. 108)

However, we learn from Margaret Singer’s Cults In Our Midst (p. 136):

Former members report that in [Maharajji's] Divine Light Mission the lights would be dimmed and the guru would pass among the followers bestowing “divine light” on individuals by pressing on their eyes until the pressure on the optic nerve caused them to see flashes of light. This was reframed as Divine Light.

The same (self-induced) thing was happening in Yogananda’s SRF, of course, with physical phenomena and mere overactive imagination being framed as if they were “spiritual experience.” And if you don’t think that overly active imaginations are capable of generating inner phenomena such as the “spiritual eye,” think again:

[T]he core issue for Jim was his belief that he had “spiritual” experiences, such as seeing a golden light emanating from [Frederick] Lenz and filling the room. I explained that hallucinations like these are often the result of easily reproducible hypnotic processes that have very little to do with being spiritual. Jim said, “Prove it.” So I was forced to demonstrate this hypnotic effect for him. I asked him to close his eyes and meditate, as he had been doing for months as a student of Lenz. Once I saw his facial muscles relax, I added, “You’re going to meditate even deeper than you have ever done before, and I don’t want you to open your eyes until you’re ready to see an even brighter light emanating from me.” We waited less than a minute, and when he opened his eyes, he looked at me and said, “Whoa! That’s brighter than the light I saw coming from Lenz!” (Steven Hassan, Releasing the Bonds, p. 63-4)

By the same token, consider David Lane’s demonstration of the Kirpal Statistic:

Of the some 80,000 people Kirpal Singh initiated from 1948 to 1974, a majority of them claimed to have had some type of inner experience, ranging from simple visions of blue, green, and red lights to hearing subtle sounds like a bell, conch or a flute to sophisticated encounters with radiant yogis, sages, and mystics….

I tried several meditation experiments with my students which convinced me that Kirpal Singh and other gurus like him were taking undue credit for their disciples’ inner experiences. In my trial meditation sessions, I informed my students beforehand about the possibility of seeing inner lights and hearing inner sounds…. I informed them that I knew of an ancient yoga technique that would facilitate their inner voyages. I turned the lights off, instructed them briefly about closing their eyes gently and looking for sparks of light at the proverbial third eye. I told them that I would touch some students on the forehead lightly with my fingers. They meditated for some five minutes. I then proceeded to ask them about their experiences…. To my amazement, since I felt that Kirpal Singh and others were actually transmitting spiritual power, the majority of my students reported seeing light. A few students even claimed to have visions of personages in the middle of the light. Others reported hearing subtle sounds and the like.

All of which, however, still pales in comparison with the hallucinatory experiences of Ram Dass’ buddy, Bhagavan Das, as related in his It’s Here Now (Are You?) (p. 127, 136):

As the Karmapa sat reading aloud from a Tibetan text, he kept looking at me. I felt as if my body had turned into a giant pot and he was pouring a substance into me. He was filling me with the sounds that were coming from his mouth. These were sacred teachings spoken in a language I couldn’t understand. These sounds were turning into deities: hundreds and hundreds of tiny vajra dakinis falling into me from the sky like snowflakes. They each had a little skull cup and a khatvanga (a trident with a skull on top of it). Each had three eyes, and they were naked and had beautiful breasts. Light emanated from their yonis (vaginas)….

Many times I’d be walking around the temple and I would actually see dakinis flying around its pinnacle. I was amazed to see these fairy beings, these miniature goddesses.

Pressing on your eyeballs, in the jyoti mudra taught by Yogananda and others, makes pretty lights appear. It also invokes the oculocardiac reflex, which slows down one’s heart, sometimes even to the point of asystole and death.

And when you’ve found something that both causes “inner lights” to appear, and measurably slows the beating of your heart, you know you’ve found the “airplane route to God.”

Never mind that both effects are purely physiological and non-paranormal.