When God Talks Back: Understanding the American Evangelical Relationship with God, Luhrmann 2012; ch 7:

"Many years ago, as a young ethnographer, I had studied people who practiced magic in present-day Britain as my dissertation project. I was curious about how magic could come to seem real to modern people. Most of these people thought of themselves as worshipping an ancient goddess under the full and pendulous moon. For them the earth was alive, and they sought to feel its power pulsing beneath their feet. They described themselves as shamans, druids, witches, and warlocks, responsive to the subtle rhythms of the earth. They lived in London, these magicians, and they held modern jobs and had modern lives, but they imagined themselves into another time. When I set out to understand how they came to believe in magic, I did what anthropologists do: I participated in their world. I joined their groups. I read their books and novels. I practiced their techniques and performed in their rituals. For the most part, I found, the rituals depended on techniques of the imagination. You shut your eyes and saw with your mind's eye the story told by the leader of the group. The techniques were pretty close to Christian kataphatic prayer practice. Some magicians even referred to these techniques as "Ignatian."...What startled me, as a young ethnographer, was that this training worked. At least, it seemed to shift something in the way I used my senses and my internal sensory awareness. After about a year of this kind of training, spending thirty minutes a day in an inner world structured in part by external instructions, my mental imagery did seem to become clearer. I thought that my images had sharper borders, greater solidity, and more endurance. They had more detail. I felt that my senses were more alive, more alert. My concentration states seemed deeper and more sharply different from the everyday. One evening I was reading a book about Arthurian Britain and the early Celtic isles (it was written by a magician), I allowed myself to get deeply involved with the story, reading not the way I read a textbook but the way I read books like The Secret Garden as a child, giving way to the story and allowing it to grip my feelings and to fill my mind. I read late into the night. And as I woke the next morning, I saw six druids standing against the window, above the stirring London street below. I saw them, and they beckoned to me. I stared for a moment of stunned astonishment, and then I shot up out of bed, and they were gone. Had they been there in the flesh? I thought not. But my memory of the experience is very clear...other people in the magical world had experiences like that. They practiced the exercises and read the books and participated in the rituals, and then, out of the blue, they saw something-the Goddess, or a flash of divine light, or a shining vision of another world. They saw these as things in the world, not phantoms in the mind, although because the image vanished almost immediately, they knew that what they had seen was not ordinary. I had wondered for many years if something about the practice associated with magic made these supernatural experiences more common. When I encountered the same spiritual techniques in experiential evangelical Christianity, I was determined to find out.

My father, a clinician, had introduced me to this scale back when we were talking about the pathological and nonpathological shifts in the ways people experience and perceive, and I threw it in with the others in the packet because I liked the questions it asked. The questions seemed to tap someone's willingness to be caught up in their imaginative experience, and in nature and music, and I had a hunch that what the questions captured was connected to the experience of God.
This was the Tellegen Absorption Scale. It has thirty-four statements that one marks as true or false, meaning true or false for the person filling out the scale. A subject gets a point for every "true." The scale does not measure religiosity per se; it has only one statement that could be construed as religious. Instead, its statements describe experiences of nature and color and music. They describe textures and smells. There are statements that assert that you, the scale-taker, sometimes experience things as a child; that you can "see" the image of something when no longer looking at it; that you sometimes discover that you have finished a task when your thoughts are elsewhere; that different smells call up different colors; that you often sense the presence of a person before seeing him or her; that you can become oblivious to everything else when listening to music; that you sometimes keep listening to a fascinating voice.6
I gave the absorption scale to all the people in the Chicago church I interviewed systematically, and then I compared their answers to the answers they gave to the questions I asked about their spiritual experience (the senses cluster, the focus cluster, and the personlike cluster). It turned out that they were closely related. A person's absorption score was not related to the length of time he or she prayed on a daily basis. That is, the scale did not measure prayer practice per se. But the way a person answered the absorption questions was significantly related to the way he or she experienced prayer. The more absorption statements people marked as true, the more focus cluster experiences they reported (for example, that time seemed to change when they prayed, or that they went to a different place in their mind). The more absorption statements they endorsed, the more they said they experienced God with their senses (for example, that they commonly got images and sensations in prayer, or that they had felt God touch them). Most remarkably, the way someone answered the absorption scale predicted whether he or she was able to experience God as a person. You might think that my questions ("Do you speak to God freely throughout the day?" "Would you describe God as your best friend or as like an imaginary friend, except real?" and so forth) would lead people just to parrot back what the pastor and the books and the conferences say about God so often. But those who had high absorption scores were much more likely to report that they experienced God as if God really was a person-someone they could talk to easily, who talked back, with whom they could laugh, and at whom they could get angry. People with low absorption scores said that they couldn't. When I held the absorption score constant, the time spent in prayer turned out to be significantly related to how personlike God was for someone.7 It appeared that there really was something like talent, and something like training, and that both mattered to the way someone experienced God.
...The people who did not experience God in the vivid way the church thought they should also did not think that the absorption scale described them. Jacob, who had wanted and expected a mountaintop experience but didn't have one, marked "true" for only four of the items. Fred, who glumly said he hadn't had these powerful experiences (and who later asked our house group to pray for him so that he would hear God speak "with a booming voice"), marked "true" for only five. He even wrote next to one item, "There are such people?" Alice, who said she'd be afraid of prophecy, marked "true" next to only thirteen. When I eventually gave the scale to Sarah, so often held up as an example of a prayer warrior, she marked "true" for thirty-three of the thirty-four items. When she finished writing on the questionnaire that afternoon in my office, she looked up with a smile and said, "The man who created this scale lived inside my head."
There was another interesting thing the absorption scale predicted. If people answered "true" to at least half the items on the absorption scale, their chances of reporting that they had heard God's voice or felt God's touch or seen the wing of an angel or had a sensory perception of something supernatural (like hearing God say "I will always be with you" from the backseat of a car) was six times as high as for those who said "true" to less than half the statements. It turned out that slightly over a third of the subjects reported sensory experiences of something not materially present.

Some psychologists find that high-absorption women are, in the eyes of observing clinicians, aesthetically focused and interesting; that they use unconventional thought processes; that they are imaginative, socially skilled, expressive, and introspective. High-absorption men are warm, giving, aesthetically oriented, nurturing, likable, and interesting.15
The clinical literature tells a darker story. Women who report recovered memories of sexual abuse score more highly on the absorption scale than those who report either continuous memories of abuse or no abuse. So do people who remember being abducted by aliens.16 This suggests that people who are high absorption may become confused about the difference between fantasy and fact.

The kataphatic group did better, on average, on objective measures of mental imagery use. At least their mean scores were slightly better, and a higher percentage of those who were really successful came from the kataphatic group. Subjects in the kataphatic group were more able to solve the shapes puzzle and the paired words puzzle, and they picked up more of the target letters that flashed by so quickly that they were almost a blur. When congregants said that people who became prayer experts would develop sharper imagery, on average, they were right. The phrase on average is important. Not everyone who did the kataphatic exercises reported that their imagery grew more vivid. But on average, when you looked across the group, if someone had spent thirty minutes a day, more or less consistently for a month, engaging with Christ in their minds through these kataphatic prayer tracks, whether they liked them or not, their mental imagery did become more vivid. And when we faded the shapes and phrases out to grayscale and noise, the kataphatic group reported that they heard them for longer, and saw them for longer, than the study group.31

Another study in northern California looked at already-trained apophatic meditators who agreed to retreat to a Zen monastery for three months of full-time meditation. After meditating for at least five hours a day for twelve weeks, the subjects were able to distinguish visually between two slightly unequal lines that they had seen as identical before. They were literally able to see more because they were able to pay attention more closely.33
Most Christians, of course, do not pray in this focused way for five hours each day outside the monastery. (They have day jobs.) They are supposed to pray for thirty minutes, and they do not always do that. That we were able to get results with only thirty minutes of daily practice, more or less, suggests that when Christians pray in the ordinary, regular way that their pastors and prayer manuals recommend, something changes in the way they use and experience their minds' capacities.
And again, proclivity for absorption seems to make a difference. The more items someone endorsed on the absorption scale, the higher their initial score on the two subjective mental imagery items. But being high-absorption did not help one to solve the shapes puzzle and the paired words puzzle. If anything, in fact, being high-absorption interfered. Some of the logical puzzles that demanded mental imagery use were done significantly less well by those who scored highly on the absorption scale.

The second finding about sensory overrides was that both absorption and training make a difference. In the initial interview, people who were higher in absorption were more likely to say that they had heard a voice when alone, and the more absorption statements they endorsed, the more hearing-voices stories they said had happened to them. Meanwhile, those who had the kataphatic discipline reported more sensory overrides on return than those with the study discipline.35 The overrides were not, in general, very dramatic, and there weren't many of them, but some were meaningful and moving. One subject, for example, had a powerful experience of God holding her hand. Another woman saw her beloved dead dog. Another had a session in which she closed her eyes to visualize the angel Gabriel and found that the angel's light was so bright that she opened her eyes because she thought someone had turned a lamp on in the room.

Most liked some of the tracks more than others. The 23rd Psalm track went over the best, but not with everyone. "The word that immediately comes to mind is annoying," one person commented. Some objected to the homemade scratchiness of the voice-over and the fact that they could hear when I had turned on the microphone. A couple were simply polite: "I did enjoy it, to a certain extent." But no one who stayed with the project hated the kataphatic discipline, and most listeners really liked it. "I was close to God before, but I feel very close now. I feel like he's inside me." Or "I wanted to feel the peace and it really works." The woman who said that listened to the tracks more than two hundred times. She said it cured her acne.

For those who liked it, the pink noise on the iPod seemed to become textured with meaning. Subject 110 came to the discipline during a hard month. Both of her parents were dying, and she had to take charge of the family business while she cared for them. She was fifty. She had been raised Episcopalian, but she no longer went to church. Still, she prayed every day. She had done centering prayer before, and she found that it became a kind of oasis during her day. She said that it was like plugging herself into a battery. She talked about calm and peace, but the pink noise also seemed to dissolve into meaning. One day she heard trumpet notes and the crying of birds. She saw pulsating light against her eyelids. She heard messages: "Cultivate what you have," which made sense to her, and "Excuse me," which she never understood.

The experimenter reads some words aloud and puts up pictures of other words and asks subjects to remember which words they saw and which they heard. A trickier version (once a psychology colleague of mine remarked that his was the only academic discipline that legally tortures its subjects) involves reading out a series of words (sour, candy, sugar, bitter, good, taste) and then reading out a new list into which are added words naturally associated with the first list but not actually on it, like sweet. Many people mistakenly conclude that sweet was on the first list, because it just makes so much sense that it would be. On these kinds of tasks, people who score highly on questionnaires that ask them whether they've had hallucination-like experiences are also more likely to make mistakes on source monitoring tasks.43
From the reality monitoring perspective, hallucination-like experiences occur not because there's something wrong with your mind, but because you interpret something you imagined as being real in the world. The issue is perceptual bias, not perceptual deficit. The psychologist Richard Bentall, who is the primary intellectual architect of this interpretation, suggests that the most common conditions that lead to hallucinations-what we might call the ingredients of a supernatural experience-are an ambiguous stimulus, emotional arousal, and cognitive expectation. Someone who perceives an ambiguous noise is more likely to interpret it; someone who needs an answer is more likely to listen for one; and someone who believes that an answer can be heard is more likely to hear one...One study in London found that one in ten whites reported a voice or vision; one in twenty South Asians; and one in four sub-Saharan Africans or African Caribbeans. The slight data we have on hallucinations associated with psychiatric illness outside the West suggests that both the sensory mode and the content shift across cultural boundaries.

This account of absorption training is fully compatible with both secular and supernaturalist understandings of God. To a believer, this account of absorption speaks to the problem of why, if God is always speaking, not everyone can hear, and it suggests what the church might do to help those who struggle. To a skeptic, it explains why the believer heard a thought in the mind as if it were external.

Happold's experience changed his life. But he also includes in his anthology this fey reminiscence by a man who had what seems to be much the same psychobiological explosion and yet that led nowhere:
    The thing happened one summer afternoon, on the school cricket field, while I was sitting on the grass, waiting my turn to bat. I was thinking about nothing in particular, merely enjoying the pleasures of midsummer idleness. Suddenly, and without warning, something invisible seemed to be drawn across the sky, transforming the world around me into a kind of tent of concentrated and enhanced significance. What had been an outside became an inside. The objective was somehow transformed into a completely subjective fact, which was experienced as "mine," but on a level where the world had no meaning; for "I" was no longer the familiar ego. Nothing more can be said about the experience, it brought no accession of knowledge about anything except, very obscurely, the knower and his sense of knowing. After a few minutes there was a "return to normalcy." The event made a deep impression on me at the time; but because it did not fit into any of the thought patterns-religious, philosophical, scientific-with which, as a boy of fifteen, I was familiar, it came to seem more and more anomalous, more and more irrelevant to "real life," and was finally forgotten.50
Even an exalted mystical state, without a framework to interpret it as spiritual, simply registers and slowly fades."