In the beginning...
Of the Quantum Leap in Neurotheology
Interview with Dr. Fred Previc
Fred Previc's new bookEvery now and then, a theory comes along that alters our perspective of the world to such an extent that it forces major philosophical change. Great theories simplify the world, with the mass of confusing and contradictory data from which they were born falling quickly into place. One such theory was the heliocentric theory of Copernicus, which eliminated the complicated and arbitrary introduction of epicycles and deferents to make the geocentric theory of Ptolemy work. Another such theory was evolution, which organized earth's immense biodiversity and fossil evidence into a system of natural selection of inherited traits.
Both theories not only improved the human understanding of the world, they reduced the central role of humans in that world. The expansion of knowledge of the universe has put humans into a progressively smaller position, and given a progressively diminished role to religion in organizing social behavior. While the Copernican theory was quickly approved by the Catholic Church, the religious debate over Darwin's theories rages to this day.
Darwin's scientific intuitions were uncanny, and he not only proposed that the human propensity for religious beliefs were a sort of an innate tribal survival strategy, he further suggested that the human brain was wired for religion: “love of deity [is an] effect of [the brain’s] organization". Given this head start, the scientific community was remarkably lackluster in following Darwin's lead.
The relationship between religious episodes and epilepsy had been documented by the ancient Greeks, but besides a handful of studies, not much can be noted until The varieties of religious experience in 1902 by William James. James outlined a relationship between psychopathology and religious experience, conversion, and the founders of new religious movements. Contrary to Darwin's intuitions, James rejected any evolutionary value of religion (i.e., the "survival-theory"), and rather, viewed religion as a rational attempt at understanding the universe.
While James inferred a psychopathology to the extrema of religious behavior, Sigmund Freud attacked mainstream religious beliefs, curtly proposing that "religion is like a collective neurosis". This was highly controversial, as there was no convincing evidence that "normal" levels of religiosity were associated with mental disorders. Freud's theatrics aside, in The Future of an Illusion (1927), he indeed proposed a very practical purpose for religion, following the theme of repression of antisocial behaviors.
William JamesWhile the 19th century punctuated a sporadic rekindling of interest in mental disorders and religious experiences, it wasn't until the latter part of the 20th century that a few bold scientists would seek neurological explanations of religious beliefs. These were often apologetic efforts, and carefully worded so as not to step on the toes of the religious, which represented most of the population.
And once again, epilepsy was the centerpiece. A preponderance of studies have drawn correlations between religiosity with one or more of the various phases of epilepsy. But in particular, it was temporal lobe epilepsy (TLE) that was a primary suspect in sudden religious conversions (Dewhurst, 1970) and hyperreligiosity (Waxman, 1975). It is also interesting, in light of Previc's theory, that damage to the left inferior temporal lobe can produce upper visual field neglect.
In 1980, Arnold Mandell would champion a sort of "religious serotonergic inhibition model" of temporal lobe function, of which neurological states of transcendent consciousness were facilitated via
drugs that reduced serotonin synthesis and release. Michael Persinger (1983) would subsequently become the most prominent proponent of the temporal lobe's role in religiosity, stating "the God Experience is an artifact of transient changes in the temporal lobe" and "occur as small micro-seizures within the temporal lobe".
Michael Persinger Persinger's religious theories were comprehensive, and sought to explain a wide variety of phenomena: positive and negative religious experiences; hallucinations and paranormal experiences; concepts of God (which he associated with the left hemisphere); and, evolutionary aspects of religious belief.
However, TLE wasn't the only mental disorder with a religious twist, as OCD, mania, and schizophrenia had a growing inventory of studies regarding elevations in religious activity. Schizophrenics reported high frequencies of religious delusions, from 70% in the Kroll study (1989), to 63% in the Rudalevièiene study (2008). The temporal lobe was not the only game in town when it came to religiosity, with the frontal (particularly on the left side) and parietal regions also being implicated in a variety of religious experiences.
This brings us to the work of Eugene D'Aquili and Andrew Newberg, which was narrow in focus, only dealing with subsets of the spiritual that were highly experienced in meditation and prayer. However, the results were particularly fateful for the evolution of Previc's theories, as they elucidated how the feeling of "oneness" with "God/Universe" was related to the neural correlates of the brain's construction of the "self" and the "rest of the world", which was also echoed in the work of Persinger.
The sophisticated practitioners of meditation and prayer were manipulating the activity of various brain systems involved in the orientation of the body in space. The ingenious D'Aquili-Newberg model was a big boost for the fledgling science of neurotheology, but the immense diversity of religious phenomena was still a confusing maze of seemingly unrelated facts: the high rates of psychopathology (particularly with the dopamine system) associated with religious conversions, dreams, hallucinations, and awakenings; the organization of God and heaven into upper, distant space (and the Devil in lower space); the heavy role of incentive-motivational behavior associated with religious activity; and, the interesting correlations between religious thought and general abstract reasoning.
Andrew Newberg and Eugene D'Aquili In 1993, at the time of the publication of the D'Aquili-Newberg paper, Religious and Mystical States: A Neuropsychological Model, Dr. Fred Previc was working as an experimental psychologist for the United States Air Force's School of Aerospace Medicine. Previc spent several years as the lead of the Spatial Disorientation Countermeasures Task Group, where he studied pilot disorientation in flight, a leading cause in aeronautic accidents.
Previc's research would lead to a paper, The Neuropsychology of 3-Dimensional Space (1998), proposing an ingenious model of how humans orient themselves in 3-dimensional space. The long history of visual experiments and lesion analyses led to a breakdown in the idea that humans construct a single version of space, rather, they construct multiple versions to optimize the simultaneous execution of various categories of behaviors. Previc's model of space consists
of four realms: peripersonal (near-body space); focal extrapersonal (visual search and object recognition); action extrapersonal (topographic space); and, ambient extrapersonal (fixed-earth space).
Each of these four spatial realms were managed by a distinct cortical network, which, as Previc quickly realized, overlapped the cortical networks identified by D'Aquili and Newberg that were activated in meditative-prayer states. But, there was much more theology for the taking in Previc's four-realm model of 3-dimensional space. The ventral dopaminergic pathways, which formed the backbone of Previc's action extrapersonal space, and were biased towards the upper visual field, were closely linked to religious behavior.
Fred Previc Everything fell into place with Previc's theory: the higher rates of religious behavior associated with the various dopaminergic mental disorders and the positioning of the good gods and heaven into upper, distant space (and the positioning of the Devil into lower space); the dopaminergic and extrapersonal nature of religious dreams and hallucinations; the orientation of the religious to seeking rewards in distant space and time (i.e., heaven); the close correlation between religiosity and political conservatism; and the preoccupation of the rapidly evolving human version of intelligence with religion.
In 2006, Dr. Previc published The role of extrapersonal brain systems in religious activity, outlining what was indeed the Copernican moment of neurotheology, and one of the great insights in the history of neuropsychology.
Dr. Previc has graciously consented to an interview with us, and it would be advisable to read The role of extrapersonal brain systems in religious activity to make sense of the following discussion. I have provided a brief synopsis of Previc's theory, God, Dopamine, and 3-Dimensional Space, which further relates political disposition to Previc's theories.
The many theories of Fred Previc
(1991) A general theory concerning the prenatal origins of cerebral lateralization in humans. Psychological Review
(1998) The neuropsychology of 3-D space. Psychological Bulletin. Psychological Bulletin
(1999) Dopamine and the origins of human intelligence. Brain and Cognition
(2006) The role of extrapersonal brain systems in religious activity. Consciousness and Cognition
(2007) Prenatal influences on brain dopamine and their relevance to the rising incidence of autism. Medical
Hypothesis(2009) The Dopaminergic Mind in Human Evolution and History. Cambridge University Press
Interview with Dr. Fred Previc
Brack: Fred, before we talk about God, politics, and the evolution and future of the human species, I’d like to first talk about your “4-realm” model of 3-dimensional space as you have outlined in your paper, The Neuropsychology of 3-D Space. Do people tend to favor “living” in peripersonal and ambient extrapersonal space (right hemisphere) at the expense of action and focal extrapersonal space (left hemisphere), and vice versa? Hemispheric dominance seems to hint that this might be the case.
Previc: We all move between activities in peripersonal vs. extrapersonal space … for example, when we plan a future endeavor we are focusing more on extrapersonal space and distant time, whereas when we are eating or dressing or engaged in other manual activities we are operating more within the peripersonal realm. Some individuals, however, focus more on distant space and time (folks who are very achievement oriented, who are conceptually oriented, etc.) whereas others focus more on more immediate space and time. In general, the left hemisphere, and especially its ventral portion, is more concerned with distant space and time whereas the earthier right hemisphere is much more attuned to our body and the emotional systems related to physiological arousal mechanisms in our body. So, individuals who exhibit more of a left-hemispheric style are less likely to be concerned with their body functions and more with more distant, future events. For example, Albert Einstein and Isaac Newton were both known to neglect their own appearance and even go without meals when deep in thought!
Brack: One of the fundamental ideas of Zen Buddhism is "living in the moment", whereas the western religions, such as Christianity, seem to be more organized around the receipt of rewards in distant space and time (heaven). Is it possible that Buddhism and Christianity represent different orientations of the brain's organization of space and time? That is, do you think Buddhism might be more organized in perispersonal and ambient-extrapersonal space, whereas Christianity is more organized within focal and action extrapersonal space?
Previc: While I am not familiar with Buddhism as much as Christianity, I believe that formal, ritualized concepts of heaven and eternity are generally less significant in Buddhism, but the Buddhist belief in and practices to obtain transcendence also oppose the immediate demands of our body, albeit in a different way. So, I would think that both religions (and presumably most if not all religions) embrace extrapersonal themes.
Brack: Connecting your four-realm theory of 3-dimensional space with religious behavior was truly a remarkable insight, and a quantum leap in the theory of religiosity. How did you come up with this? Did you have a long standing interest in religion? Was it just something that hit you out of the blue? Given the uniqueness and diversity of your many theories, it seems like you enjoy taking completely new directions and mental approaches compared to the prevailing views of your contemporaries. Is that a fair assessment?
Previc: The application of my four-dimensional neuropsychological theory of space to religious behavior occurred a few years after its publication in 1998, although I did allude in that paper as to how the primarily dopaminergic ventral areas dealing with extrapersonal space might be involved in even more spatially and temporally distant concepts such as “heaven” and “eternity”. And, I was aware of the religious themes so often reported by paranoid schizophrenics, in concert with the well-documented overactivation of dopaminergic pathways of the left hemisphere in that disorder. In the early part of this decade, some seminal findings of Newberg and others really advanced our understanding of the brain areas involved in religious experience and pointed to a greater ventral prefrontal and temporal-lobe involvement, so I began an extensive review of the neuropsychology (and particularly neurochemistry) of religious behavior. One important aspect of the theory I ultimately presented was the association of “religious experience” systems in the brain to those underlying a variety of extrapersonal states (including dreaming and hallucinations) in which a de-emphasis on tactile and other bodily sensory inputs occurs. Hence, religious systems, like most other brain systems, are not unique in and of themselves but derive from a more fundamental organization of the brain in terms of how we interact in different regions of space. Perhaps this is what most other neuropsychological theorists are less willing to accept. It is the same with my evolutionary theories of human intelligence – rather than focus on the evolution of intelligence or language per se, as many theorists have done, I see more fundamental physiological changes at work that produced a variety of uniquely human traits.
Brack: This brings us to the riddle of atheism. The human brain seems to be supporting quite a spectrum of religious beliefs, from religious obsession to atheism. What is your current thinking on the neurological correlates of atheism?
Previc: In contrast to the fair amount of research into the neuropsychology of religious experience and behavior, especially in recent years, there has been very little investigation into the neural and other correlates of atheism. Humans do not have a predisposition to religion per se, but only a dopaminergic drive towards distant space and time and in predicting and associating stimuli and events therein. Religious and scientific belief systems both provide frameworks for exploring and understanding the world around us; however, activation of the medial-dopaminergic pathways is associated with a more creative or mystical interaction with extrapersonal space, whereas activation of the lateral-dopaminergic system results in a more strategic or analytic interaction (e.g., executive intelligence). I would propose that most atheists have a greater lateral-dopaminergic activation and that even when experiencing altered states, strange coincidences, out-of-body experiences, etc., they are more likely to interpret them from a nonreligious perspective. An analogy is how religious perspectives influence the experience of dopaminergically mediated obsessions – although widespread across the world, obsessions are more typically religious in nature in highly religious societies (such as those in the Middle East) whereas they tend to be more of a sexual or other nonreligious variety in more secular Western societies.
Brack: The correlation between religiosity and political conservatism seems to make your dopamine-spatial theories on religion transferable to political disposition as well. What are your thoughts on this?
Previc: I am not sure how much dopamine influences political persuasion in modern societies. While it is true that there is a general relationship between church attendance and political affiliation, only a subset of churchgoers have had what may be described as a true religious experience. Historically, many major political movements on both the left (e.g., civil rights) and right (e.g., anti-communism) have had religious underpinnings. Also, I am not sure how most other traits associated with dopamine (achievement orientation, internal locus-of-control, executive intelligence, risk-taking, etc.) differ among individuals of different political groups. It is more likely that leaders of whatever political persuasion have higher dopamine levels than the average member of a political party and that most members of modern industrialized societies, regardless of their political persuasion, are higher in dopamine than those in more traditional agricultural societies.
Brack: To quote your paper, The role of extrapersonal brain systems in religious activity: "religious experience and practice in humans are a consequence of the expansion of the dopamine-rich ventral brain systems that, in other mammalian species, mediate behavioral interactions with the most distant portions of the surrounding 3-D space". You seem to be implying that the religious are much more likely to seek rewards in distant space and time (i.e., heaven), and the dopamine system is actually responsible for their ability to accept delayed rewards. You mention this reward-delaying feature of dopamine in your new book. Is religious morality primarily influenced by the dopamine system's orientation towards reward, distant space, and distant time?
Previc: Morality and moral systems are a very complicated issue. To a certain extent, rules of conduct are required in any social species in order to maintain order. But, while young children and even apes have developed primitive moral systems involving immediate rewards and punishment, the more complex moral systems in humans involve abstract (conceptually distant) rules and temporally removed (e.g., future) consequences. Although religious belief systems are compatible with and even dependent on the features of our dopaminergic mind, not all dopaminergic minds and personalities are religious. Indeed, general moral tenets are similar across all religious and secular societies, although many specific tenets (e.g., punishment for adultery and abortion, constraints on lending practices, etc.) vary greatly among world religious denominations.
Brack: In your new book, you discuss the relationship between mental disorders, such as schizophrenia and mania, with hyper-religiosity. A paper by Peters et al., Delusional ideation in religious and psychotic populations, proposed a continuum of delusional ideation that varied in proportion to one's level of religiosity, with those with the highest levels of religious orientation having the highest rates of delusional ideation. The lowest rates of delusional ideation were found in non-religious subjects, while the ordinary religious fell in between these two extremes. Given your substantial research on mental disorders and religious behavior, what are your thoughts on this proposed "continuum"?
Previc: Actually, I have not performed a “substantial” amount of research on religiosity and mental illness—I only reviewed several studies on this topic for my 2006 paper. I do not believe that religiosity per se is associated with mental disorder. There is a tendency for the nonclinical traits of schizotypy and obsessiveness to be mildly associated with religious experiences in normal individuals—but, even though patients with mental disorders may score high on one or both of these traits as well, depending on their condition, one cannot therefore conclude that normal religious experiences and beliefs are also associated with mental disorder. As I recall, Peters et al. (1999) showed no difference between nonreligious persons and mainstream Christians on their scale, which seems to have mostly tapped into schizotypy, although there were some differences for members of smaller religious sects or cults.
Brack: Given the tendency for new religious movements to isolate themselves from secular society and often emigrate, (e.g., the Mormons), what role has dopamine played in the human diaspora out of Africa and across the planet? Are the "promised lands" of the Old Testament an example of the relationship between dopamine, distant space, and religiosity?
Previc: Ancient humans and other species have generally migrated not in order to pursue a “distant ideal”. Many animal species are found across the world, and early Homo habilis is believed to have migrated from Africa into distant parts of Asia. Even the critical diaspora of humans from Africa into Asia around 65,000 years ago may primarily have been to find new sources of food or trade, rather than being propelled by an abstract “exploration drive”. On the other hand, many religious and ethnic diasporas have been forced exoduses due to intolerance, overpopulation and the like. But, clearly a voluntary religious exodus such as the Mormon one to find a “promised land” at least partly reflects a dopaminergic pursuit of a distant ideal.
Brack: As you suggest in your book, the United States seems to be the "dopamine" capitol of the world, at least based on the high rates of dopamine-related mental disorders you discuss. Why do you think America is on an accelerated dopaminergic uptrend?
Previc: Autism is rising throughout the industrialized world, in contrast to the low rates found in the developing world and in simpler cultures within the industrialized world (such as the Amish). It is also rising dramatically in rapidly industrializing nations such as China and India. But, as the economic leader among the industrialized nations, the U.S. has the most competitive and fast-paced economic system with the longest workweek in the world and a high degree of economic and social uncertainty, all of which promote high levels of dopamine. The U.S. also most possesses many other features of modern societies that have also been clearly linked to autism—older maternal age, high levels of cesarean births, high levels of sleep deprivation, etc. Just as it was once thought preposterous that humans and their societies could change the Earth’s climate, so, too, was the notion dismissed that the types of society could have a major influence on the prevalence of mental disorders. But, the data clearly indicate that the hyper-dopaminergic disorders are most present in the industrialized nations, led by the U.S.
Brack: Is the accumulation, modification, and transmission of culture predominately managed by the dopamine system? If so, how does a dynamic technological culture curb its propensity to drive dopamine levels? And where does it all end? Are the mental disorders associated with the hyperactivity of the dopamine system a countervailing force for these cultures, in that these disorders effectively eliminate the ability to further participate in these cultures?
Previc: Part of “cultural transmission” does not involve neural factors—simply, the postnatal transmission (both explicitly and implicitly) of cultural traits and knowledge and the part most easily changed. The other part is the neural transmission of human culture—in my opinion, mostly epigenetic and therefore also amenable to change. However, change only occurs after a recognition that it is needed—and we are not there yet. Even in the case of autism, which has dramatically risen and has convincingly been linked to prenatal influences—leading researchers continue to maintain that there is no true rise in its incidence and that it is almost entirely genetically determined. Even as autism is overwhelming the social services budgets of many states, there is still no widespread acceptance that it can be prevented, let alone that the prevention may involve changes at the core of our societies. And, as far as the environment is concerned, although there is growing acceptance that human-induced climate change is occurring, there is not a serious consensus that, beyond a few technological improvements, the actual structure of society has to change. Part of the problem is that dopaminergic societies, like dopaminergic individuals, have delusions of control and believe that they can control things more than they can. So, where will it all end? The problems I discuss in Chapter 7 of my book will undoubtedly worsen significantly before serious societal change is undertaken—but, the “good news” is that our dopaminergic minds are not set in stone and that eventually we can restore balance ourselves and our societies.
Brack: Edward O. Wilson once remarked "If the brain evolved by natural selection....religious beliefs must have arisen by the same mechanism." What are your thoughts on the role of natural selection in religious beliefs?
Previc: First of all, I believe that most human intellectual evolution (at least since the rise of Homo habilis 2-2.5 M years ago) may not even have been caused by genetic changes. This is not to say that there haven’t been continuous changes in the human genome since then, but merely that these have not contributed to the intellectual uniqueness of humans to the same extent as epigenetic factors such as diet. Even in the case of epigenetic selection, change sometimes occurs even when it is not directly selected for (e.g., Gould and Lewontin’s “spandrels”). A great deal of our uniquely human traits and behaviors may have been part of a general expansion of dopamine that, much like a hydraulic fluid flows to all brake compartments, ended up promoting a whole host of dopaminergically mediated traits. For example, if an increase in dopamine expanded our sense of space and time, it would seem only natural for it to increase a drive for explanations and connection with that space—whether it be religious or scientific. It is not that religion or science were directly selected for or even dopamine per se—rather, an increase in dopamine was an outcome of an improved diet that increased longevity, increased population, and promoted increased cultural exchange in addition to expanding our intellect. So, I definitely reject that notion that religious beliefs in humans are a direct product of natural selection.
Brack: To review, you believe that religious belief is a by-product of the epigenetically-influenced expansion of the brain's dopamine systems in mediating our behaviors in distant space (and time). Is that an accurate summary?
Previc: Yes, with the caveat that some genetic adaptations occurring in Homo habilis 2-2.5 M years ago are believed to have increased our physical endurance capability and thermal tolerance and led to a more carnivorous diet, all reflecting or contributing to increased dopamine levels relative to other hominids. But, this early dopaminergic expansion occurred long before religious beliefs emerged in modern Homo sapiens.
Brack: In your book, you discuss the predominance of dopamine (and acetylcholine) in the left hemisphere, and serotonin (and norepinephine) in the right. You also discuss the serotonergic inhibition of dopamine release as being the most "clinically important neurochemical interaction in the brain". What are your thoughts on the divergent roles of dopamine in the left and right hemispheres? Is dopamine performing similar functions in both hemispheres?
Previc: Dopamine is probably performing similar roles in both hemispheres but it is not the dominant transmitter in the right hemisphere of most humans; hence, the earthier, more emotionally astute, and more peripersonally oriented right hemisphere reflects the predominance of mainly noradrenergic but also serotonergic circuits.
Brack: As you have noted in your work, people are more likely to believe in God than in the Devil or the afterlife. What might explain this interesting asymmetry in human religious belief?
Previc: I hesitate to try to answer this, not being an expert in religion. But, psychologically, there are several reasons as to why people are more likely to believe in God than an afterlife or the Devil. For one, it is difficult to conceive of what an afterlife, be it Heaven or Hell, would be like—first of all, it would be permanent and forever (difficult to conceive or accept, especially in our ever-changing world), and there are so many different conceptions as to what the afterlife really is (some with sexual connotations, some without). I am reminded of a “Twilight Zone” episode I once saw in which a small-time criminal after his death ended up in a place where he had all the money, women and power he wanted. Although initially thrilled, he eventually became totally bored and then outright depressed. He remarked that “he didn’t realize Heaven could be so miserable” until his guide replied, “Who said this was Heaven”? For our dopaminergic minds, it is easier to imagine and accept, however imperfectly, a place located in a higher plane containing cool waters and the like (note dopamine’s role in thermal tolerance) than a hot, tortured place inside the Earth, ruled by the Devil. The Devil, far from being a universal feature of modern religions, is especially hard to accept because it is such a negative concept and antithetical to those who traditionally believe in second (or more) chances in life. The concept of God, especially a personal one, is much more positive: an all-powerful and all-knowing entity who helps us deal with unknowns (unknowables?) in the Universe and in our lives. A personal God in particular helps us in controlling our life and in explaining the many seemingly beneficial coincidences that occur, which tie into the dopaminergic traits of “internal locus-of-control” and remote associationism.
My sincerest thanks to Dr. Fred Previc. Fred's email address is: fprevic@sbcglobal.net
Charles Brack, September 2009
