The Mechanisms of Psychedelic Visionary Experiences: Hypotheses from Evolutionary Psychology

Michael J. Winkelman

Frontiers in Neuroscience, 2017, 11, article 539, 1-17.

doi: 10.3389/fnins.2017.00539

 

Neuropharmacological effects of psychedelics have profound cognitive, emotional, and social effects that inspired the development of cultures and religions worldwide. Findings that psychedelics objectively and reliably produce mystical experiences press the question of the neuropharmacological mechanisms by which these highly significant experiences are produced by exogenous neurotransmitter analogs. Humans have a long evolutionary relationship with psychedelics, a consequence of psychedelics’ selective effects for human cognitive abilities, exemplified in the information rich visionary experiences. Objective evidence that psychedelics produce classicmystical experiences, coupled with the finding that hallucinatory experiences can be induced by many non-drug mechanisms, illustrates the need for a common model of visionary effects. Several models implicate disturbances of normal regulatory processes in the brain as the underlying mechanisms responsible for the similarities of visionary experiences produced by psychedelic and other methods for altering consciousness. Similarities in
psychedelic-induced visionary experiences and those produced by practices such as meditation and hypnosis and pathological conditions such as epilepsy indicate the need for a general model explaining visionary experiences. Common mechanisms underlying diverse alterations of consciousness involve the disruption of normal functions of the prefrontal cortex and default mode network (DMN). This interruption of ordinary control mechanisms allows for the release of thalamic and other lower brain discharges that stimulate a visual information representation system and release the effects of innate
cognitive functions and operators. Converging forms of evidence support the hypothesis that the source of psychedelic experiences involves the emergence of these innate cognitive processes of lower brain systems, with visionary experiences resulting from the activation of innate processes based in the mirror neuron system (MNS).

Keywords : psychedelic, cognition, mysticism, shaman, consciousness, neurophenomenology, mirror neuron system

 

INTRODUCTION

Institutionalized use of psychedelics in religions of pre-modern societies worldwide reveal the central roles of these substances in the evolution of spiritual experiences, cultures, and religions (Schultes et al., 1992; Rätsch, 2005; Rush, 2013; Ellens, 2014; Winkelman, 2014; Winkelman and Hoffman, 2015; Panda et al., 2016). The role of psychedelics in human evolution is indicated by evidence that psychedelics bind to human serotonergic receptors with a higher affinity than they do to those receptor systems in other primates (Pregenzer et al., 1997). The reasons for the roles of psychedelics in cultural evolution are revealed by neuropharmacological research on psychedelic effects on brain processes. The interaction of psychedelics with the innate structures of the human brain produces novel forms of information and integrative cognitive processes (Carhart- Harris et al., 2014b; Froese, 2015; Gallimore, 2015). This suggests that psychedelic substances operated as environmental factors selecting for an enhanced capacity for specific forms of information processing.

The neuropharmacological dynamics of psychedelics are central to understanding the nature of spiritual experiences. Psychedelics are associated with pre-modern religious forms and the early history of the currentmajor world religions (Winkelman and Hoffman, 2015). Furthermore, there is evidence established by double blind clinical studies that spiritual experiences are directly caused by neuropharmacological effects of psychedelic substances (Griffiths et al., 2006, 2008, 2011). Why should the pharmacological effects of psychedelics so consistently produce such significant experiences? What neuropharmacological mechanisms produce these powerful visionary experiences?

While neuropharmacology is conventionally conceptualized as the study of the effects of drugs on behavior, the ultimate goal must also offer some explanation of how drugs have effects on people’s experiences. Why do psychedelics produce the kinds of experiences that lead to the foundation of cultures and religions? How do the pharmacological effects so reliably and quickly produce the kinds of experiences that mystical devotees spend a lifetime pursuing for just a glimpse of these alleged eternal
truths?

Some might consider the answers to these questions to be beyond the purview of neuropharmacology, perhaps best left to philosophers. But a mature neuropharmacology ought to be able to offer a cogent explanation of how it is that the neurochemistry of an exogenous compound produces activity and functional modifications in the brain that lead people across time and place to report experiences of a profoundly spiritual nature, often with great significance to the individual and even society.

A neuropharmacological explanation of psychedelic effects on human experience can be found in the approach of neurophenomenology, “a research programme aimed at bridging the explanatory gap between first-person subjective experience and neurophysiological third-person data, through an embodied and enactive approach to the biology of consciousness… {N}europhenomenology is then viewed as a novel scientific method building on a corpus of intersubjectively-invariant firstperson reports thatmay broaden the horizon of objective science” (Khachouf et al., 2013, p. 1). We need to know what is being experienced in order to identify what it is we are ultimately trying to explain.

Neurophenomenology is an approach to the understanding of the structure and content of phenomenal experience in terms of principles operating at the neurological level (see Laughlin et al., 1992; Varela, 1996; Thompson and Varela, 2001; Thompson, 2007). Or in other terms, the first person perspectives of personal experience are explained by reference to some homologous causal features identified by third person perspectives on brain operation. If what people experience ought to be explained in terms of pharmacological actions, then psychedelics are an excellent example of this challenge presented
to neuropharmacology.

The experiences to be explained are not just some debatable philosophical construct but an objective domain of experience revealed by empirical evidence. A variety of research projects provide converging findings that confirm the empirical nature of the domains of altered states of consciousness (see Preller and Vollenweider, 2016 for review). These domains of human experience are assessed through psychometric instruments such as: the Altered State of Consciousness Questionnaire (Dittrich et al., 1985; Dittrich, 1998), later modified as the APZOAV (Dittrich, 1998); the Phenomenology of Consciousness Inventory (Pekala et al., 1986); the Hallucinogen Rating Scale (Strassman et al., 1994; Riba et al., 2001); the Mysticism scale (Hood et al., 2001); the Mystical Experiences Questionnaire
(MacLean et al., 2012; Barrett et al., 2015); and the Five Dimensions of Altered States of Consciousness (5D-ASC; Studerus et al., 2010). These studies provide empirical evidence of common core dimensions to experiences of pharmacologically and non-pharmacologically induced alterations of consciousness.

If the ultimate goal neuropharmacology includes an explanation of the nature of first-person psychedelic experiences in terms of pharmacological, neurological and functional brain mechanisms, what is this experience to be explained? What is the nature of psychedelic experiences? There are number forms of psychedelic experience, exemplified in differences in mystical and shamanic psychedelic experiences
described below. The empirical data regarding these experiences are startling and perhaps even confusing for the following reasons:
1) Psychedelics reliably elicit experiences that are virtually indistinguishable from mystical experiences induced through prolonged austerities and disciplined contemplative practice (Smith, 2000; Richards, 2016; Yaden et al., 2017); and
2) In contrast to the mystical features of psychedelic-induced experiences, psychedelic use in pre modern shamanic cultures produced a distinctive worldview characterized by animism, an experience of transforming into an animal, and the perspective of entheogens, viewing these substances as
generating experiences of spiritual entities within the person and environment (Dobkin de Rios, 1984;Winkelman, 2013b).

The differences in psychedelic-induced mystical and shamanic experiences illustrate that while these substances reliably produce certain kinds of experience, the forms of experience may vary considerably—one agent, variable experiences. Secondly, the similarity of psychedelic and non-psychedelic mystical experiences suggests that the explanation of psychedelic experiences is not through mechanisms unique to psychedelics, but rather through shared mechanisms affected by non-drug procedures.

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