On the Self and Consciousness
A phenomenological and neurological review of altered states of
consciousness induced by meditation and psychedelics
María Andrea Arciniegas Gómez
July 2016
Student ID: 10864989
Supervisor: Wouter Boekel, PhD candidate Co-assessor: Michiel van Elk, PhD
Literature Thesis
MSc in Brain and Cognitive Science
T
ABLE OF CONTENTSPage
Introduction 3
Chapter 1: A phenomenological analysis of Altered States of Consciousness induced by
Meditation and Psychedelics 5
Part 1: The Phenomenology of Meditation 6
Table 1: Phenomenological reports of Meditation 7
Part 2: The Phenomenology of Psychedelics 9
Table 2 - Phenomenological reports of Psychedelics 10
Part 3: Commonalities in the phenomenology of altered states of consciousness brought on by meditation and psychedelics (ASCmp) 12
Part 4: The philosophy of the ‘self’: the narrative and experiential self. An epistemic
approach 13
Part 5: The philosophy of consciousness and the hard mind/body problem. An ontological approach
Integrated Information Theory
18 19
Conclusion of the Chapter 21
Chapter 2: Neural mechanisms of Meditation and Psychedelics
Part 1: Neural Mechanisms of Meditation 22
Conclusion 26
Table 3- Review on Meditation neuroimaging literature 26
Part 2: Neural Mechanisms of Psychedelics 28
Conclusion 30
Table 4 - Review on Psychedelic neuroimaging literature 31
Part 3: Commonalities between neural mechanisms of Meditation and Psychedelics 29
Chapter 3 - A Holistic Theory of Consciousness 34
I
NTRODUCTIONhis text revolves around four main concepts; consciousness, meditation, psychedelics and the self. The main purpose is to show how they are related, not only in practice, but also how they are intrinsically connected. Chapter one consists of a philosophical approach to altered states of consciousness induced by meditation and psychedelics (ASCmp). In it, I will briefly expose the phenomenology of the practice of meditation and the use of psychedelics, and analyze it to contribute to the philosophical debate around the self and consciousness, both epistemologically and ontologically. Chapter two consists of a neurocognitive approach to ASCmp. In it, I will disclose their underlying neurological mechanisms, explore their similarities, and analyze what light they shed on the workings of the brain. In chapter three, I compile, organize, and expose an interdisciplinary holistic theory of consciousness. To do so, I will advocate in favor of a mixture of the entropic brain theory, the hypofrontality hypothesis and Integrated Information Theory (IIT), which will be explained throughout different parts of the text. The aim is to account for an integrated explanation of ASCmp that can help explicate how consciousness works in the brain and, possibly, how consciousness itself relates to the physical world and reality.
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Historically, consciousness has been one of the greatest mysteries of human endeavor. There has been a long succession of theories about what it is, how it works, and why it exists that come from different traditions. Philosophers have dwelled on it since the beginning of civilization, and every form of religion or spiritual practice seems to have put forward an answer to such questions in one way or another. The scientific community has intermittently attempted to join the discussion facing a lot of resistance in the process, not because there is a lack of interest, but a lack of proper conceptual knowledge and agreement on the matter and, consequently, adequate tools to grasp it due to its seeming intangible nature (Chalmers, 1995).
Parallel to this human interest in consciousness, similar steps have been taken around meditation. Ancient in origin, meditative practices have also developed in different ways depending on the surrounding culture. The most developed canon was produced about 2500 years ago in east by the Buddhist tradition, which managed to create rich and extensive content explaining what meditation is, how it works psychologically, and why it is a good practice (e.g., Ingram, 2008; Stcherbatsky, 2003). Although most studies on meditation have been done by eastern philosophers, the modern western scientific community has taken a somewhat recent interest on it, elucidating the neural mechanisms, effects and benefits during (states) and after (traits) practice of some of these techniques (e.g., Fox et al., 2014, see Chapter 2, Part 1).
Lastly, psychedelics have had a somewhat more obscure, yet perhaps more prominent, interest throughout time. Psychedelics (from the Greek, “mind-manifesting”) is the term used to categorize a subset of psychoactive drugs that alter perception and cognition in a wide arrange of forms. The classic psychedelic drugs are mescaline (e.g., peyote and san pedro cacti), psilocybin (“magic mushrooms”), LSD, and DMT (ayahuasca; Wasson, Kramrisch, Ott, & Ruck, 1986). Some of these have been used for religious ceremonies, recreational purposes and medical treatments by many cultures for at least the last 5000 years (Wasson et al., 1986). Unfortunately, psychedelics have become taboo in many cultures, and the scientific initial enthusiasm on researching the different psychoactive substances that started in the 50’s was cut off by governmental prohibition at the end of the 60’s (Cohen, 1994). In the past few years this stigma has somewhat faded inside some academic groups, where research with psychedelics has begun once again, although not without facing hefty scrutiny and regulations (Novotney, 2010).
Both meditation and psychedelics are notably famous techniques that have spread because of their use in altering consciousness. While psychedelics offer a quick and powerful route, meditation requires a lot of practice and proficiency before experiencing any strong shift in consciousness beyond the relaxing, clearing and tranquilizing more immediate effects. Most notably, the peak experiences reported in both refer to achieving a “higher” state of consciousness, also called “expansion” or “shift” in consciousness, characterized particularly by a deep alteration in the concept of the self (see
Chapter 1, Part 1 and 2). The study of the self has been the center of multiple philosophical theories
throughout time, and has traditionally been connected to consciousness, awareness, and agency (Gallagher & Zahavi, 2008). Although we will expand on this in Chapter 1, when a person experience a self-related experience (like those reported in ASCmp), it tends to have a huge psychological impact on the experiencer, usually classified as “spiritual”, “transcendental” or “mystical”. It seems like this subjective study of our own consciousness and its contents is the basis of spiritual life. Nevertheless, “spirituality”, much like “consciousness” is still a concept rejected by science in general as it poses a challenge even just to define it, much more so, to understand it1.
These peak experiences open the question as to what can a phenomenological study of the self in altered states of consciousness (ASC) tell us about who we are and the nature of our minds. Do they share some features? Could those phenomenological similarities rely on a common neural basis? And in that case, how does it work? Are some regions of the brain in charge of regulating the state of consciousness we are in? This interdisciplinary approach between phenomenology and cognitive neuroscience may be crucial to achieving a complete understanding of consciousness, ourselves and reality. After all, the study of the self and consciousness cannot be done without knowing what it is
1 Another problem with this concept of “spiritual” is the widespread connection between spirituality and religion, although at its core, they
that we want to explain. Phenomenology pertains to the study of the experienced phenomena (the qualia), a key ingredient in the study of the structure of such experiences in the first-person-perspective, and so it can help to define it. Neuroscience, then, can build up on that and provide data that we can interpret in light of such structured concepts, tying it together with the neural mechanisms of the brain. This is precisely what I hope to achieve in this text.
C
HAPTER1
A phenomenological analysis of Altered States of Consciousness induced by Meditation
and Psychedelics (ASCmp)
The aim of this chapter is to explore the phenomenology of altered states of consciousness (ASC) induced by meditation2 and psychedelics (ASCmp) and discuss how these experiences can
contradict or support some of the stances in the philosophical debate around the self and consciousness. To accomplish this I will expose some reports by practitioners of meditation and psychedelics users and their commonalities regarding to experiences around the self. Next, I will analyze if the insights of these experiences support or deny the concepts of narrative and experiential self. I will argue that the phenomenology of ASCmp points towards a division in the notion of self and subject that should be implemented in the philosophical debates around this concept. Finally, I will attempt to extrapolate these findings into the field of consciousness research by addressing the ontological and epistemological side of the discussion and show how Integrated Information Theory (IIT) can serve as a coherent framework that accounts for the findings of this analysis and a way to answer the hard mind/body problem of consciousness.
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Brief note on Phenomenology: It is the philosophical study of the subjective experience in the first-person perspective, first proposed by the German philosopher Edmund Husserl in the beginning of the 20th century (Zahavi, 2002). More precisely, it studies the essence of
perception and consciousness by giving a direct description of our experience as it is, without taking into account its psychological origin or any causal explanation (Merleau-Ponty & Smith, 1996).
2Note that we will not focus on Buddhist philosophy per se, due to the large amount of branches, variants, writers and texts that have
formed in the 2500 years of its development. Instead, we will focus on the phenomenological reports of practitioners while they are in higher states of consciousness due to meditation. For a full review on the philosophy of Buddhism check Stcherbatsky, (2003)
Part 1: The Phenomenology of Meditation
Throughout the last 2500 years, meditation practices have been taught traditionally by Buddhism as the core of its philosophy, although Taoism, Hinduism and Jainism are also profoundly influenced by its practice. While the amount of types of contemplative practices is countless, at its core meditation can be defined as a series of mental exercises designed to produce changes in how a person relates to the world. This is done through self-regulation of the body and mind by adopting a specific posture and directing attention to a specific focus-set for long periods of time, which alters mental events (Cahn & Polich, 2006; Kornfield, 1979). Traditionally, undertaking this practice requires the novice to pledge to follow a set of behavioral and conceptual beliefs and the guidance of a mentor, although without dogmatism3. The development of the required skills needed for achieving
a higher state comes gradually with practice, and the complexity of such meditation techniques evolves. The role of the mentor is to assess the level of proficiency reached by its pupil, making sure s/he does not move to a challenge beyond her/his mastered abilities.
In the middle of the 20th century, the scientific community became interested in researching the effects of meditation practice, secularizing the process under the term “mindfulness”. Out of all techniques, mindfulness has become the most common one to be researched (Michael Murphy, Steven Donovan, 1997) and, due to its psychological benefits, it has served as the basis for the development of mindfulness-based interventions (MBI’s) in the clinical field (Lindahl, Kaplan, Winget, & Britton, 2014). But mindfulness needs to be distinguished from traditional meditative techniques like transcendental meditation (TM), Zen, or visualization-meditation, for example. The psychologist and Buddhist monk, Jack Kornfield (1979) emphasized the importance of clarifying the technique being studied scientifically, by exposing the description of the particular set of exercises and goals performed during the experiment, as there are multiple practices that cannot really be included under the ‘mindfulness’ term.
To clarify it, mindfulness comes from the Pali word sati which means “clear awareness”. As a practice, it is the process of attending to natural experiences (thoughts, feelings or sensations) that arise in order to reach a state of clear, nonjudgmental, nonattached and undistracted attention to the contents of consciousness, whether pleasant or unpleasant (Cahn & Polich, 2006; Harris, 2014). In the Buddhist tradition, this practice can classify as belonging to vipassana, which goes parallel to the
3 In fact, the teachings and philosophic postulates of Buddhism are encouraged to be tested out and confirmed by the practitioner during its
style of samatha4. Vipassana is also known as “insight meditation” and is originally explained in the
Satipatthana Sutta, a rigorously empirical guide to freeing the mind from suffering. In short, vipassana is attending the many transient sensations just as they are, so the totality of one’s
experience becomes the field of contemplation. The goal is to penetrate the three illusions, namely; permanence, satisfactoriness and a separate self (Ingram, 2008).
Samatha, in contrast, is the Pali word for “calm abiding” and is known as “concentration meditation”
or “tranquility meditation”. Unlike insight meditation, it focuses on purposefully fixating on a specific mental or sensory activity (a concept, image, sensation [breath] or sound [mantra]) to develop concentration and, eventually, to be able to freeze the mind in a specific state called “jhana” or “dyana”, which roughly means “absorption” (Ingram, 2008). The phenomenological experiences are those of bliss, spaciousness and formlessness, but in itself it does not develop wisdom. Because of this, vipassana and samatha are meant to be trained together, in order to reach higher states of consciousness. Mixing these two plus a variation of goals create almost every meditative practice (TM, Zen, visualization, etc.).
Because of this interconnection between vipassana and samatha, as Kornfield (1979) pointed out, many studies do not make a clear distinction between them, but use a mix instead. That is why, although it is good to keep in mind the existence of these traditional distinctions, we will use the term meditation as an umbrella concept that covers all of the above. In this way, we can continue to gather and summarize the main phenomenological experiences brought on by meditation, as seen on Table 1:
TABLE 1
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Phenomenological reports of Meditation5Visual hallucinations6
Buddhist sources and secular practitioners tend to use it as an indicator of the degree of concentration achieved. With high proficiency comes lights or
nimittas that can be divided into:
Discrete light-forms
4 Insight practices can be various types of vipassana, Dzogchen, zazen, etc. (Ingram, 2008), but for the purpose of this text we will
summarize them as vipassana, as it has usually been done in meditation literature. This helps to distinguish them from the concentration practices or samatha which are the two usual groups to classify most meditation practices
5 The phenomenology of meditation has been gathered from reports taken from different printed sources and not directly, which means that
more precise questions that could have been useful for the purposes of this text could not be answered. This compendium of reports was summarized from Cahn & Polich, 2006; Harris, 2014; Kornfield, 1979; Kozhevnikov et al., 2013; Lindahl et al., 2014; Thanalakshmi et al., 2014; Venkatesh, Raju, Shivani, Tompkins, & Meti, 1997; XIV, Kamalaśīla, & Jeremy, 2003 and Ludwig, 1966; Kornfield (1979); Cahn & Polich (2006); Harris (2014); Kozhevnikov, Elliott, Shephard, & Gramann, (2013); Lindahl, Kaplan, Winget, & Britton (2014); Thanalakshmi, Ravindran, Sembulingam, & Sembulingam (2014); Venkatesh, Raju, Shivani, Tompkins, & Meti (1997); Dalai Lama XIV et al.(2003).
6 Hallucinations can be divided in both simple and complex ones. These visual hallucinations classify as simple, which are basically changes
across the visual field in form of patterns, diffussion or lights and are associated with activity in the occipital cortex, the primary visual-processing center of the brain. On the other hand, complex hallucinations involve many brain areas, including those of memory, and require more widespread and extensive neuroplastic modifications (Ffytche, Blom, & Catani, 2010; Lindahl et al., 2014).
Patterned or diffuse lights (shimmering, pixilation, brightening) Auditory, gustatory and olfactory hallucinations/experiences
Unusual somatic experiences and physiological changes Broad spectrum of reported sensations:
Spontaneous movement Experience of an “energy” flow Changes in weight or temperature7
Changed breathing patterns Strong emotions and mood swings Time and space distortions Cognitive experiences
Deep sense of calm and peacefulness
Cessation or slowing of the mind’s internal dialogue Perceptual clarity
Ineffable states Self-related experiences
Self-transcending love Boundlessness
Expansiveness in the experience of self
Conscious awareness merging completely with the object of meditation
Out-of-the-body experiences
“Peak” experiences (Samadhi, clear-light, nirvana)
A shift in consciousness characterized by a mixture of many of the phenomena mentioned above
Oneness
Blissful absorption into the current moment
For the purposes of this text, we are interested in the self-related experiences and peak experiences that occur on the highest states of consciousness after mastering both concentration and insight practice. This state is often called Samadhi in Buddhism, and is the ultimate goal of most practices8.
Phenomenologically, it is described as “alterations to the notion of self and consciousness”, said to be ineffable by those who reach them, particularly because of the absence of a narrative once the state is reached. Therefore, in samadhi, the Clear-light period, or other peak experiences, there has been a prolonged concentration on a particular object to the point where “reality shifts”; the inner monologue ceases and the practitioner can feel like she ceased to exist as an individual. These self-related experiences are usually described as “self-transcending”, that of “oneness”, a “boundless self”, an
7 There is a special type of meditation called tummo performed by experienced Tibetan Buddhists that has been proven to produce major
temperatures shifts in the body. Using cognitive tools (visualizations of fire within the body) and somatic tools (forceful breath) meditators dramatically increased their body temperature up to 8.3 ° C in peripheral body temperature (fingers and toes) and of 1.9 ° C in the navel and lumbar regions (Kozhevnikov et al., 2013). Other techniques based on control breathing (referred as pranayama) like Sheetali and
Sheethkari are said to bring down the temperature of the body as part of their calming effect.
8 It is worth noting that this altered state of consciousness has been said to be achieved by other methods like sensory deprivation, hypnosis,
lucid dreaming, etc. (Vaitl, Birbaumer, Gruzelier, Jamieson, Kotchoubey, Kübler, Lehmann, Miltner, Ott, Pütz, Sammer, Strauch, Strehl, Wackermann, Weiss, et al., 2005).
“expansiveness in the experience of self”, and the feeling of being a “conscious awareness merging completely with the object of meditation”.
All things considered, in ASC brought on by meditation practitioners reach a point in which the narrative or stream of thoughts of their minds ceases, bringing forth an experience of “clarity” and transcendence. They seem to be able to explore the self and its boundaries and express to have found that there is not any, as this concept of identity dissolves when attentively observed. This results in the experience that the dichotomy between subject and object ceases to exist and the feeling of
self-transcendence takes place. This realization is called Anatta or no-self, which is one of the
understandings about the three marks of existence in Buddhism. As the philosopher and neuroscientist Sam Harris (2014) puts it, when the self is closely examined, it disappears, hence confirming that the sensation of one is merely illusory9.
Part 2: The Phenomenology of Psychedelics
The most renowned psychedelics are:
Psilocybin: Active principle of ‘magic mushrooms’, which encompasses more than 200 species. Psilocybin is converted by the body to psilocin, the tryptamine alkaloid that is responsible for its psychoactive effects.
Mescaline: Active principle of peyote, the root from the Lophophora williamsii cactus, native to the Mexican desert, although some other cactus species also carry mescaline. It is an alkaloid of the phenethylamines’ class. It is now usually chemically synthetized and ingested orally.
N,N-dimethyltryptamine (DMT): Active principle of yagé/ayahuasca, but it can also be consumed in its pure form, either orally of smoked.
o Ayahuasca (“vine of the (dead) spirits” in Quechua) is a mix of a variety of plants to create a brew that must be ingested orally. It is used in shamanic ceremonies of indigenous cultures, particularly those in the Amazon region in South America and it is regarded as a sacred communion with the Divine (Luke, 2011; Shanon, 2002).
o Pure DMT: It has a very fast acting time, it is experienced in a higher intensity and it lasts a shorter amount around 12-15 minutes when smoked or vaporized (Luke, 2011). Lysergic acid diethylamide (LSD): Created by the Swiss chemist Albert Hofmann in 1938.
Part of the tryptamine family, like its cousin DMT and its natural counterpart, LSA (found in Ipomoea tricolor [Morning glory] or Argyreia nervosa [Hawaiian baby woodrose] seeds).
9 This is not the same as saying that the self is useless, as the experience of the self can be (and is) extremely helpful for our actions in our
The specific effects elicited from each one of these may vary according not only the compound, but also the dosage and users individualities, but they powerfully alter cognition, perception and mood. They mostly work by binding to the 5-HT2A serotonin receptors in the brain, among others (see Ray, 2010 for a detailed revision). The effects described cover a great range of perceptual alterations, predominantly in the field of vision and cognition. In Table 2, the effects induced by psychedelics in general are summarized, with a small annotation regarding the specific compound with which the experience took place.
TABLE 2
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Phenomenological reports of Psychedelics10Visual hallucinations
They go from simple to complex hallucinations in both closed and open eyes.
Lights: “Slow dance of golden lights”, “nodes of energy that vibrated with a continuously changing, patterned life” (mescaline, both closed and open eyes). Increased intensity in colors and brightness (DMT, ayahuasca, mescalin). “All glowed with living light“. “Raise of all colors to a higher power and innumerable fine shades of difference, to which, at ordinary times, he is completely blind”. (Open eyes).
Entoptics: Geometric patterns, "moving, brilliantly colored oriental motifs", kaleidoscopic lights or patterns, extra-dimensional geometric visions, or beyond dimensionality (DMT, ayahuasca, mescalin).
Tunnels (ayahuasca). Reported in both closed and open eyes.
Encounter with entities: Encounter with discarnate entities like humans and animals, or supernatural beings like pixies, elves, etc. (DMT, ayahuasca). Reported in both closed and open eyes, usually in high doses.
Auditory, gustatory and olfactory hallucinations/experiences
High-pitched whining and whirring or chattering sounds at the beginning (DMT). Unusual somatic experiences and physiological changes
Rapid increase in pulse (up to 150bpm) and blood pressure at the beginning (DMT, ayahuasca).
Reduction of melatonin concentration in the blood (DMT, ayahuasca). Dilated pupils (DMT, ayahuasca).
Temperature rise (DMT). Vomiting (ayahuasca). Intense physical vibrations (DMT).
Sense of “powerful energy pulsing through the body” (DMT).
Breathing and movement: Things seem to be breathing and constantly moving (Ayahuasca, LSD, psilocybin),
Strong emotions and mood swings Elation
Euphoria Excitement Time and space distortions
Sense of timelessness (DMT, ayahuasca, LSD, mescalin). “My actual experience had been, was still, of an indefinite duration or alternatively of a perpetual present made up of one continually changing apocalypse”.
Interest in the space dimension diminishes (mescalin). “The mind was primarily
10 The compendium of phenomenological reports from psychedelics was summarized from Harris, (2014); Huxley (1952); Leary Metzner, &
Dass (1964); Shanon, (2002); Luke (2011). As well as with meditation phenomenology, these reports had to be taken from different sources and not directly, which means that more precise questions that could have been useful for the purposes of this text could not be performed.
concerned, not with measures and locations, but with being and meaning”. Some report psi phenomena (telepathy and clairvoyance).
Cognitive experiences
The strongest effect of psychedelics in general is what is usually called a “shift in consciousness” (DMT, ayahuasca, mescalin, LSD, psilocybin). Also described as a “change in the realm of objective fact”, “the so-called secondary characters of things are primary” (mescalin), “The infallible mind of the pure mystic state.”
“Awareness of energy transformations with no imposition of mental categories”. “Issness” or the feeling that things are neither agreeable nor disagreeable, but just exist (DMT, ayahuasca, LSD, mescalin).
Revelation Insights Self-related experiences
Dissociation from the body “my awareness of the transfigured outer world was no longer accompanied by an awareness of my physical organism”, “that ‘I’ was not the same as these arms and legs ‘out there’” (DMT, ayahuasca, mescalin).
No sense of a body “dissolving into pure awareness” (DMT, ayahuasca, LSD). Feelings of self-transcendence, and egolessness “there is an ‘obscure knowledge’ that All is in all - that All is actually each” (DMT, ayahuasca, LSD, psilocybin, mescalin).
Feeling of unity (DMT, ayahuasca, LSD, mescalin) “being my self in the Not-self which was the other objects”.
Being out of one’s body and into another dimension (DMT, ayahuasca). Out of body experiences (DMT, ayahuasca).
“Peak” experiences (Samadhi, clear-light, nirvana)
A shift in consciousness characterized by a mixture of many of the phenomena mentioned above.
Oneness
Blissful absorption into the current moment
Again, for the purposes of this text the most important are the self-related and cognitive effects of psychedelics. The strongest effect reported by all users is what is usually called a “shift in consciousness”. Some descriptions of what is then experienced are “a change in the realm of objective fact” and “the awareness of energy transformations with no imposition of mental categories”. The feeling that things are “neither agreeable nor disagreeable”, but just exist, also referred as “issness” of things. In addition, users report a sense of timelessness, were time is irrelevant and eternal at the same time. When these experiences are taken in the right direction11, they usually entail some mayor
self-related insights. Users describe feeling transcendence from the body: “my awareness of the
transfigured outer world was no longer accompanied by an awareness of my physical organism”, or “that ‘I’ was not the same as these arms and legs ‘out there’”, having “no sense of a body”. They also describe their sense of self to be altered as they feel like “dissolving into pure awareness”, “egolessness” and “ego death”. This usually is accompanied by sensations of unity: “there is an ‘obscure knowledge’ that All is in all - that All is actually each”, feelings of “oceanic connectedness
11 Psychedelic experiences are affected by the subjective psychological state of the subject and her surroundings, so in the wrong combination, users can also report having bad or frightening experiences.
to the universe” and “total blurring of boundaries between self and other”. Some even describe some out-of-body experiences like being into another dimension. These experiences are usually accompanied or followed by feelings of compassion, elation, euphoria and excitement and, like meditation, are reported to bring revelation and insights. Although some differences between substances are reported by experienced users, most of these experiences can be achieved by using any psychedelic compound; in a way, having those effects is what distinguishes psychedelics from narcotics like heroin or stimulants like cocaine.
Part 3: Commonalities in the phenomenology of altered states of consciousness induced by meditation and psychedelics (ASCmp)
It is remarkable how ASCmp can share many of the same experiences. They show to be capable of stimulating profound existential experiences, always in relation to the notion of the self, consciousness and reality, which can leave a lasting psychological impression. Users and practitioners usually report having learned about impermanence, interconnectedness and the clear first-hand evidence of the self being an illusion. After having tried both methods, Harris (2014) explains the self-transcendence experience like this:
In fact, when I pay attention, it is impossible for me to feel like a self at all: The implied center of cognition and emotion simply falls away, and it is obvious that consciousness is never truly confined by what it knows. That which is aware of sadness is not sad. That which is aware of fear is not fearful. The moment I am lost in thought, however, I’m as confused as anyone else. In subjective terms, you are consciousness itself—you are not the next, evanescent image or string of words that appears in your mind. Not seeing it arise, however, the next thought will seem to become what you are. It may take years of observing the contents of consciousness—or it may take only moments—but it is quite possible to realize that consciousness itself is free, no matter what arises to be noticed (Harris, 2014, p. 137).
Harris further explains that the difference between meditation and psychedelics can be portrayed in the analogy of slowly climbing up a mountain in the former, as opposed to being strapped on to a rocket in the latter. Other academics like the psychologist Timothy Leary have also commented on the similarities in the experiences, when he and his colleagues re-interpreted the Tibetan Book of Death in light of the psychedelic experience (Leary, Metzner, & Dass, 1964).
As can be seen from the phenomenology of ASCmp, we can deduce that there are shared self-related experiences that focus on (i), the constant change and impermanence of thoughts and sensations (ii), the potential of transcending the language or narrative of thoughts and (iii), feelings of unity that
come from the dissolution of the subject-object duality. All these together seem to form the experience of (v), transcending the feeling of a bounded permanent self.
Part 4: The philosophy of the ‘self’: the narrative and experiential self. An epistemic approach
What can these insights contribute to the philosophy of the mind? Let us begin by going through some of the basic elements of the debate around the self. Broadly speaking, two different levels or types of self have been formulated: self as a narrative construct and self as an experiential dimension. The narrative-self (NS) evolves across the lifetime of the organism and uses language and memory to develop. The experiential-self (ES), or core-self, is pre-linguistic and remains stable across lifetime, constantly accommodating to changing experiences (Gallagher & Zahavi, 2008). This distinction can be merged with the concepts of reflective self-awareness and pre-reflecting awareness, respectively, or those of the self as an object (‘me’) or the self as a subject (‘I’) (Gallagher, 2000; James, 1892). In all of these, the former has the ability to think about itself, while the latter is just being a subject of conscious experience.
Phenomenologists like Edmund Husserl, Jean-Paul Sartre, Maurice Merleau-Ponty, Dan Zahavi, Shaun Gallagher and Antonio Damasio argue in favor of a non-reductive stance of the mind, that is, from an epistemologically approach the mind cannot be reduced to its physiological components, so they argue in favor of the existence of the self. Although each of their theories differ in many aspects, in essence, they propose that there is an ES that serves as the basis for the subjective first-person perspective (Damasio, 2010; Gallagher & Zahavi, 2008; Merleau-Ponty & Smith, 1996). This ES is not a product of narrative practices, but an integral part of the structure of consciousness that gives ownership to the experiences. The NS builds on top of it and could not be formed without it. In this line of thought, it is necessary to study this ES if we want to understand the mind.
In contrast, philosophers like Thomas Metzinger, Patricia Churchland, Paul Churchland, Daniel Dennett and Kristina Musholt take a reductionist or eliminative stance of the mind and propose that the self is not an integral part to understanding the mind (Churchland, 2002; Dennett, 1993; Metzinger, 2009). They argue in favor of the concept of the NS as being a model or simulation constructed by the brain to have a coherent image of reality (Metzinger, 2009). As Dennett puts it, the self serves like centers of gravity in physics; they are abstractions we postulate to help make sense of behavior of complex things (Dennett, 1993). This NS evolves through the lifetime of an organism but it is just a posit. So far, this argument is similar to the one exposed in the previous approach, but it goes further and also argue that, in our understanding of consciousness, we don’t need to talk about neither the NS nor ES. Since there is no thing, no indivisible entity either in the brain or a
metaphysical realm, the self is a fiction we can let go altogether in our studies. The conscious experience of ‘being a self’ emerges in a transparent way; you see with it but cannot see it. It is just the content of a transparent self-model activated by the organism’s brain (Metzinger, 2009).
Now, what light can the phenomenology of ASCmp cast on these approaches? The ASCmp seem to confirm that all the narrative that forms the autobiographical self can be altered and even transcended at one point; once the consistency of thoughts is interrupted and there is no longer a sense of past or future, the experience of being a self dissolves. In other words, once there is no coherent story that language can account for, the subject stops feeling separate from the rest, as the loss of identity and ownership of thoughts takes place. Both reductionist and non-reductionist theories seem to agree that this type of self –the NS– is just an illusion, a construction or simulation crafted by the brain.
Conversely, phenomenologists still posit the existence of a pre-reflective ES that accounts for the subjective character of the experience. It can be argued that, although the reports from ASCmp are about the concept of the self dissolving, they usually refer to the experience of that self-transcendent state. Even when no self or ego12 is being experienced as the owner of the experience, they are still
capable of having those experiences, and they belong to no one else. In other words, beyond any phenomenology of a self there is still something that is being experienced from a point of view, no matter how fast it changes, how ineffable or abstract; there is qualia13 and there is a subject. But if this
is the case, can these experiences still be said to be part of the experiential-self? Why should we still call it a self when evidence shows there is no longer one? Who is the observer during the experience of self-dissolution or self-transcendence?
Reductionists see no value in considering further evidence brought on by introspection into account (Dennett, 2011), so they do not consider what is being experienced during ASC as relevant to explaining the mind. For them, phenomenology is just an ongoing process made from the content of the simulation the brain creates; an “unwitting fictions of sort” (Dennett, 2011). The self is a narrative construction and consciousness is, therefore, the biological phenomenon of the appearance of a world (Dennett, 2011; Metzinger, 2009). In contrast, phenomenologists interpret this basic core of awareness as the ES, an important element in the explanation of subjectivity and consciousness. For them, without a notion of a permanent pre-linguistic self there is no basis in which the NS could even be built on; it gives the basis to organize all those experiences into one sense of “I” (Gallagher & Zahavi, 2008).
12 Ego and self will be used interchangeably in this text.
13 Qualia is a philosophical term used to define non-reducible individual instances of subjective experience, like the “redness” of an apple,
To link this with the phenomenology of ASCmp, it is useful to analyze the reports that sustain that, in some of the peak experiences, there are moments in which the subject can lose all sense of being or
experiencing something, and just feel like “returning” to normalcy some time after; much like being
on surgical anesthesia, they have no experience from what happened, just notice it when coming back from it. This fact emphasizes the debate on the aspect of subjectivity and, with it, the question of what exactly are we defining as an ES. For the reductionists, this absence of any kind of experience is proof that any type of subjective experience comes forth only by the simulation of the brain which is “turned off” on those states, just like when we are sleeping (Metzinger, 2009). Nevertheless, phenomenologists argue that this does not solve the problem of subjectivity; the fact that even that lack of awareness is tied and then made part of the experience of a single person accounts for the existence of the ES; it is the key element for having a flowing first-person perspective.
Consequently, phenomenologists argue in favor of incorporating the phenomenological method into scientific research as a valid and helpful tool to gather evidence to address issues like consciousness, which holds subjectivity in its core (Musholt, 2013). John Searle puts forward one of the classical arguments in favor of the irreducibility of consciousness (Searle, 1998). As he puts it, there are three features common to all conscious states: they are internal processes (i.e., those they happen inside the body), that have a qualitative aspect to them (i.e., there is a ‘like-to-be’ quality in that state)14 and are
ontologically subjective in the sense they exist as experienced by a human or animal subject. If by trying to understand the mind we lose the qualitative or subjective characteristic of these states, we are losing part of the essence of the phenomena we are trying to explain. In his words:
[O]nce we explain the causal basis of consciousness in terms of the firing of neurons in the thalamus and the various cortical layers, or, for that matter, in terms of quarks or muons, it seems we still have a phenomenon left over (…). Consciousness has a first-person ontology, and we cannot for that reason perform a reduction on consciousness that we can on third-person phenomena, without leaving out its essential character (…) [T]he whole point of having the concept of consciousness in the first place is to have a name for the subjective first-person phenomena (Searle, 1998, p. 55, 57).
This phenomenon is a special one, because consciousness can only be studied precisely through conscious states. Within this phenomenon, to understand the self is relevant since it could give a better understanding of the way consciousness works. It is no wonder, then, that we encounter the problem of defining carefully these different concepts; what an ES is and how complex it can be.
The philosopher Miri Albahari makes a distinction between self and subject that intends to remedy the confusion about the ES. Much like we did, after an analysis on early Indian Buddhism, Albahari (2006, cited from Henry & Thompson, 2010) concluded that the self, as a bounded subject that is a personal owner of experiences and a controlling agent of actions, is an illusion and proposes a
non-egological view of consciousness. This view holds that there is no ego or self that possesses attributes
of ownership and executive control, and the concept of self arises from a process of identification with transitory mental and bodily experiences as ‘me’ or ‘mine’, due to the fact that we are embedded in a body. That is, the concept of a self is a creation that comes from the fact that experiences are localized in a specific time-space. To make it clear, Albahari sustains that the body of the subject is not to be taken as something the subject owns, but as a constituent of the subject in itself. She also affirms the experiential reality of a ‘witnessing subject’, so she seems to agree with a notion of a pre-reflective awareness that does not entail the concept of a self. Subjectivity, then, comes solely from the fact that there is a body or a subject that is in itself embodied; a bodily-subject (Henry & Thompson, 2010). The self, as a concept, should be used only to refer to the NS, and not the bodily-subject, as this raises confusion in the mind-debate.
ASCmp experiences can account for this distinction between the subject (body) and the self. To emphasize, the experience can be said to be held by a subject and, in that sense, maintain a subjective experience from a personal point of view. Nevertheless, this doesn’t mean that subjectivity is self-related, as the concept of the self is experienced to be illusory. It can be argued that the problem with the idea of the ES is, therefore, problematic in a semantic level and, thus, it should be reformed as the
experiential-subject: a pre-reflective, non-narrative awareness that does not imply any notion of
identity, ownership or agency. It is an experience that is not self-related, just subject-related in the sense that it is localized on the body of a particular subject, or a first person perspective.
Nevertheless, the philosopher Evan Thompson (Henry & Thompson, 2010) counters this distinction with the following argument:
In order to be a subject of experience even in the minimal sense of ‘witnessing-from-a-perspective’, one must be pre-reflectively aware of oneself as a living body, i.e., one must be a bodily subject (Thompson2007) (…). The phenomenon of pre-reflective bodily self-awareness entails a basic experience of boundedness between one’s subjective body and the phenomenal world with which one is bodily engaged. Consequently, by Albahari’s own criteria, simply being a subject of experience will involve a basic sense of self. (p. 230). As a result, for Thompson, the mere fact that the phenomenological phenomenon is bound to the body implies that the subject must be self-aware and, therefore, involves a sense of self. Nevertheless, what the ASC show is precisely a state in which there can be such boundedness to the body (being a
subject) and still not have any content or experience of self-awareness, if only for one moment. That is, it serves as evidence that self-awareness is different from mere awareness, and it is not required in order to have a subjective experience: a boundedness of experiences to a body means there is a locus for perceived experience, but it is not required for the subject to be aware of itself as a body. This differs from what is experienced in out-of-body experiences, autoscopic or heautoscopy experiences15
since there is still a sense of self in those, just that it has been locally misplaced (Blanke & Mohr, 2005).
Thompsons’ argument faces a challenge, as he has to argue why a bounded experience of sensations must be self-aware, and not simply be (i.e. just awareness). He further defends this claim by stating that this distinction on self and subject can only be made if one holds the self to be, as Sartre puts it, a “product of recollection” making the self an object for reflection and not simply an awareness that is intransitive and reflexive (Thompson, 2010). Then, Thompson argues, distinguishing between the two implies that the self is something more complex than just the sense of being a subject, which he doesn’t consider necessary.
At its core, this terminology debate can only be settled with phenomenological input, as our experiences are the ones which can elucidate if a distinction is necessary between subject and self. Hence, the ASCmp reports become essential, and we see that –even if it is a kind of folk intuition on the self– the experience of self as normally understood is reported to be dissolved. Then, perhaps it is better to name the ES the experiential-subject (ESub), because the self as a concept isn’t found to be fit for explaining the experience and it can obscure the conversation. Therefore, it can be argued that from what we see in ASCpm, there is no need to abandon Albahari’s distinction between self and subject. On the contrary, this distinction is particularly important to describe the phenomenological non-egological character of the experience since, precisely, there is no sense of being aware of being a self in them. The emphasis is that it is possible to be a bodily locus of perception, a bodily subject with bounded sensations of experience without being self-aware of being that bodily subject. It is difficult to explain self-awareness in a pre-reflective manner, because self-awareness intuitively seem to involve a personal feeling of ownership and agency and this is precisely what is lost in the ASCmp. That is the position that will be taken henceforth, but it is understandable if the reader still wants to use the word ‘self’ to describe the ESub, as it is done on some sides of the philosophical mind-debate, although I hope to have given sound arguments towards the distinction.
To recapitulate, I have discussed how the ASCmp phenomenology analysis can affect the philosophy of the self: they seem to confirm the illusory character of a NS, and support the necessity of
15 In out-of-boy experiences the subject experience itself to be outside the body. I the autoscopic experience, the subject experience seeing a
double oh him/herself. The heautoscopic experiences is a mix of the two, where the subject doesn’t really know in which of the two bodies to place him/herself. For detailed definitions of these experiences see Blanke & Mohr, 2005.
modifying the notion of the experiential-self to an experiential-subject, due to difference experienced between the subjective character of being a bodily-subject and being a self. Nevertheless, the reductionist accounts consider phenomenology and introspection to not be a valid method for studying the mind, and either notion of an experiential-self or subject is merely a fiction that should not be entertained while doing research on the mind, as it does not tell us much about consciousness. So, what can these conclusions tell us about the philosophy of consciousness and the hard mind/body problem?
Part 5: The philosophy of consciousness and the hard mind/body problem. An ontological approach.
At this point, it is relevant to distinguish the ontological commitment and the epistemological approach. The reductionist approach is ontologically monist: only the physical exist; there’s no supernatural realm where consciousness lies. This same ontological standpoint is taken by many non-reductionists who aren’t dualists. But the ‘reductionist’ label refers to the epistemological approach as, when presented with the problem of understanding consciousness, they maintain that since the world is purely physical, it can only be investigated as a biological phenomenon. Consciousness is not something that should be studied scientifically from a first person perspective, but only the brain and third-person-perspective methods can be used to research the mind (Dennett, 1993).
The non-reductionist approach, on the contrary, holds that phenomenology is an important tool in scientific research and grants consciousness an epistemological importance. That is, introspection is held as a valuable method to gain knowledge on consciousness and naturalize it. But phenomenology in itself does not imply a specific ontological stance, though many are monists. Some are idealists and sustain that experience or qualia is the core of reality16. The opposite approach, which includes the
majority of current phenomenologist, puts the nature of reality in matter or physical phenomena, just like reductionists.
As argued earlier, there is a strong argument for the epistemic irreducibility of the mind17. If correct,
phenomenology plays a crucial role in a true understanding of consciousness. Our analysis on ASCmp is an example of using phenomenology to try to understand what the self and consciousness are,
16 As this is not a popular theory we will not deal with it here, but focus only on the physicalist or materialist versions of non-reductionists. 17 Previously I put forward an argument in favor of irreducibility but there are also numerous arguments which refute reductionist reasoning.
Succinctly, there are two kinds of reductions, “eliminative” and “non-eliminative”. While the first get rid of the phenomenon by showing it doesn’t really exist and is just an illusion; the second attempts to reduce it saying it can be explained entirely in terms of physical causal basis. The eliminative reduction fails because in the case of consciousness the illusion of being conscious is identical to being conscious, “if it seems to me that I am conscious, then I am” (Searle, 1998, p. 56). The non-eliminative reduction fails because although consciousness is a biological phenomenon like any other, it has a first-person ontology, which make it impossible to be reduced to a third-person phenomena without leaving behind an essential feature.
separating one from the other. So far, we concluded that any notion of a self is illusory, but found evidence in favor of an ESub which holds pre-reflective awareness. Nonetheless, we can still ask how reductionist and non-reductionist account for how and why can consciousness or the mind relate to the physical body; what David Chalmers coined the “hard problem of consciousness”18. This is an
incredibly complex subject, reason why only some remarks will be mentioned, which relate to the analysis on what ASCmp tell us about consciousness.
So far, in both accounts the experiential subjective properties seem to emerge from the physical world. Reductionists cannot and do not want to solve this problem; there is no explanation as to how the brain creates these simulations, or how consciousness as a biological phenomenon can happen in a physical world. This question is even thought to be ill formed, and philosophers like Dennett (2004) openly dismiss it. On the contrary, non-reductionists still grant qualia a place in consciousness, and fields like embodied cognition and enactivism propose a framework to explain how consciousness is an emergent element in complex systems made by the bodily subjects and their environment. From what we have discussed from the phenomenology of ASCmp, we can consider the existence of an ESub. This ESub can be argued to be a way in which consciousness is manifest to itself, that is, although the self is an illusion, there is still a subject who is experiencing and this non-egological or self-less awareness is what constitutes consciousness. In brief, in its most stripped form, consciousness is qualia; just instances of subjective experience. But since qualia are linked to a body (i.e. the ESub), it can be argued that we are claiming that the nature of reality is neither mental nor physical, but both at the same time. That is, matter holds in itself this qualia character, they are inseparable.
There are currently some theories that agree with this conclusion and use it as a way of naturalizing the mind. In here, I will explore the Integrated Information Theory (IIT) which attempts to do so.
Integrated information Theory (IIT)
The neuroscientists Giulio Tononi and Christof Koch (2015) have developed a mathematical19
framework to explain the nature of consciousness by proposing the idea that information and qualia are related. Consciousness is conceptualized as depending on the difference between integration of information that a system of material mechanisms (like the brain) holds. Information is taken as
18 Precisely, why do we have a subjective experience of our life, a phenomenological “what-does-it-feel-like” experience from the
first-person perspective, out of the neurophysiological processes that undergo our daily life? How does consciousness relates to the physical world? This opposed to the “easy problem”, which rests on the ability of process information, control behavior, discriminate stimuli, etc., which can be done by correlational computational or neural analysis.
19 The mathematical approach of IIT aims to the future formalization and quantification of consciousness states and an explanation for the
“differences that make a difference” within the state of a system (Oizumi, Albantakis, & Tononi, 2014) and it can be aggregated, integrated and disintegrated, forming different types of shapes or constellations in said system, also called a complex20. A quale (singular for qualia), would be the
conceptual structure21 specified by a complex (for example, of neurons), in a particular state that is
intrinsically maximally irreducible (for a profound explanation see Oizumi et al., 2014 and Tononi & Koch, 2015). A system is not always conscious, and even if it can increase in its state repertoire22of
information, it does not necessarily integrate it. However, when a system generates more information than what each of its individual parts do, information has been integrated forming an experience or complex, i.e., qualia. In brief, consciousness has information regarding its experience and those experiences are graded according to the amount of information integrated. Thus, consciousness is (i), gradual (ii), intrinsic to reality and (ii), potentially everywhere (not limited to animals)23. Not all
organizations of systems have experiences, since information needs to be sufficiently integrated, and not merely aggregated, in large repertoires in order to do so.
This is a thought provoking approach which deserves its own paper to explain, but it is worth mentioning since, under its assumptions, it is possible to explain why subjectivity is intrinsic to consciousness. The ESub experienced in the ASCmp would come to be the most basic shape in which information is integrated by our brains, the most basic complex. The NS, then, could be hypothesized to be either a more structured complex of the system in our brains, or the experience of the regulation of the information states in our brains themselves24. Therefore, in brief, according to the quantity and
quality of the complexes, there are different levels of consciousness that are integrated differently, forming different shapes within the system’s mechanisms. Within our brains, multiple kinds of patterns that account for our multifaceted experience of consciousness are formed. It could be possible that those peak moments of self-transcendence are very powerful and unique due to the fact that, in them, information is temporarily disintegrated compared to more ordinary states. Information gets separated and the systems’ complexes mixed, so the experience or qualia remaining has higher
20 Complex defined as “a maximally irreducible conceptual structure”, that is, a system with a set of elements that cannot be divided into
smaller parts without losing information and which holds its own perspective; a “something-it-is-like-to-be” experience. It is also called
qualia-space (Oizumi et al., 2014).
21 Concepts are closely related to complexes and are defined as set of elements within a system that are “the constituents of conscious
experience”, as they determine the causal role of a mechanism within a complex (Oizumi et al., 2014)(Gallimore, 2015).
22 The number of states it can potentially occupy. This is different from the amount of information the system can generate. A large state
repertoire is necessary, but not sufficient, for a system to generate large amount of information, as it could increase in size only by noise (for example, by randomly activating elements in it), without it being useful in the generation of more information (Gallimore, 2015).
23 Technically speaking, IIT ascribes to panpsychism; the notion of consciousness being an intrinsic part or property of reality. Nevertheless,
it needs to be distinguished from idealists (such as Plato), which embrace panpsychism as well. While the former holds consciousness as an intrinsic part of the physical world, idealists hold the notion that there is no physical matter, but only consciousness taken as a different substance.
24 That is, the systems of the brain in its waking, adult, normal shapes tends to be an interaction of multiple complexes, and what we
experience as our NS is the regulation of such complexes and not a complex in itself. However, whenever the brain’s complexes are forced to switch their shape (by either meditation, psychedelics, or any other ASC like sleeping, anesthesia, etc.) then the experience of the NS gets dissolved momentarily, leaving only the ESub.
uncertainty (Gallimore, 2015; more on this in Chapter 3). Then, after the ASCmp, the transitory feature of consciousness makes it stabilize again into the normal patterns formed by our brain, returning to the experience of a NS.
This conceptualization of consciousness could even be argued to be compatible with the enactive and embodied cognition approaches; while the latter explain consciousness by saying that it emerges from the interaction between our brain-body and the environment, the former posits that consciousness is inherent to the fabric of the universe, which grants room for a future analysis on their arguments. Also, if brains have the capacity to form complex shapes of integrated information, while systems without such configuration remain unconscious/un-aware, it opens the debate to analyze exactly how conscious plants, objects, computers or the internet are25. Finally, as consciousness doesn’t emerge
from these systems as a new property of reality but it is already an intrinsic part of it, by ascribing consciousness to the physical plane the hard mind/body problem is resolved.
Conclusion of the Chapter
In this chapter, with a phenomenological approximation of altered states of consciousness induced by meditation and psychedelics I wanted to analyze the insights they bring towards our understanding of the self and consciousness and relate them to some of the modern philosophical theories of the mind. The most renowned experience is that of the dissolution of the self and the dichotomy between subject and object. These experiences agree with both the reductionist and non-reductionist stances by showing the NS is illusory, and further emphasize the importance of making a semantic difference in the non-reductionist approach of phenomenologists by defining the ES as an ESub. Furthermore, due to the epistemological and ontological character of the study of the self and consciousness, the hard problem of consciousness was considered and an initial attempt to link the findings with a framework that could solve this issue was given. I propose IIT to be a good candidate for this, due to its consideration of qualia as being an intrinsic part of the structure of reality, which is congruent with the experience of an ESub in ASCmp. This could be an idea worth developing in further writings. With all this, I hope to have made a brief analysis of the philosophy of mind debate around the notion of self and consciousness taking the evidence reported on ASCmp while arguing in favor of a phenomenological analysis as a valid tool for research in this topic. I also took the chance
to give a glimpse on how these conclusions can be linked with new scientific theories that may take us closer to a holistic comprehension of consciousness.
C
HAPTER2
Neural mechanisms of Meditation and Psychedelics
There are multiple techniques available for elucidating the neural mechanisms of the brain. For the purposes of this text, we are going to limit our search to neuroimaging techniques that map the regions and networks involved with the higher states of consciousness induced by meditation and psychedelics26.
Part 1: Neural Mechanisms of Meditation
Several neuroimaging studies have been made to bring light to the neural basis of meditation. Unfortunately, the methods used to collect and analyze the data have varied just as much as the multiple meditation techniques employed between studies. This brings some methodological concerns and can account for the multiple regions that have been found to be involved in meditative practices. Here I will expose a generalization of the regions involved in this state, based on a summary (see Table ) of the different imaging studies performed while the practitioner is engaged in a type of meditation.
Broadly speaking, the prefrontal cortex (PFC), the anterior cingulate gyrus (ACC) and thalamus show activation whereas the parietal cortex (PC) show deactivation. As a result, there seems to be a functional difference in the parietal lobe (Mohandas, 2008).
Of particular importance is to analyze the PFC activation. The PFC is functionally divided into ventro-medial (VM) and dorsolateral (DL) aspects. While the former is associated with social understanding of others, personality, and emotion; the latter shows hemispheric specialization and is involved in semantic memory retrieval (left), working memory, directed attention, and temporal integration (right; Dietrich, 2003; Li, Mai, & Liu, 2014; Vaitl, Birbaumer, Gruzelier, Jamieson, Kotchoubey, Kübler, Lehmann, Miltner, Ott, Pütz, Sammer, Strauch, Strehl, Wackermann, & Weiss,
26 EEG and other electrical methodologies will not be listed in full, but by one meta-analysis, due to their large number. A neurochemical
approach is also beyond the scope of this text; although neurotransmitters are certainly modulated by psychedelics and play a role in the alteration of consciousness, this by itself does not provide enough information without the study of the neural structures in which the synaptic changes occur (Dietrich, 2003). Therefore, we will focus on the latter.
2005). As seen on Table , numerous studies on meditation consistently show activation of the PFC, usually reported bilaterally, but larger on the right hemisphere, without giving a more precise location of the activity (e.g., Herzog et al., 1990; Jevning, Wallace, & Beidebach, 1992; Khushu, Telles, Kumaran, Naveen & Tripathi 2000).
At first, the activation of the PFC may seem contradictory with the phenomenological meditative experience, in which the amount of the narrative or stream of thoughts feels to decrease. A general activation of the PFC would seem to suggest “hyperfrontality”, that is, an increase of activation in the frontal cortex, which implies an increase of such self-related thoughts and narrative. This would also go against the hypofrontality hypothesis of the brain in ASC proposed by Dietrich, (2003), in which he expected a general decrease in activation in the PFC compared that seen in the normal adult waking brain.
Furthermore, a reduction in the PFC could suggest a deactivation of the default mode network (DMN), which has been shown to activate while mind-wandering (Mason et al., 2007; Weissman, Roberts, Visscher, & Woldorff, 2006). Specifically, the DMN is a network of many regions that are usually active at rest, when no other task is being performed and the mind starts to wander; The MPFC is one of its most important functional hubs, along with the posterior cingulate cortex (PCC), the bilateral inferior parietal lobes (IPL) and the temporo-parietal junction (TPJ). Therefore, the decrease in task-unrelated thought experienced during meditation would suggest that the brain activity related to the DMN would show a decrease too.
However, once we further analyze the parts of the PFC which are activated during meditation in more recent and detailed studies, we can see that the PFC activation found must be related to the DLPFC rather than the MPFC (e.g., Azari et al., 2001; A. Newberg et al., 2001; Ritskes, Ritskes-Hoitinga, Stodkilde-Jorgensen, Baerentsen, & Hartman, 2003). Meditative practices rely on sustained concentration and heightened awareness of either the breath, a mantra, an image or other kinds of internal or external events. Consequently, the activation of the DLPFC is to be expected, as it constitutes a part in the frontal attentional network. This reasoning is further corroborated by the consistent activation of the ACC during meditation (e.g., Baerentsen, Hartvig, Stødkilde-Jørgensen, & Mammen, 2001; Hölzel et al., 2007), another important region of the attentional network, usually linked with error monitoring and mobilization (Vaitl, Birbaumer, Gruzelier, Jamieson, Kotchoubey, Kübler, Lehmann, Miltner, Ott, Pütz, Sammer, Strauch, Strehl, Wackermann, & Weiss, 2005), and the anterior ACC has been linked with self-knowledge, person knowledge and mentalizing (Amodio & Frith, 2006). The ACC and DLPFC coupling seem to be a key mark of the attentional aspects of meditation (A. B. Newberg & Iversen, 2003). In short, since the task of many meditation practices is to maintain attention on an object and to redirect the attention to it when it has strayed, there is
