The ALIUS Research Group was created to study all aspects of consciousness, with a specific focus on unusual or understudied conscious states traditionally classified as Altered States of Consciousness (ASCs). It fosters a unique interdisciplinary collaboration of researchers, involving inter alia computer scientists, biologists, neuroscientists, psychologists, philosophers, psychiatrists and anthropologists, towards the development of a systematic and scientific model of ASCs supported by both theoretical work and experimental studies.
The Scientific Study of Consciousness
For a long time, consciousness was not considered a serious scientific topic. Indeed, its subjective nature was deemed incompatible with objective methods of investigation – a claim partly motivated by the widespread endorsement of radical behaviorism in both psychology and philosophy during the first half of the 20th century (e.g. Ryle 1949; Skinner 1953; Quine 1960).
Fortunately, in recent decades, this prejudice has been gradually replaced by the belief that consciousness can be studied in a rigorous and scientific manner (e.g. Jackendoff 1987; Baars 2003; Marti et al. 2010). Several research programs bringing together neuroscientists, biologists, computer scientists, psychologists, psychiatrists and philosophers are currently investigating the nature of consciousness, and significant progress has been made in that domain.
However, most of these endeavors are limited in scope by their focus on a small sample of conscious states. Indeed, experimental studies usually investigate ‘standard’ states of consciousness with Western participants. Admittedly, certain ‘non-standard’ states such as dreaming, psychotic episodes and epilepsy have been paid some attention; yet these exceptions are sparse among a multitude of other ‘non-standard’ states which remain largely understudied, if not plainly ignored.
ALIUS Research Group aims at investigating consciousness in a scientific and systematic manner, claiming that the study of consciousness should not be solely confined to a specific subset of conscious states and human subjects. Understanding consciousness requires taking into account the great diversity of states humans can experience – accounting for multiple factors and variables such as age, culture, practices, mental health and pathologies. The study of consciousness thus requires charting the cartography of the multifarious types of conscious states experienced by humans across the globe and across the full spectrum of biological and cultural differences.
Redefining the Notion of “Altered State of Consciousness”
The set of non-standard conscious states usually left out of experimental studies is often referred to as “Altered States of Consciousness” (ASCs). Although this phrase is a relatively recent invention coined in the 1960s, many authors have studied the same topic under various appellations long before this period, both in the Western world (e.g. Maupertuis 1752; Moreau 1845; James 1902) and in the Indo-Tibetan tradition (see Dreyfus and Thompson 2007; Franco 2009; Thompson 2014). Mental states traditionally associated with this notion include, inter alia, dream states, hypnosis, trance-like or mystical-type experiences, meditative states, psychotic states, sensory deprivation and drug-induced states. However, defining the notion of ASC has proven very difficult, for three main reasons.
First, there are many competing criteria according to which one might want to say that a given mental state should count as an ‘alteration’ of normal consciousness. Second, the very notion of normal or baseline conscious states is not uncontroversial, for many conscious states involving very different subjective effects and underlying neurobiological processes are usually bundled in the category of normal (or non-altered) states. Third, even if one is considering a single criterion of alteration with respect to a well-defined type of normality, it seems dubious that a clear-cut line could be drawn between normal and altered states. Therefore, defining the notion of ASCs in a satisfactory manner appears to require laying out both modes and degrees of alteration.
In a theoretical model of ASCs, both of these factors can be accounted for in terms of dimensions: a given model will define alterations of consciousness alongside one or several dimensions, which can be specified in physiological, neurocognitive or phenomenological terms, depending on the favored perspective on ASCs. If an alteration of consciousness is measured by means of dimensional variability, it can probably admit several degrees. In turn, different kinds of alterations of consciousness corresponding to distinct dimensions – or to significantly diverging degrees of the same dimension – can yield different types of ASCs. Of course, some types of ASC compatible with a given theoretical model can be ruled out by further empirical work, since there might be concrete limits to the extent to which mental states (or their underlying neurobiological processes) can be altered alongside a certain dimension.
Uni-Dimensional Models of Consciousness
The contemporary literature on ASCs features one-dimensional, two-dimensional and multidimensional accounts. One-dimensional models measure the alteration of consciousness alongside a single dimension, which in turn defines a universal distinction between normal and altered states. According to such models, all ASCs belong to the same type, which can be interpreted as entailing that ASCs form a natural kind. Such is the model originally put forward by Arnold Ludwig, who coined the term himself (Ludwig 1966). However, Ludwig’s own definition is quite vague; according to him, the single criterion used to identify ASCs should be a ‘deviation’ from the norm, be it of a physiological, psychological or pharmacological nature.
One might say that Ludwig’s one-dimensional model is disjunctive: he believes that a broad disjunction of deviations from normal states constitute a single broad dimension by means of which one can judge if a given state is altered or not. Within this model, the way in which mental states deviate from the norm is not meaningful at all – the single fact that there is a deviation from the norm (however construed) is sufficient to qualify a conscious state as altered. Accordingly, dreaming, meditation, hypnosis or psychedelic experiences, for instance, should all be understood as the same kind of conscious states. For this reason, one-dimensional models of ASCs are deeply problematic. Indeed, they bring together widely different states which do not necessarily have much in common – both in terms of etiology and phenomenology – and claim that they belong to the same type. Thus one-dimensional accounts do not seem to fulfill any explanatory or even significant descriptive role. The prominence of such accounts at the time when the expression ‘ASC’ was coined partly explains why the notion is rarely seen as a useful one in the scientific community, or even plainly rejected as a pseudo-scientific notion.
Bi- and Multi-Dimensional Models of Consciousness
However, there are more sophisticated models in recent literature. For instance, Roland Fischer’s two-dimensional account distinguishes ASCs from normal states with respect to two dimensions, namely sympathetic and parasympathetic activation of the autonomic nervous system (Fischer 1975; Fischer 1992). According to his experimental data, this model yields two types of ASCs, which he calls respectively the ergotropic type characterized by sympathetic hyperactivation (such as mystical trance and psychotic episodes in schizophrenia) and the trophotropic type characterized by parasympathetic hypoactivation (such as zazen and samadhi meditation).
Likewise, Philip Corlett and colleagues have developed a Bayesian model of ASCs with two dimensions: on the one hand high-level constraints which allow the making of predictions, and on the other hand low-level sensory inputs relaying error-signals towards higher levels (Corlett, Frith, and Fletcher 2009). Each dimension allows three different values (augmentation, stabilization or diminution), yielding nine possible types of ASCs.
Finally, there are models of ASCs which feature more than two dimensions. For instance, Adolf Dittrich’s pioneering work on the so-called APZ and OAV self-report questionnaires distinguishes ASCs according to subjective scores on three main psychometric scales – Oceanic Boundlessness, Dread of Ego Dissolution and Visual Restructuration – measuring various etiology-independent alterations of conscious experience (Dittrich 1975; Dittrich 1996; Dittrich 1998). Erich Studerus and colleagues later revised this model to include no less than eleven dimensions alongside which ASCs can be measured and distinguished (Studerus, Gamma, and Vollenweider 2010). Another researcher, Allan Hobson, has recently built on his work on dreams to develop a three-dimensional model of ASCs (Hobson, Pace-Schott, and Stickgold 2000; Hobson 2002; Hobson 2009), within which he studied differences between various sleeping states but also minimally conscious states (such as coma) and drug-induced states. All these multidimensional models converge in trying to account for the rich and multifaceted nature of ASCs in a scientific manner, instead of making an uncritical use of the notion.
The Scope of ALIUS
ALIUS Research Group was created to study all aspects of consciousness, with a specific focus on unusual or understudied conscious states traditionally classified as ASCs. It fosters a unique interdisciplinary collaboration of researchers, involving inter alia computer scientists, biologists, neuroscientists, psychologists, philosophers, psychiatrists and anthropologists, towards the development of a systematic and scientific model of ASCs supported by both theoretical work and experimental studies. While existing multidimensional models of ASCs offer interesting insights, none of them is exhaustive or uncontroversial. In particular, a complete typology of ASCs should be multi-layered, taking into account etiology (how are the various types of ASCs induced?), physiology (what neurophysiological processes underlie the various types of ASCs?) and phenomenology (what are the structural features of the subjective experience of various types of ASCs?).
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