Classic psychedelic substances, such as lysergic acid diethylamide and the active compound in magic mushrooms, psilocybin, are being studied again in a renaissance of psychedelic research. Psychedelic substances have profound effects on perception, emotion, and cognition, as well as the capacity to induce mystical-type experiences and ego-dissolution. Recent clinical studies indicate that these substances have positive effects on patient populations and healthy participants, both acutely and long-term. Neuroimaging studies show that psychedelics alter neural integration, by the disintegration of normally stable resting state networks, and increasing network connectivity between normally anticorrelated networks. This thesis will review the phenomenological characteristics of the psychedelic-induced altered state of consciousness, the therapeutic potential of the psychedelic-induced altered state of consciousness, and neuroimaging studies on the psychedelic state. Two theoretical accounts are compared on the brain basis of psychedelic-induced altered state of consciousness. From the recent research on psychedelics a novel theory of conscious states has evolved, the entropic brain theory. This theory will be compared to the integrated information theory, a well-established theory of consciousness within cognitive neuroscience.

abstract: Panpsychist double aspect theory, the most promising version of panpsychism, holds that the mental and the physical are mutually irreducible properties, or features, of ultimate matter, therefore they both are ontologically fundamental and ubiquitous. This version of panpsychism involves the following two notions: anti-reductivism and anti- emergentism. The former states that mental phenomena are not recordable in terms of physics. The latter implies that mental phenomena do not causally arise only from a certain macroscale physical condition, and the mental and the physical do not constitute an ontological hierarchy. From these notions, it follows that any macroscale mental phenomenon is the result of a combination of ultimate mental properties. Yet this idea creates the combination problem: how higher level mentality, e.g., human or animal consciousness, arises from lower level mentality, the ultimate mental "particles." Panpsychist double aspect theory purports to find the proper location of mind in the world without being vulnerable to typical mind-body problems. Nevertheless, since this version of panpsychism explains the ontological structure of higher level mentality as analogous to the atomic structure of a molecular physical entity, the combination problem arises. In Chapter 1, I explain the general conception of panpsychism. Chapter 2 shows the plausibility of panpsychist double aspect theory and how the combination problem arises from this version. I discuss the history and implications of the combination problem in Chapter 3. In Chapter 4, I introduce some alternative versions of panpsychism that do not raise the combination problem, and point out their implausibility. The intelligibility of mental combination is explained in Chapter 5. The moral of these chapters is that our epistemic intuition that mind is not composed of "smaller" minds fails to undermine the possibility that mind is structurally complex. In Chapter 6, I argue that C. Koch and G. Tononi's integrated information theory (IIT) is a form of panpsychism, and that the IIT can serve as a model for solving the combination problem. However, I am not committed to the IIT, and I point out theoretical weaknesses of the IIT besides the combination problem. / Dissertation/Thesis / M.A. Philosophy 2013

This thesis evaluates the integrated information theory (IIT) by looking at how it may answer some central problems of consciousness that the author thinks any theory of consciousness should be able to explain. The problems concerned are the mind-body problem, the hard problem, the explanatory gap, the binding problem, and the problem of objectively detecting consciousness. The IIT is a computational theory of consciousness thought to explain the rise of consciousness. First the mongrel term consciousness is defined to give a clear idea of what is meant by consciousness in this thesis; followed by a presentation of the IIT, its origin, main ideas, and some implications of the theory. Thereafter the problems of consciousness will be presented, and the explanation the IIT gives will be investigated. In the discussion, some not perviously—in the thesis—discussed issues regarding the theory will be lifted. The author finds the IIT to hold explanations to each of the problems discussed. Whether the explanations are satisfying is questionable.