AN EVALUATION OF THE INTEGRATED INFORMATION THEORY AGAINST SOME CENTRAL PROBLEMS OF CONSCIOUSNESS

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.  integrated information theory, phenomenal consciousness, subjective experience, mind-body, the hard problem, binding, testing   AN EVALUATION OF THE IIT !4 Table of Content Introduction 5 Defining Consciousness 6 Introduction to the Integrated Information Theory 8 Historical Background 8 The Approach 9 The Core of the IIT 9 Axioms 11 Postulates 13 The Conscious Mechanism of the IIT 15 Some Key Terms of the IIT 17 The Central Identity of the IIT 19 Some Implications of the IIT 20 Introduction to the Problems of Consciousness 25 The Mind-Body Problem 25 The Hard Problem 27 The Explanatory Gap 28 The Problem With the Problems Above 28 The Binding Problem 30 The Problem of Objectively Detecting Consciousness 31 Evaluation of the IIT Against the Problems of Consciousness 37 The Mind-Body Problem vs. the IIT 38 The Hard Problem vs. the IIT 40 The Explanatory Gap vs. the IIT 42 The Binding Problem vs. the IIT 43 The Problem of Objectively Detecting Consciousness 45  Intuitively we like to believe that things which act and behave similarly to ourselves are conscious, things that interact with us on our terms, mimic our facial and bodily expressions, and those that we feel empathy for. But what about things that are superficially different from us, such as other animals and insects, bacteria, groups of people, humanoid robots, the Internet, self-driving cars, smartphones, or grey boxes which show no signs of interaction with their environment? Is it possible that intuition and theory of mind (ToM) may be misleading; that one wrongly associate consciousness with intelligence, human-like behaviour, and ability to react on stimuli? Perhaps we attribute consciousness to things that are not conscious, and that we miss to attribute it to things that really have vivid experiences. To address this question, many theories have been proposed that aim at explaining the emergence of consciousness and to give us tools to identify wherever consciousness may occur. The integrated information theory (IIT) (Tononi, 2004), is one of them. It originates in the dynamic core theory (Tononi & Edelman, 1998) and claims that consciousness is the same as integrated information. While some theories of consciousness only attempt to explain consciousness in neurobiological systems, the IIT is assumed to apply to non-biological systems. Parthemore and Whitby (2014) raise the concern that one may be tempted to reduce consciousness to some quantity X, where X might be e.g. integrated information, neural oscillations (the 40 Hz theory, Crick & Koch, 1990), etc. A system that models one of those theories may prematurely be believed to be conscious argue Parthemore and Whitby (2014). This tendency has been noted among researchers of machine consciousness, of some who have claimed their systems to have achieved at least minimal consciousness (Gamez, 2008a). The aim of this thesis is to take a closer look at the IIT and see how it responds to some of the major problems of consciousness. The focus will be on the mechanisms which AN EVALUATION OF THE IIT !6 the IIT hypothesises gives rise to conscious experience (Oizumi, Albantakis, & Tononi, 2014a), and how it corresponds to those identified by cognitive neurosciences. This thesis begins by offering a working definition of consciousness; that gives a starting point for what we are dealing with. Then it continues with an introduction to the IIT, which is the main focus of this thesis. I have tried to describe the theory in my own words, where some of more complex details not necessary for my argument are left out. I have taken some liberties in adapting the terminology to fit better with what I find elsewhere in cognitive neurosciences and consciousness science avoiding distorting the theory. Thereafter follows the problems of consciousness, which a theory of consciousness, such as IIT, should be able to explain. The problems explored in this thesis are the mind-body problem, the hard problem, the explanatory gap, the binding problem and the problem of objectively detecting consciousness. Each problem is used to evaluate the theory by looking at what explanations the theory is providing. Defining Consciousness What is this thing that is called consciousness and what does it mean to be conscious? Science doesn’t seem to provide with one clear definition of consciousness (Cotterill, 2003; Gardelle & Kouider, 2009; Revonsuo, 2010). When lay people talk about consciousness and being conscious they commonly refer to being attentive and aware and having intentions (Malle, 2009). Both John Searle (1990) and Giulio Tononi (Tononi, 2008, 2012a; Oizumi et al., 2014a) refer to consciousness as the thing that disappears when falling into dreamless sleep, or otherwise become unconscious, and reappears when we wake up or begin to dream. The problem with defining the term consciousness is that it seems to point to many different kinds of phenomena (Block, 1995). In an attempt to point it out and pin it down, the AN EVALUATION OF THE IIT !7 usage of the term needs to be narrowed down to fit the intended purpose. Cognition and neuroscientists alike commonly use terms such as non-conscious, unconscious, awake state, lucid dreaming, etc. which all refer to the subjective experience, but of different degrees, levels, and states (Revonsuo, 2009). Commonly used in discussions regarding consciousness are also terms such as reflective consciousness, self-consciousness, access consciousness, and functional consciousness. Those terms have little to do with the subjective experience per se, at best they describe some of the content of an experience, but mostly refer to observed behaviour (Block, 1995). It seems that researchers of artificial machine consciousness often steer away from the subjective experience. Instead, they focus on the use, the functions, and the expressions of consciousness, as it may be perceived by a third person (Gamez, 2008a). In this thesis, the term consciousness is used for the phenomenon of subjective experience, per se. It is what e.g. differs the awake state from dreamless sleep. It is what differs one’s own conscious thought processes from a regular computer’s nonconscious information processing, or one’s mindful thought from unconscious sensory-motoric control and automatic responses. It is what is lost during anaesthesia and epileptic seizures. Without consciousness, there wouldn’t be “something it is like to be” (Nagel, 1974, p. 436) and there would be no one there to experience the world (Tononi, 2008). Without it we would not experience anything. We would not even regard ourselves to be alive. It is the felt raw experience, even before it is attended to, considered and possible to report, i.e. what Block (1995) refers to as phenomenal consciousness. This is also often the starting point of cognitive and neurological theories of consciousness, which try to explain how experience emerge within the brain by exploring the differences between conscious and nonconscious states and processes.  The integrated information theory originates in the collected ideas of Tononi, Sporns, and Edelman (1992, 1994). In their early collaborative work, they developed a reentering model of visual binding which considered cortico-cortical connections as the basis for integration (Tononi et al., 1992). Two years later they presented a measure hypothesised to describe the neural complexity of functional integration in the brain (Tononi et al., 1994). The ideas of the reentering model and neural complexity measure developed into the more known dynamic core hypothesis (DCH) of the neural substrate of consciousness (Tononi & Edelman, 1998). The thalamocortical pathways played the foundation of sensory modality integration. In the DCH, a measure of integration based on entropy was introduced, which later became Φ, the measurement of integrated information (Tononi & Sporns, 2003). This laid the foundation for the information integration theory of consciousness (Tononi, 2004). The IIT is under constant development and has since it first was presented undergone three major revisions. The latest, at the time of writing, is referred to as version 3.0 (Oizumi et al., 2014a), which this thesis mostly relies on. The basic philosophical and theoretical assumptions have been preserved throughout the development of the theory. Some of the terminology and mathematics have changed between the versions (Oizumi, Amari, Yanagawa, Fujii, & Tsuchiya, 2015). Axioms and p