The authors make common assumptions that I reject: that consciousness has functions distinct from those of the brain processes on which it depends, that there is a moment at which consciousness happens, and that consciousness itself can be measured. This leads to Cartesian materialism and asking such unanswerable questions as when and why consciousness evolved. An alternative view is proposed.
Altered states of consciousness (ASCs) are surprisingly hard to define and to measure. Neither ‘subjective’ methods (like verbal reports) nor ‘objective’ measures (such as how the state is induced, or physiological and behavioural criteria) are entirely satisfactory. Attempts to map ASCs are reviewed, including two- or three-dimensional maps such as Tart&s;s and Laureys’, and Hobson&s;s AIM...
After briefly surveying the basics of waking, sleeping, and dreaming, this chapter turns from physiology to experience. Dreams are often bizarre, with incongruity, uncertainty, and sudden scene changes, possibly due to failed feature binding. Studies of dream recall and content reveal sex differences in content and show how children&s;s dreams develop along with their cognitive abilities. Dream...
Two experiments involving an international collaboration of experimenters sought to replicate and extend a previously published psi experiment on precognition by Daryl Bem that has been the focus of extensive research. The experiment reverses the usual cause–effect sequence of a standard psychology experiment using priming and reaction times. The preregistered confirmatory hypothesis is that...
We may have powerful intuitions about our own minds, but they must be questioned. Could vision, consciousness, self, and free will all be illusory – meaning that they are not what they seem? This chapter concentrates on whether vision is a ‘grand illusion’. This idea emerged from research on ‘change blindness’, which found that even large changes in an image can go unnoticed if made when the...
Although there is no recognised definition of consciousness, many researchers refer back to the famous question, ‘What is it like to be a bat?’ If there is anything it is like for the bat, that is what is meant by being conscious. This is also called ‘phenomenal consciousness’ (P-consciousness) or ‘phenomenality’ and is sometimes contrasted with ‘access consciousness’ (A-consciousness)....
Could machines ever be conscious? Ways to find out include reverse-engineering human machines or artificial ones. A brief history of artificial intelligence (AI) leads from early automata through calculating machines and ‘Good Old-Fashioned AI’ to connectionism, embodied cognition, and swarm robotics. Turing asked ‘Can machines think?’ Attempts to pass his famous test are reviewed, including...
Introspection is essential to the study of subjective experience but is problematic. Some call for a special ‘first-person science’ of consciousness based on irreducible subjective facts; others claim that ‘first-person methods’ such as introspection, meditation, or other personal explorations and training are valid, but science is a collective enterprise and a science of consciousness is no...
Can the brain tell us everything we need to know about consciousness? Some materialists say yes, while theorists of ‘extended mind’ and ‘embodied cognition’ criticise ‘neurocentrism’ and say no. Mysterians claim that we can never understand consciousness at all. This chapter briefly reviews the anatomy and function of the human nervous system, from spinal cord to neocortex. In searching for the...
The problem of consciousness relates to what the world is made of, how it began, the nature of selves, and above all the mind–body problem. In philosophy, dualism is the idea that mind and matter are distinct – a common belief in most societies and religions. In Cartesian dualism (described by René Descartes), mind and matter are separate substances. Objections to this, and other forms of...
The metaphor of mind as a theatre is common and alluring, but might it lead us astray? Dennett criticises those who imagine a ‘Cartesian theatre’: a mythical place in which consciousness happens and its contents come and go. This cannot exist because the brain is a massively parallel system with no centre, place, or process where the ‘audience of one’ could be. Those who believe in it he calls...
Is the age-old distinction between the ‘conscious mind’ and ‘the unconscious’ valid, or do powerful, but false, intuitions mislead us? Unconscious, implicit, or subliminal perception is reviewed, from early ideas of a ‘subliminal self’ to modern debates over subliminal perception, including signal detection theory, priming, and the differences between objective/subjective and direct/indirect...
The Buddha claimed to have ‘woken up’, describing a way to end suffering by seeing all phenomena as impermanent and letting go of desire and the illusory self. Many others have described awakening, but do they all undergo the same changes in self and consciousness? Buddhism has interacted more closely with science and psychotherapy than other religions, perhaps because of its relative lack of...
Consciousness is ‘the last great mystery for science’. How can a physical brain create our experience of the world? What creates our identity? Do we really have free will? Could consciousness itself be an illusion? Exciting new developments in brain science are continuing these debates, and the field has now expanded to include biologists, neuroscientists, psychologists, and philosophers....
‘Altered states of consciousness’ discusses the states of consciousness during sleep, dreaming, hallucinations, out-of-body experiences, near-death experiences, meditation, and after taking psychoactive drugs. Psychologist Charles Tart defines an altered state of consciousness (ASC) as ‘a qualitative alteration in the overall pattern of mental functioning, such that the experiencer feels his...
What is consciousness? What does it do? Could we have evolved without it? ‘Why the mystery?’ considers the definition of consciousness and how psychologists, neuroscientists, and philosophers have tried to explain it. From the Cartesian dualism of René Descartes to the ‘hard problem’ of consciousness, a phrase coined in 1994 by the Australian philosopher David Chalmers, and the question ‘What...
‘The human brain’ considers the brain as a vast network of connections from which come our extraordinary abilities: perception, learning, memory, reasoning, language, and somehow or another—consciousness. Different areas deal with vision, hearing, speech, body image, motor control, and forward planning. They are all linked, but this is not done through one central processor, but by millions of...
‘The evolution of consciousness’ begins with two questions. First, which living creatures are conscious and in what way? Secondly, when and how did consciousness evolve? Consciousness could be an all-or-nothing phenomenon, with some creatures having it and others not. Or it might be a continuous variable, with some having more than others. Different theories of evolution of consciousness are...
Abstract: An implicitly dualist or Cartesian materialist theory of consciousness is proposed without citing the many well-known problems with such theories. A function for consciousness is proposed with no reference to the possibility that “consciousness itself” has no function of its own. The theory builds on proposed “subset consensus” and “integration consensus” when in the literature there...
‘Time and space’ discusses a range of experiments and theories of consciousness using examples such as neuroscientist Benjamin Libet's ‘half second lag’ and the ‘cutaneous rabbit’ test. Theories considered include dualism, quantum computing, ‘higher-order thought’, and psychologist Bernard Baars' global workspace theory. None of these theories can solve the basic mystery of subjective...
Reactions to claims of near-death experiences (NDE) range from the popular view that this must be evidence for life after death, to outright rejection of the experiences as, at best, drug induced hallucinations or, at worse, pure invention. Twenty years, and much research, later, it is clear that neither extreme is correct.