Consciousness is a quality of the mind generally regarded to comprise qualities such as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and one's environment. It is a subject of much research in philosophy of mind, psychology, neuroscience, and cognitive science.

Representation of consciousness from the 17th century.

Some philosophers divide consciousness into phenomenal consciousness, which is experience itself, and access consciousness, which is the processing of the things in experience ^[1] Phenomenal consciousness is the state of being conscious, such as when we say "I am conscious." Access consciousness is being conscious of something in relation to abstract concepts, such as when we say "I am conscious of these words." Various forms of access consciousness include awareness, self-awareness, conscience, stream of consciousness, Husserl's phenomenology, and intentionality. The concept of phenomenal consciousness is closely related to the concept of qualia.

An understanding of necessary preconditions for consciousness in the human brain may allow us to address important ethical questions. For instance, to what extent are non-human animals conscious? At what point in fetal development does consciousness begin? Can machines achieve conscious states? ^[2] Are todays autonome and intelligent machines already conscious? These issues are of great interest to those concerned with the ethical treatment of other beings, be they animals, fetuses, or, in the future, machines. ^[3]

In common parlance, consciousness denotes being awake and responsive to one's environment; this contrasts with being asleep or being in a coma. The term 'level of consciousness' denotes how consciousness seems to vary during anesthesia and during various states of mind, such as day dreaming, lucid dreaming, imagining, etc. Nonconsciousness exists when consciousness is not present. There is speculation, mostly among religious groups, that consciousness may exist after death or before birth.

Etymology

"Consciousness" derives from Latin conscientia which primarily means moral conscience. In the literal sense, "conscientia" means knowledge-with, that is, shared knowledge. The word first appears in Latin juridic texts by writers such as Cicero. Here, conscientia is the knowledge that a witness has of the deed of someone else. In Christian theology, conscience stands for the moral conscience in which our actions and intentions are registered and which is only fully known to God. Medieval writers such as Thomas Aquinas describe the conscientia as the act by which we apply practical and moral knowledge to our own actions.^[4] René Descartes has been said to be the first philosopher to use "conscientia" in a way that does not seem to fit this traditional meaning, and, as a consequence, the translators of his writings in other languages like French and English coined new words in order to denote merely psychological consciousness. These are, for instance, conscience, and Bewusstsein.^[5] However, it has also been argued that John Locke was in fact the first one to use the modern meaning of consciousness in his Essay Concerning Human Understanding, although it remains closely intertwined with moral conscience (I may be held morally responsible only for the act of which I am conscious of having achieved; and my personal identity - my self - goes as far as my consciousness extends itself). The modern sense of "consciousness" was therefore first found not in Descartes' work - who sometimes used the word in a modern sense, but did not distinguish it as much as Locke would do -, but in Locke's text. The modern sense of the word (consciousness associated to the idea of personal identity, which is assured by the repeated consciousness of oneself) was therefore introduced by Locke; but the word "conscience" itself was coined by Pierre Costes, French translator of Locke. Henceforth, the modern sense first appeared in Locke's works, but the word itself first appeared in the French language.^[6]

Locke's influence upon the concept can be found in Samuel Johnson's celebrated Dictionary, in which Johnson abstains from offering a definition of "consciousness," choosing instead to simply quote Locke.

Philosophical approaches

There are many philosophical stances on consciousness, including: behaviorism, dualism, idealism, functionalism, phenomenalism, phenomenology and intentionality, physicalism, emergentism, mysticism, personal identity etc.

Phenomenal and access consciousness

Phenomenal consciousness (P-consciousness) is simply experience, it is moving, coloured forms, sounds, sensations, emotions and feelings with our bodies and responses at the center. These experiences, considered independently of any impact on behavior, are called qualia. The hard problem of consciousness was formulated by Chalmers in 1996, dealing with the issue of "how to explain a state of phenomenal consciousness in terms of its neurological basis" (Block 2004).

Access consciousness (A-consciousness) is the phenomenon whereby information in our minds is accessible for verbal report, reasoning, and the control of behavior. So, when we perceive, information about what we perceive is often access conscious; when we introspect, information about our thoughts is access conscious; when we remember, information about the past (e.g., something that we learned) is often access conscious; and so on. Chalmers thinks that access consciousness is less mysterious than phenomenal consciousness, so that it is held to pose one of the easy problems of consciousness. Dennett denies that there is a "hard problem", asserting that the totality of consciousness can be understood in terms of impact on behavior, as studied through heterophenomenology. There have been numerous approaches to the processes that act on conscious experience from instant to instant. Philosophers who have explored this problem include Gerald Edelman, Edmund Husserl and Daniel Dennett. Daniel Dennett (1988) suggests that what people think of as phenomenal consciousness, such as qualia, are judgements and consequent behaviour. He extends this analysis (Dennett, 1996) by arguing that phenomenal consciousness can be explained in terms of access consciousness, denying the existence of qualia, hence denying the existence of a "hard problem."

Events that occur in the mind or brain that are not within phenomenal or access consciousness are known as subconscious events.

The description and location of phenomenal consciousness

Although it is the conventional wisdom that consciousness cannot be defined, philosophers have been describing phenomenal consciousness for centuries. René Descartes wrote Meditations on First Philosophy in the seventeenth century, containing extensive descriptions of what it is to be conscious. Descartes described conscious experience as imaginings and perceptions laid out in space and time that are viewed from a point. Each thing appears as a result of some quality (qualia) such as colour, smell, etc. Other philosophers, such as Nicolas Malebranche, Thomas Reid, John Locke, David Hume and Immanuel Kant, also agreed with much of this description, although David Hume and Immanuel Kant avoid mentioning a place from which experience is viewed (see further reading below). The extension of things in time was considered in more detail by Kant and James. Kant wrote that "only on the presupposition of time can we represent to ourselves a number of things as existing at one and the same time (simultaneously) or at different times (successively)." William James stressed the extension of experience in time and said that time is "the short duration of which we are immediately and incessantly sensible." These philosophers also go on to describe dreams, thoughts, emotions, etc.

When we look around a room or have a dream, things are laid out in space and time and viewed as if from a point. However, when philosophers and scientists consider the location of the form and contents of this phenomenal consciousness, there are fierce disagreements. As an example, Descartes proposed that the contents are brain activity seen by a non-physical place without extension (the Res Cogitans), which, in Meditations on First Philosophy, he identified as the soul. This idea is known as Cartesian Dualism. Another example is found in the work of Thomas Reid who thought the contents of consciousness are the world itself, which becomes conscious experience in some way. This concept is a type of Direct realism. The precise physical substrate of conscious experience in the world, such as photons, quantum fields, etc. is usually not specified.

Other philosophers, such as George Berkeley, have proposed that the contents of consciousness are an aspect of minds and do not involve matter at all. This is a type of Idealism. Yet others, such as Leibniz, have considered that each point in the universe is endowed with conscious content. This is a form of Panpsychism. Panpsychism is the belief that all matter, including rocks for example, is sentient or conscious. The concept of the things in conscious experience being impressions in the brain is a type of representationalism, and representationalism is a form of indirect realism.

Some philosophers, such as David Armstrong and Daniel Dennett, believe that qualia exist in terms of judgements or beliefs about things in the world, and are therefore meaningless when separated from behavior, while other philosophers insist that qualia cannot be understood in terms of belief. Dennett believes that "ineffable, intrinsic, private" qualia do not exist (Dennett 1988). However, Dennett does not believe that we lack conscious, phenomenal experience.

"Dennett suggests that while some episodes of mental life have impoverished contents, others are very rich and are full of content and information. Block would characterize the rich episodes of mental life as being instances of P-Consciousness and in cases where Dennett would suggest that content is impoverished, Block would claim that P-Consciousness is missing altogether." (Silby, 1998) [1]

It is sometimes held that consciousness emerges from the complexity of brain processing. The general label 'emergence' applies to new phenomena that emerge from a physical basis without the connection between the two explicitly specified.

Some theorists hold that phenomenal consciousness poses an explanatory gap. Colin McGinn takes the New Mysterianism position that it can't be solved, and Chalmers criticizes purely physical accounts of mental experiences based on the idea that philosophical zombies are logically possible and supports property dualism. But others have proposed speculative scientific theories to explain the explanatory gap, such as Quantum mind, space-time theories of consciousness, and Electromagnetic theories of consciousness to explain the correspondence between brain activity and experience.

Parapsychologists sometimes use the unproven concepts of psychokinesis or telepathy to support the dualism belief that consciousness is not confined to the brain.

Philosophical criticisms of the concept of consciousness

From the eighteenth to twentieth centuries many philosophers concentrated on relations, processes and thought as the most important aspects of consciousness. These aspects would later become known as "access consciousness" and this focus on relations allowed philosophers such as Marx, Nietzsche and Foucault to claim that individual consciousness was dependent on such factors as social relations, political relations and ideology.

Locke's "forensic" notion of personal identity founded on an individual conscious subject would be criticized in the 19th century by Marx, Nietzsche and Freud following different angles. Martin Heidegger's concept of the Dasein ("Being-there") would also be an attempt to think beyond the conscious subject.

Marx considered that social relations ontologically preceded individual consciousness, and criticized the conception of a conscious subject as an ideological conception on which liberal political thought was founded. Marx in particular criticized the 1789 Declaration of the Rights of Man and of the Citizen, considering that the so-called individual natural rights were ideological fictions camouflaging social inequality in the attribution of those rights. Later, Louis Althusser would criticize the "bourgeois ideology of the subject" through the concept of interpellation ("Hey, you!").

Nietzsche, for his part, once wrote that "they give you free will only to later blame yourself", thus reversing the classical liberal conception of free will in a critical account of the genealogy of consciousness as the effect of guilt and ressentiment, which he described in On the Genealogy of Morals. Hence, Nietzsche was the first one to make the claim that the modern notion of consciousness was indebted to the modern system of penality, which judged a man according to his "responsibility", that is by the consciousness through which acts can be attributed to an individual subject: "I did this! this is me!". Consciousness is thus related by Nietzsche to the classic philosopheme of recognition which, according to him, defines knowledge.^[7]

According to Pierre Klossowski (1969), Nietzsche considered consciousness to be a hypostatization of the body, composed of multiple forces (the "Will to Power"). According to him, the subject was only a "grammatical fiction": we believed in the existence of an individual subject, and therefore of a specific author of each act, insofar as we speak. Therefore, the conscious subject is dependent on the existence of language, a claim which would be generalized by critical discourse analysis (see for example Judith Butler).

Michel Foucault's analysis of the creation of the individual subject through disciplines, in Discipline and Punish (1975), would extend Nietzsche's genealogy of consciousness and personal identity - i.e. individualism - to the change in the juridico-penal system: the emergence of penology and the disciplinization of the individual subject through the creation of a penal system which judged not the acts as it alleged to, but the personal identity of the wrong-doer. In other words, Foucault maintained that, by judging not the acts (the crime), but the person behind those acts (the criminal), the modern penal system was not only following the philosophical definition of consciousness, once again demonstrating the imbrications between ideas and social institutions ("material ideology" as Althusser would call it); it was by itself creating the individual person, categorizing and dividing the masses into a category of poor but honest and law-abiding citizens and another category of "professional criminals" or recidivists.

Consciousness and language

Because humans express their conscious states using language, it is tempting to equate language abilities and consciousness. There are, however, speechless humans (infants, feral children, aphasics, severe forms of autism), to whom consciousness is attributed despite language lost or not yet acquired. Moreover, the study of brain states of non-linguistic primates, in particular the macaques, has been used extensively by scientists and philosophers in their quest for the neural correlates of the contents of consciousness.

Julian Jaynes argued to the contrary, in The Origin of Consciousness in the Breakdown of the Bicameral Mind, that for consciousness to arise in a person, language needs to have reached a fairly high level of complexity. According to Jaynes human consciousness emerged as recently as 1300 BCE or thereabouts. Many philosophers, including W.V. Quine and Daniel Dennett, and neuroscientists, including Christof Koch, contest this hypothesis, as it suggests that prior to this "discovery" of consciousness, experience simply did not exist.^[8]

Cognitive neuroscience approaches

Modern investigations into and discoveries about consciousness are based on psychological statistical studies and case studies of consciousness states and the deficits caused by lesions, stroke, injury, or surgery that disrupt the normal functioning of human senses and cognition. These discoveries suggest that the mind is a complex structure derived from various localized functions that are bound together with a unitary awareness.

Several studies point to common mechanisms in different clinical conditions that lead to loss of consciousness. Persistent vegetative state (PVS) is a condition in which an individual loses the higher cerebral powers of the brain, but maintains sleep-wake cycles with full or partial autonomic functions. Studies comparing PVS with healthy, awake subjects consistently demonstrate an impaired connectivity between the deeper (brainstem and thalamic) and the upper (cortical) areas of the brain. In addition, it is agreed that the general brain activity in the cortex is lower in the PVS state. Some electroneurobiological interpretations of consciousness characterize this loss of consciousness as a loss of the ability to resolve time (similar to playing an old phonographic record at very slow or very rapid speed), along a continuum that starts with inattention, continues on sleep, and arrives to coma and death ^{[citation needed]}.

Loss of consciousness also occurs in other conditions, such as general (tonic-clonic) epileptic seizures, in general anaesthesia, maybe even in deep (slow-wave) sleep. At present, the best-supported hypotheses about such cases of loss of consciousness (or loss of time resolution) focus on the need for 1) a widespread cortical network, including particularly the frontal, parietal and temporal cortices, and 2) cooperation between the deep layers of the brain, especially the thalamus, and the upper layers, the cortex. Such hypotheses go under the common term "globalist theories" of consciousness, due to the claim for a widespread, global network necessary for consciousness to interact with non-mental reality in the first place.^{[citation needed]}

Brain chemistry affects human consciousness. Sleeping drugs (such as Midazolam = Dormicum) can bring the brain from the awake condition (conscious) to the sleep (unconscious). Wake-up drugs such as Anexate reverse this process. Many other drugs (such as alcohol, nicotine, Tetrahydrocannabinol (THC), heroin, cocaine, LSD, MDMA) have a consciousness-changing effect.

There is a neural link between the left and right hemispheres of the brain, known as the corpus callosum. This link is sometimes surgically severed to control severe seizures in epilepsy patients. This procedure was first performed by Roger Sperry in the 1960's. Tests of these patients have shown that, after the link is completely severed, the hemispheres are no longer able to communicate, leading to certain problems that usually arise only in test conditions. For example, while the left side of the brain can verbally describe what is going on in the right visual field, the right hemisphere is essentially mute, instead relying on its spatial abilities to interact with the world on the left visual field. Some say that it is as if two separate minds now share the same skull, but both still represent themselves as a single "I" to the outside world.^{[citation needed]}

The bilateral removal of the centromedian nucleus (part of the Intra-laminar nucleus of the Thalamus) appears to abolish consciousness, causing coma, PVS, severe mutism and other features that mimic brain death. The centromedian nucleus is also one of the principal sites of action of general anaesthetics and anti-psychotic drugs. This evidence suggests that a functioning thalamus is necessary, but not sufficient, for human consciousness.

Neurophysiological studies in awake, behaving monkeys performed by neuroscientists point to advanced cortical areas in prefrontal cortex and temporal lobes as carriers of neuronal correlates of consciousness. Christof Koch and Francis Crick argued that neuronal mechanisms of consciousness are intricately related to prefrontal cortex — the most advanced cortical area. Experimental work of Steven Wise, Mikhail Lebedev and their colleagues supports this view. They demonstrated that activity of prefrontal cortex neurons reflects illusory perceptions of movements of visual stimuli. Nikos Logothetis and colleagues made similar observations on visually responsive neurons in the temporal lobe. These neurons reflect the visual perception in the situation when conflicting visual images are presented to different eyes (i.e., bistable percepts during binocular rivalry). The studies of blindsight — vision without awareness after lesions to parts of the visual system such as the primary visual cortex — performed by Lawrence Weiskrantz and David P. Carey provided important insights on how conscious perception arises in the brain. In recent years the theory of two visual streams, vision for perception versus vision for action was developed by Melvyn Goodale, David Milner and others. According to this theory, visual perception arises as the result of processing of visual information by the ventral stream areas (located mostly in the temporal lobe), whereas the dorsal stream areas (located mostly in the parietal lobe) process visual information unconsciously. For example, quick catching of the ball would engage mostly the dorsal stream areas, and viewing a painting would be handled by the ventral stream. Overall, these studies show that conscious versus unconscious behaviors can be linked to specific brain areas and patterns of neuronal activation.^{[citation needed]}. However, neuroscience only focuses on the neural correlates of consciousness. The hard problem of consciousness is to explain how all these flows and electrochemical processes in the brain give rise to the inner experience of subjective awareness.

Physical approaches

Even at the dawn of Newtonian science, Leibniz and many others were suggesting physical theories of consciousness. Modern physical theories of consciousness can be divided into three types: theories to explain behaviour and access consciousness, theories to explain phenomenal consciousness and theories to explain the quantum mechanical (QM) Quantum mind. Theories that seek to explain behaviour are an everyday part of neuroscience, some of these theories of access consciousness, such as Edelman's theory, contentiously identify phenomenal consciousness with reflex events in the brain. Theories that seek to explain phenomenal consciousness directly, such as Space-time theories of consciousness and Electromagnetic theories of consciousness, have been available for almost a century, but have not yet been confirmed by experiment. Theories that attempt to explain the QM measurement problem include Pribram and Bohm's Holonomic brain theory, Hameroff and Penrose's Orch-OR theory, Spin-Mediated Consciousness Theory and the Many-minds interpretation. Some of these QM theories offer descriptions of phenomenal consciousness, as well as QM interpretations of access consciousness. None of the quantum mechanical theories has been confirmed by experiment, and there are philosophers who argue that QM has no bearing on consciousness.

There is also a concerted effort in the field of Artificial Intelligence to create digital computer programs that can simulate consciousness.

Free will and consciousness

Chris King in the article Chaos, Quantum-transactions and Consciousness (2003), starts from Einstein’s energy-momentum relation (retrocausality and supercausality), and states that all quantum objects are constantly faced with bifurcations which force the system to operate choices. King quotes Eccles, Penrose and Hameroff who proved the existence of quantum structures in living systems and arrives to the conclusion that life is moved not only by mechanical causes but also by final causes (attractors). According to King, a new and innovative description of the relation between mind and brain derives from this constant state of choice in which living structures are immersed. This constant state of choice would force living systems into a state of free will which would be common to all the levels and structures of life, from molecules to macrostructures, and organisms. This constant state of free will, would originate chaotic dynamics which organize in fractal structures. Starting from these premises King suggests two separate levels of explanation of consciousness. In the first level, information flows from the mind to the brain, through free will; in the second level, information flows from the brain to the mind, thanks to the selection and amplification of signals performed by fractal structures. King’s considers mind to be immaterial, and its organization would be the consequence of the cohesive properties of –E (syntropy). King suggests that, in order to understand what consciousness really is, it is necessary to start from free will, because at this level it becomes necessary to definitely refuse any attempt to use mechanical approaches (http://www.sintropia.it/english/2006-eng-3.htm).

Spiritual approaches

Spiritual approaches to consciousness involve the idea of altered states of consciousness or religious experience. Changes in the state of consciousness or a religious experience can occur spontaneously or as a result of religious observance. It is also maintained by some religions and religious factions that the universe itself is consciousness.

In shamanic practices, changes in states of consciousness are induced by activities that create trance states, such as drumming, dancing, fasting, sensory deprivation, exposure to extremes of temperature, or the use of psychoactive drugs. The experience that occurs is interpreted as entering a real, but parallel, world. In many polytheistic religions a change in emotional state is often attributed to the action of a god, for instance love was ruled by Aphrodite and Eros in Ancient Greek polytheism. In Hinduism the change in state is induced by the practice of yoga. Yoga means "union" and is intended to produce a state of oneness between the practitioner and the divine. In Islam and Christianity, the change of state can occur as a result of prayer or as a religious experience.

The change in state of consciousness in Hinduism, Buddhism, Christianity and Islam is reported to be quite similar. The pursuit of yoga and the Buddhist Jhanas involve feelings of oneness with the world that give rise to a state of rapture. This is also reported by those undergoing some forms of Christian (or Islamic) religious experience; for instance, James (1902) provides the following report:

I cannot express it in any other way than to say that I did "lie down in the stream of life and let it flow over me." I gave up all fear of any impending disease; I was perfectly willing and obedient. There was no intellectual effort, or train of thought. My dominant idea was: "Behold the handmaid of the Lord: be it unto me even as thou wilt," and a perfect confidence that all would be well, that all was well. The creative life was flowing into me every instant, and I felt myself allied with the Infinite, in harmony, and full of the peace that passeth understanding. There was no place in my mind for a jarring body. I had no consciousness of time or space or persons, but only of love and happiness and faith.

Gangaji, in her book, the Diamond in your Pocket (p68), puts it this way 'Consciousness is not an object. It is hereness itself. Our minds are usually involved with an object that appears and disappears in the hereness, and because of that, we overlook the nature of hereness. Pure consciousness is what these words appear in, what this book appears in, what all bodies appear in. It infuses all words and bodies, and it is conscious of itself, and it is you. In your recognition of yourself as pure consciousness, you awaken to yourself. Normally, when we speak of consciousness, we are referring to particular states of awareness - being aware of something or not being aware of something - rather than the awareness itself.'

Meditation is used in some forms of yoga such as Raja Yoga, Hatha Yoga, Transcendental meditation, the Buddhist Jhanas, the Buddhist Immaterial Jhanas (there are several versions of the jhanas in different types of Buddhism), in the practices of Christian monks and Islamic scholars such as Sufis. Meditation can have a calming influence on practitioners, as well as changing the state of consciousness. Theravada Buddhism views the Jhanas in a similar way that some yogic practices view the early stages of meditation - as a preliminary, in which it is demonstrated that states such as rapture are delusions (see The Jhanas in Theravada Buddhist Meditation: "With the fading away of rapture, he dwells in equanimity, mindful and discerning"). In most types of Buddhism, serenity meditation is followed by a philosophical "insight meditation" that focuses on the idea that the universe is consciousness only, one that is perhaps indistinguishable from Monism.

Functions of consciousness

We generally agree that our fellow human beings are conscious, and that much simpler life forms, such as bacteria, are not. Many of us attribute consciousness to higher-order animals such as dolphins and primates; academic research is investigating the extent to which animals are conscious. This suggests the hypothesis that consciousness has co-evolved with life, which would require it to have some sort of added value, especially survival value. People have therefore looked for specific functions and benefits of consciousness. Bernard Baars (1997), for instance, states that "consciousness is a supremely functional adaptation" and suggests a variety of functions in which consciousness plays an important, if not essential, role: prioritization of alternatives, problem solving, decision making, brain processes recruiting, action control, error detection, planning, learning, adaptation, context creation, and access to information.^{[citation needed]} Antonio Damasio (1999) regards consciousness as part of an organism's survival kit, allowing planned rather than instinctual responses.^{[citation needed]} He also points out that awareness of self allows a concern for one's own survival, which increases the drive to survive, although how far consciousness is involved in behaviour is an actively debated issue. Many psychologists, such as radical behaviorists, and many philosophers, such as those that support Ryle's approach, would maintain that behavior can be explained by non-conscious processes akin to artificial intelligence, and might consider consciousness to be epiphenomenal or only weakly related to function.

Regarding the primary function of conscious processing, a recurring idea in recent theories is that phenomenal states somehow integrate neural activities and information-processing that would otherwise be independent (see review in Baars, 2002). This has been called the integration consensus. However, it has remained unspecified which kinds of information are integrated in a conscious manner and which kinds can be integrated without consciousness. Obviously not all kinds of information are capable of being disseminated consciously (e.g., neural activity related to vegetative functions, reflexes, unconscious motor programs, low-level perceptual analyses, etc.) and many kinds can be disseminated and combined with other kinds without consciousness, as in intersensory interactions such as the ventriloquism effect.

A new theoretical framework, Supramodular Interaction Theory (SIT; Morsella, 2005, Psychological Review) is unique in that it identifies the primary, essential function of conscious processing by contrasting the task demands of consciously penetrable processes (e.g., pain, conflicting urges, and the delay of gratification) and consciously impenetrable processes (e.g., intersensory conflicts, peristalsis, and the pupillary reflex). With this contrastive approach, SIT builds upon the integration consensus by specifying which kinds of interaction require conscious processing and which kinds do not (e.g., some intersensory processes). SIT proposes that conscious processes are required to integrate high-level systems in the brain that are vying for (specifically) skeletomotor control, as described by the principle of parallel responses into skeletal muscle (PRISM). Accordingly, regarding processes such as digestion and excretion, one is conscious of only those phases of the processes that require coordination with skeletomotor plans (e.g., chewing or micturating) and none of those that do not (e.g., peristalsis). From this standpoint, consciousness functions above the level of the traditional module to “cross-talk” among high-level, specialized and often multi-modal, systems.

These abilities, especially social and cultural development needs extended ability for imaginations (manipulations on mental images) [2]

Ervin Laszlo argues that self-awareness, the ability to make observations of oneself, evolved. Emile Durkheim formulated the concept of so called collective consciousness, which is essential for organization of human, social relations. The accelerating drive of human race to explorations, cognition, understanding and technological progress[3] can be explained by some features of collective consciousness (collective self - concepts) and collective intelligence

Tests of consciousness

As there is no clear definition of consciousness and no empirical measure exists to test for its presence, it has been argued that due to the nature of the problem of consciousness, empirical tests are intrinsically impossible. However, several tests have been developed which attempt to provide an operational definition of consciousness and try to determine whether computers and other non-human animals can demonstrate through their behavior, by passing these tests, that they are conscious.

Turing Test

Alan Turing proposed what is now known as the Turing test to determine if a computer could be considered conscious. This test is commonly cited in discussion of artificial intelligence. The essence of the test is based on "the Imitation Game", in which a human experimenter attempts to converse, via computer keyboards, with two others. One of the others is a human (who, it is assumed is conscious) while the other is a computer. Because all of the conversation is via keyboards (teletypes, in Turing's original conception) no cues such as voice, prosody, or appearance will be available to indicate which is the human and which is the computer. If the human is unable to determine which of the conversants is human, and which is a computer, the computer is said to have "passed" the Turing test for consciousness.

The Turing test has generated a great deal of research and philosophical debate. For example, Daniel Dennett and Douglas Hofstadter argue that anything capable of passing the Turing test is necessarily conscious^[9], while David Chalmers, argues that a philosophical zombie could pass the test, yet fail to be conscious.^[10] Still others take it for granted that computers can think, since this is what they were designed to do.

It has been argued that the question itself is excessively anthropomorphic. Edsger Dijkstra commented that "The question of whether a computer can think is no more interesting than the question of whether a submarine can swim." Expressing the view that different words are appropriate for the workings of a machine to those of animals even if they produce similar results, just as submarines are not normally said to swim.

Philosopher John Searle developed a thought experiment, the Chinese room argument, which is intended to show problems with the Turing Test.^[11] Searle asks the reader to imagine a non-Chinese speaker in a room in which there are stored a very large number of Chinese symbols and rule books. Questions are passed to the person in the form of written Chinese symbols via a slot, and the person responds by looking up the symbols and the correct replies in the rule books. Based on the purely input-output operations, the "Chinese room" gives the appearance of understanding Chinese. However, the person in the room understands no Chinese at all. This argument has been the subject of intense philosophical debate since it was introduced in 1980, even leading to edited volumes on this topic alone.

The application of the Turing test to human consciousness has even lead to an annual competition, the Loebner Prize with "Grand Prize of $100,000 and a Gold Medal for the first computer whose responses were indistinguishable from a human's." For a summary of research on the Turing Test, see here.

Mirror test

See also the concept of the Mirror stage by Jacques Lacan

With the mirror test, devised by Gordon Gallup in the 1970s, one is interested in whether animals are able to recognize themselves in a mirror. The classic example of the test involves placing a spot of coloring on the skin or fur near the indiviual's forehead and seeing if they attempt to remove it or at least touch the spot, thus indicating that they recognize that the individual they are seeing in the mirror is themselves. Humans (older than 18 months), great apes (except for gorillas), bottlenose dolphins, and elephants [4] have all been observed to pass this test.

Delay test

One problem researchers face is distinguishing nonconscious reflexes and instinctual responses from conscious responses. Neuroscientists Francis Crick and Christof Koch have proposed that by placing a delay between stimulus and execution of action, one may determine the extent of involvement of consciousness in an action of a biological organism.

For example, when psychologists Larry Squire and Robert Clark combined a tone of a specific pitch with a puff of air to the eye, test subjects came to blink their eyes in anticipation of the puff of air when the appropriate tone was played. When the puff of air followed a half of a second later, no such conditioning occurred. When subjects were asked about the experiment, only those who were asked to pay attention could consciously distinguish which tone preceded the puff of air.

Ability to delay the response to an action implies that the information must be stored in short-term memory, which is conjectured to be a closely associated prerequisite for consciousness. However, this test is only valid for biological organisms. While it is simple to create a computer program that passes, such success does not suggest anything beyond a clever programmer.^[8]

References

^ Ned Block: On a Confusion about a Function of Consciousness" in: The Behavioral and Brain Sciences, 1995.
^ Stuart Shieber (ed): The Turing test : verbal behavior as the hallmark of intelligence, Cambrigde, Mass, MIT Press, 2004, ISBN 978-0-262-69293-9
^ Steven Marcus: Neuroethics: mapping the field. Dana Press, New York 2002. ISBN 978-0-9723830-0-4 .
^ See Aquinas, De Veritate 17,1 c.a.
^ See Catherine G. Davies, Conscience as Consciousness, Oxford 1990, and Hennig, Cartesian Conscientia.
^ See Etienne Balibar, Identité et différence. Le chapitre II, xxvii de l'Essay concerning Human Understanding de Locke. L'invention de la conscience. Paris: Editions du Seuil, 1998. ISBN 978-2-02-026300-9
^ See Friedrich Nietzsche, The Gay Science, §355.
^ ^a ^b Christof Koch, The Quest for Consciousness: A Neurobiological Approach. Englewood, Colorado: Roberts and Company Publishers.
^ Dennett, D.C. and Hofstadter, D. (1985). The Mind's I: Fantasies and reflections on self and soul (ISBN 978-0-553-34584-1)
^ Chalmers, D. (1997) The Conscious Mind: In Search of a Fundamental Theory. Oxford University Press. ISBN 0-19-511789
^ Searle, J. (1980) "Minds, Brains and Programs" Behavioral and Brain Sciences 3, 417-424.

Other disciplines

Psyche (psychology)

External links

Academic journals & newsletters

ASSC e-print archive containing articles, book chapters, theses, conference presentations by members of the ASSC.

Philosophy resources

Publications of the Tufts Center for Cognitive Studies, including Daniel Dennett
David Chalmers' directory of online papers on consciousness
Intuitions about Consciousness: Experimental Studies an article describing the folk intuitions about what is a conscious agent
Stanford Encyclopedia of Philosophy:
Internet Encyclopedia of Philosophy:
- Consciousness
- Higher-Order Theories of Consciousness

Miscellaneous sites

History of Consciousness Graduate Program, ("consciousness as forms of human expression and social action manifested in historical, cultural, and political contexts") at the University of California, Santa Cruz, headed by Dr. Angela Davis
Online lecture videos, from an undergraduate course taught by Christof Koch at Caltech on the neurobiological basis of consciousness in 2004.
Ken Wilber's Integral Theory of Consciousness from Journal of Consciousness Studies
Brain Atlas, Brain Maps, Neuroinformatics
Physics and Consciousness Quantum Relations to The Mind
Online course in consciousness at University of Virginia
A survey course at University of Florida
Edinburgh thesis (.ps) on consciousness including up-to-date reviews
Conscious Entities Discussions of leading theories and issues.
FAQ & Articles Consciousness & psi phenomena
Consciousness-Related Engineering Anomaly Princeton
Evolution of Consciousness Literature Review, Notes and Excerpts (.pdf) by Doug Phillips
Computational Models of the Attentional Blink
Experience, awareness and consciousness: suggestions for definitions as offered by an evolutionary approach
The role of consciousness in the evolution of human society

[Bl-1] Ned Block: On a Confusion about a Function of Consciousness" in: The Behavioral and Brain Sciences, 1995.

[tu-2] Stuart Shieber (ed): The Turing test : verbal behavior as the hallmark of intelligence, Cambrigde, Mass, MIT Press, 2004, ISBN 978-0-262-69293-9

[3] Steven Marcus: Neuroethics: mapping the field. Dana Press, New York 2002. ISBN 978-0-9723830-0-4 .

[4] See Aquinas, De Veritate 17,1 c.a.

[5] See Catherine G. Davies, Conscience as Consciousness, Oxford 1990, and Hennig, Cartesian Conscientia.

[6] See Etienne Balibar, Identité et différence. Le chapitre II, xxvii de l'Essay concerning Human Understanding de Locke. L'invention de la conscience. Paris: Editions du Seuil, 1998. ISBN 978-2-02-026300-9

[7] See Friedrich Nietzsche, The Gay Science, §355.

[Koch-8] Christof Koch, The Quest for Consciousness: A Neurobiological Approach. Englewood, Colorado: Roberts and Company Publishers.

[9] Dennett, D.C. and Hofstadter, D. (1985). The Mind's I: Fantasies and reflections on self and soul (ISBN 978-0-553-34584-1)

[10] Chalmers, D. (1997) The Conscious Mind: In Search of a Fundamental Theory. Oxford University Press. ISBN 0-19-511789

[11] Searle, J. (1980) "Minds, Brains and Programs" Behavioral and Brain Sciences 3, 417-424.

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Consciousness