What is Consciousness?

Alfredo Pereira Jr. & Hans Ricke

What is Consciousness? Towards a Preliminary Definition Abstract: There is little or no general agreement about what researchers should focus on when studying consciousness. The most active scientific studies often use the methods of Cognitive Neuroscience and focus mainly on vision. Other aspects and contents of consciousness, namely thoughts and emotions, are much less studied, possibly leading to a biased view of what consciousness is and how it works. In this essay we describe what we call a referential nucleus, implicit in much of consciousness research. In this context, ‘consciousness’ refers to (partially) reportable content experienced by living individuals. We then discuss the philosophical concept of a phenomenal world and another contemporary view that conscious experience involves, besides integration of information in the brain, participation in action-perception cycles in a natural, social and cultural environment. These views imply a need to reconceptualize ‘qualia’as the conscious aspect of subjective experiences, thus stating properties of consciousness that pose serious challenges to an exclusive approach via Cognitive Neuroscience, because experimental settings oversimplify conscious experiences, narrowing them to fragments correlated with measured brain activity and behaviour. In conclusion we argue that a science of consciousness requires a broad interdisciplinary range of research, including qualitative methods from the Human Sciences.

Correspondence: Alfredo Pereira Jr., Adjunct Professor; São Paulo State University (UNESP) — 18618–000 — Botucatu-SP — Brasil. E-mail: [email protected] Hans Ricke, Physician, Medical Sociologist, Gestaltist; Zürich — Switzerland. E-mail: [email protected]

Journal of Consciousness Studies, 16, No. 5, 2009, pp. ??–??

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A. PEREIRA JR. & H. RICKE

Introduction In October of 2007, Alfredo Pereira Jr. was invited by Hans Ricke to join a group of researchers involved in discussion of the definition of ‘consciousness’. The discussion began at Hans’ site (http://brain. parlaris.com) and developed further in the forum ‘Brain Physiology, Cognition and Consciousness’ in Nature Network (http://network. nature.com/groups/bpcc/forum/topics/1585), with 800 contributions by January 2009. In this essay, we describe our own particular ‘take’ on these discussions, which were far too extensive to describe in detail. Any attempt at definition must necessarily include some properties and exclude others. Our basic assumption is that consciousness is a natural phenomenon. Some participants in the discussions attributed a supernatural dimension to consciousness, but this possibility is not taken into consideration here. As with other fundamental concepts in science and philosophy, the task of defining consciousness is not an easy one, but four sub-tasks in particular can be distinguished: a)

To collect the meanings of the term ‘consciousness’ in folk psychology; b) To identify referents of ‘consciousness’ in scientific practice (ones that may or may not match definitions of consciousness overtly expressed by scientists); c) To define ‘consciousness’ relative to well accepted scientific and/or philosophical theories; d) To discover brain and other natural mechanisms directly involved with conscious activity. Although all sub-tasks are closely connected, the main goals of this essay are to identify scientific referents of the term ‘consciousness’ (step ‘b’ above) and then to look at where they may need elaboration to fit background theories (step ‘c’). Our approach is pragmatic in the sense that it is primarily directed towards achieving useful preliminary definitions that may sharpen distinctions between conscious and non-conscious activities in human and other subjects. Putting the emphasis on scientific practice, we follow Hacking (1983) who proposed that good science requires not only representations (scientific theories), but also means of intervention (scientific practices).

WHAT IS CONSCIOUSNESS?

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A Critical View of the Field Terms relevant to a science of consciousness can be divided into those that reflect different meanings attributed to ‘consciousness’, revealing theoretical differences among researchers, and those that express concepts needed for the taxonomy of a science of consciousness. Andrew Brook (2008) has collected many different uses of the term consciousness that he found in the literature, some having a more philosophical focus, while others are attached to scientific theoretical notions. The terminology required involves words like awareness, attention, receptivity, experience, memory, etc. We expect most of these to remain of use in any future, more systematic approach. Consciousness can be studied using different sorting paradigms. One would be to approach it from the side of Medicine (including Physiology and Psychiatry) and Psychology (in both cases, centering on human consciousness), building on well known and well established structures of these fields. A different approach would be to follow the development of consciousness ontogenetically, from foetal stages onwards. Another is to trace the possible evolutionary history of consciousness. Building on philosophical theories, we may develop general concepts of what consciousness essentially is and thus address approaches such as Panpsychism and Emergentism. We also can address social forms of consciousness, how they develop over time and within groups of human beings. Definitions of consciousness of course vary according to the theoretical and systematic frameworks within which they are used. Consciousness research these days happens mostly within Neuroscience, Computer Science, Philosophy and part of Psychology, namely Cognitive Psychology. Francis Crick may have been largely responsible for a special emphasis on visual perception, with influential statements like: ‘the problem of the neural basis of consciousness looks ever more tractable as neurobiologists delve into the process of visual perception’ (Crick, 1996). Other parts of science such as Clinical Psychology, Psychotherapy and Developmental Pediatrics seem to be less well integrated. However, narrowing consciousness down to visual consciousness may lead us astray because there are fundamental differences between the inner world and the outer world. The outer world provides stimuli that lead to a kind of linear process, the outcome of which is a more or less close fit between conscious perception and what exists out there in the visual environment. But the inner world also includes emotional and other mental dimensions, not always following linear pathways.

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Another major difference regarding inner experiences is that we have no way to compare them to objective (or inter-subjective) content, i.e. a public ‘stimulus’ as a visual object or scene. A third aspect is that there is competition between different sources of conscious content. Vision may sometimes provide the predominant content, but so may thoughts and emotions at other times. As conscious content is not necessarily fully reportable to third parties (see our discussion below), neuroscientific findings are difficult to link to specific parts of the content of consciousness at any given moment. Thus visual perception cannot serve as a general model of consciousness. Resolution of these issues will have to be left to further discussions. It is conceivable that clinical sciences such as Psychotherapy may provide clues to these questions, because methods are there available for bringing unconscious mental life into consciousness. A better integration of these separate fields might prove useful. In any case the focus of research needs to be widened to account for more difficult topics such as the conscious awareness of thoughts and emotions and how the different contents of consciousness are interrelated.

The Referential Nucleus of the Term ‘Consciousness’ in Scientific Practice While consciousness has traditionally been the concern of Philosophy and the Humanities, new methodologies have now been developed for the scientific study of consciousness, combining simultaneous execution of cognitive tasks, registers of brain activity and reports of conscious experiences by human subjects (see Frith et al., 1999). Several important results have been found about patterns of brain activity that correlate with conscious experiences. Seth et al. (2006) proposed a list of ‘features of consciousness that require theoretical explanation’ in the context of scientific investigation. Some of these features are about neural correlates: ‘consciousness is accompanied by … electrical brain activity (and) … is associated with activity within the thalamocortical complex; (and) … involves distributed cortical activity related to conscious contents’ (Seth et al., 2006). A second class of features concerns the structure of the phenomenon: conscious scenes are unitary … qualia are the discriminations entailed by the underlying neural activity; conscious scenes comprise a wide multimodal range of contents and involve multimodal sensory binding; (and)…have a focus/fringe structure; focal conscious contents are


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modulated by attention…scenes have an allocentric character. They show intentionality, yet are shaped by egocentric frameworks (Seth et al., 2006).

A third class of features encompass theoretical issues: consciousness is subjective and private and is often attributed to an experiencing ‘self’; conscious experience is reportable by humans, verbally and nonverbally; consciousness accompanies various forms of learning; consciousness is a necessary aspect of decision making and adaptive planning (Seth et al., 2006).

Do these features point to a concept of consciousness implicit in the way scientists approach the phenomenon? If so, what is the referent of the term ‘consciousness’ in this context? An answer to the above questions can be derived from analysis of common aspects of the empirical settings within which the phenomenon is approached. We call these common aspects the referential nucleus of the concept of consciousness in the context of scientific practice. First, scientific studies of consciousness use humans or other mammals as subjects. Registers of brain activity, mostly using encephalography or fMRI (leading to the results summarized in the above first class of features), are obtained in living individuals. Researchers thus implicitly assume that the living individual is the kind of system where consciousness can be found and studied. The same reasoning applies to the human sciences, e.g. Psychology, when personality traits are attributed to an individual, and Linguistics, when utterances of a speaker are described. Until a successful experiment demonstrates that an isolated part of a living system is conscious, or that a non-living system has consciousness, scientists ‘by default’ refer the property of being conscious to living individuals. Second, all kinds of conscious states/processes (sensation/perception; affect/emotion; decision/voluntary action and imagination/creative thinking) are assumed to have a content (related to the above second class of features). The conscious content of sensations, affective states and emotions can be conceived as being composed of patterns. Although it is difficult for anyone to describe these patterns in detail, their kinds are easily distinguishable by means of folk psychology terms like: pain, pleasure, thirst, fear, anger, happiness, etc. … In perceptual processes, the content is composed of perceived patterns (the ‘conscious scene’) inserted in egocentric spatial/temporal frames. In decision-making and voluntary action, the content is the action to be executed. In imagination and creative thinking, the content is composed of images and ideas (also in meditation practices, when the

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subject tries to avoid thinking, the sensation of nothingness can be regarded as a conscious content). Consciousness is always assumed to have content. In neuroscientific practice, first-person reports convey information about experienced content to the third-person perspective of scientific observers. Brain activity is registered and measured to identify correlates of the reported experiences. In Phenomenology, too, consciousness is conceptualized as an experience of something (the content), including experiences of inner states (e.g. sensation of hunger) and/or intentional objects, whether percepts or ‘imaginations’ of various types. Classical works on intentionality by Meinong, Brentano, Husserl and Frege, converge to the view that intentional objects are created or constructed by the subject, while Dretske (1973) alternatively suggested the possibility of law-like correspondence of mental patterns with external information patterns. A necessary condition for any science of consciousness is thus reportability — conscious content must be communicable to third parties like scientific observers. Usage of qualitative methods in the Human Sciences (as Psychology, History, Anthropology, Sociology) is based on the analysis of reported subjective content. Of course, this requirement does not mean that subjective contents are fully communicated to the observer. It does mean that all scientific experiments on consciousness require the experimental subject to report conscious content to the scientific observer, by one means or another. The requirement of reportability has two important restrictions. One is that it is a potential, not necessarily actual condition. A paralyzed conscious subject, for example, may not be able to actually report his/her contents at some particular moment but, provided they are conscious, report can potentially be made later (from memory) if recovery occurs. Another restriction is that reports are always partial and fallible. In experiments, the reliability of communication can be improved by simplifying relevant stimuli and other variables. With appropriate measures, reliable inter-subjective agreement is achievable. Summarizing the three common aspects, we conclude that in the current scientific context, ‘consciousness’ refers to reportable content experienced by living individuals. This is the identified referential nucleus of the term. Expanding this limited definition into a more comprehensive concept requires the consideration of well-accepted empirical results and theories.


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Beyond the Referential Nucleus In our quest for a definition of the term ‘consciousness’ in the scientific context, one limitation is that Cognitive Neuroscience focuses on a ‘lab-view’ of the phenomenon that often does not encompass the mental and emotional dynamics of people in socio-cultural contexts. Experimental settings oversimplify conscious experiences, narrowing them to fragments correlated with measured brain activity and behaviour. This is possibly due to the methodological bias present in the search for ‘Neural Correlates of Consciousness’ (NCC; see Crick and Koch, 1998; Chalmers, 2000). In the NCC paradigm, neuroscientists try to distinguish unconscious from conscious brain activity, while in other relevant scientific areas this distinction is not clear cut. In the context of Psychoanalysis, for instance, it is accepted that an unconscious content can be made conscious, and vice-versa. In Developmental Pediatrics, different degrees of consciousness are believed to occur during human life, e.g. self-consciousness emerging around the third year of life. In order to reach a broader concept of consciousness, it may be a good idea to look at how these and other human sciences have addressed the problems over the last century and more. The phenomenon of consciousness has a range of features, some of which are arguably necessary and others arguably sufficient. If we could rack up those that fulfill both conditions, we would be closer to an acceptable definition with a chance of contributing to a unification of the conceptual and methodological foundations of this science. The most difficult and most essential part of the puzzle is the basic mechanism of consciousness, which remains an enigma. However, some features of the mechanism are clear, e.g. it has limited capacity (Baars, 1988), it is unitary, and includes a dimension of ‘here and now’, but the big picture is still a matter of scientific (and, in many cases, metaphysical) speculation. In this section and in the next sections we expand the referential nucleus approach, beginning with a brief criticism of the preliminary definition of consciousness by Searle (2000): One often hears it said that ‘consciousness’ is frightfully hard to define. But if we are talking about a definition in common sense terms, sufficient to identify the target of the investigation, as opposed to a precise scientific definition of the sort that typically comes at the end of a scientific investigation, then the word does not seem to me hard to define. Here is the definition: Consciousness consists of inner, qualitative, subjective states and processes of sentience or awareness. Consciousness, so defined, begins when we wake in the morning from a dreamless sleep — and continues until we fall asleep again, die, go into a coma or

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A. PEREIRA JR. & H. RICKE otherwise become ‘unconscious’. It includes all of the enormous variety of the awareness that we think of as characteristic of our waking life. It includes everything from feeling a pain, to perceiving objects visually, to states of anxiety and depression, to working out cross word puzzles, playing chess, trying to remember your aunt’s phone number, arguing about politics, or to just wishing you were somewhere else.

Searle’s definition is insufficient to univocally characterize consciousness, since there are many unconscious ‘inner’ features, unconscious ‘qualitative’ states and unconscious ‘subjective’ states. ‘Sentience’ and ‘Awareness’ are parts of consciousness and also need definition. A conjunctive definition could be an improvement; for instance, ‘consciousness consists of inner and qualitative and subjective states’. In this formulation, being either inner or qualitative or subjective is not sufficient to be conscious. However, if a state has all these properties at the same time, then it would have more chance of being conscious. The second part of Searle’s text can be taken as an ostensive definition: ‘consciousness ... begins when we wake in the morning from a dreamless sleep — and continues until we fall asleep again, die, go into a coma or otherwise become unconscious’. Searle’s statement characterizes human living experience in general, without distinguishing conscious from unconscious experiences. As argued by Nixon (2007), among others, human experience can occur without consciousness. For instance, when we are sleeping without dreams we nevertheless have experiences without consciousness, e.g. the proprioceptive ones that prevent us falling out of our beds! Another good example of experience without consciousness is blindsight, a phenomenon in which people who are perceptually blind in a certain region of their visual field respond to visual stimuli without any associated qualitative experience (‘quale’). In addition to Searle’s proposal, we understand that conscious experience is a kind of experience with a distinctive status. This status is the result of the conjunction of several properties, which are not sufficient to characterize consciousness when considered separately. In conscious experience there is a content experienced by a subject, while in the case of unconscious phenomena there may be — among other possible combinations — a subject without content (e.g. animals under general anesthesia), and informational content without a subject (e.g. information patterns in the Hard Disk of a computer). More precisely, according to the referential nucleus above, an experience is conscious when there is a reportable content being experienced by a subject, such that the content is content for the subject.


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This reasoning also applies to recent discussion of artificial consciousness. If a robot has feedback mechanisms allowing the completion of action-perception cycles, then it can be considered as having experiences, but not conscious subjective experience, because of the lack of content and subjectivity. Naturally, if a sophisticated robot (still to be constructed) is endowed with the conjunction of all features considered to be necessary and sufficient for being conscious, one should be inclined to agree with those who eventually hold that he is conscious — or with the robot himself ...

Discussing the Phenomenal World In the philosophical tradition, consciousness is conceived as ‘phenomenal experience’ (as discussed by Chalmers, 1996) and conscious experience is described by the formula ‘what exists when there is something that it is like to be that thing’ (Nagel, 1974). How to relate both concepts with the referential nucleus above? What is meant by ‘phenomenal’ and what is meant by ‘experience’? In this section we discuss the idea of a phenomenal world, and how to translate it from a Kantian transcendental framework to the semantic framework of current scientific research on consciousness. In the next section we discuss the concept of experience. ‘Phainomenon’ in Greek means ‘that which appears’. ‘That which appears’ (the ‘phenomenon’ in English) appears to somebody (the conscious subject). Appearances involve, besides the content that appears to the subject, two fundamental dimensions: space and time. The idea of a phenomenal world was profoundly influenced by Kant’s transcendental philosophy, considering space and time as ‘a priori’ mental forms independent of previous experiences and placing the phenomenal world in a mental space/time distinct from the physical space/time where and when the individual as a biological system is located. In contrast, when scientists combine Psychophysical methods with the techniques of Cognitive Neuroscience, they refer to several dimensions of space and time. For the sake of simplicity, we classify only the spaces: a) the stimulus (‘physical’) space; b) the space where brain processes occur; c) the action space (the space where the subject can move her body and interact with the environment by means of tools and technologies); d) the conscious space (the ‘stage’ of the ‘theater’ of consciousness; see Baars, 1997), a ‘virtual’ space accessible by means of subjective reports; it is divided into ‘egocentric’ (perceived space centered on the subject) and ‘allocentric’ (perceived

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space projected to external coordinates). How to explain the phenomenal world in terms of such spaces and respective times? The problem of perceptual projection, posed by Velmans (1993), consists of explaining why conscious contents are not perceived as being located in the brain (where sensory signals are processed) but at other locations — such as in a tooth for toothache or in the whole room for sound broadcasted by home theaters. This kind of problem also occurs for time: cognitive brain activity occurs mostly at the millisecond scale, while usual conscious experiences occur mostly in the scale of several hundred milliseconds or more. He claims that ‘experiences are where we experience them to be. If the pain seems to be in the finger then that is where the pain is’ (Velmans, 1993). However, if the above reasoning is sound for pain — since the finger is part of our perceived body — it is probably not palatable for vision. How could our experience of the sun be located at the place where we see it (actually, millions of miles away from our perceived body)? More generally, how could subjective experiences be located outside of the body? One possible escape from this difficulty would be to assume Kantian Idealism from the start, conceptualizing space and time as mental forms. As a consequence, everything is considered as being located in the mind, which does not have a physical location. This solution seems to revert to another classical problem: the relation of Mind and Nature. Arnold Trehub adopts a Kantian perspective mixed with evolutionary considerations when proposing that ‘evolution has given humans (and possibly other creatures) the biological machinery to behave adaptively and thrive in a complex and uncertain world. The human brain must contain a biophysical counterpart to some kind of a 3D coordinate system with an Ego/Self location as its fixed origin within which the salient features of the world are first represented and then perceived so that we can either execute or plan effective action. … My claim is that before we can perceive and before we can act adaptively we must have a transparent phenomenal experience of the world from our own egocentric perspective’ (Trehub, 2008). The idea that we can have phenomenal experience ‘before’ perceiving and acting seems to be Kantian, but at the same time Trehub states that it is an evolutionary adaptation. Vakalopoulos (2005) and similar proposals are based on this kind of previous adaptive process (sometimes called ‘pre-adaptation’) that can be updated by means of interactions between different sensory and motor circuits. Our view of the phenomenal world is inspired by the contemporary concept of co-evolution. The living individual integrates sensory, cognitive and evaluative processes, using the results to coordinate adaptive


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action, and constantly receiving feedback about action outcomes. The completion of individual action-perception cycles allows neuromuscular circuits to shape their activity according to properties of the environment. In the long run, conscious space is shaped by properties of the space of interaction of the individual with the environment (the action space). Therefore, the phenomenal world is possibly constructed on the basis of co-evolution of interacting systems. Each individual’s perspective centers on a (relatively) large region defined by biological action effectors, and a whole range of associated emotional and cognitive evaluations; also — in the human case — technological products (glasses, hearing aids, computers …). These ideas are further developed in the following section.

Embodied and Embedded Conscious Experience Taking our referential nucleus as a starting point, the determination of a broader concept of conscious experience requires reframing the concept of ‘phenomenal experience’. Some ideas about the role of brain-body-environment interactions were raised in our public discussion, which may — or not — prove significant and suggestive of an emerging consensus. In this section we reflect on the contemporary view that conscious experience involves, besides brain activity and respective information patterns, also an interaction with the body and the environment: the ‘embodied and embedded’ view of cognition (see e.g. Varela et al., 1991; Clark, 1997; Clark and Chalmers, 1998). A picture of the formation of conscious content, in the context of Cognitive Neuroscience, can be summarized as follows. Several kinds of stimulation elicit distributed unconscious brain activity. Then an integration process (‘binding’) occur, resulting in the formation of scenes (Seth et al., 2006) or episodes (Pereira and Furlan, 2007) that reach the ‘conscious stage’ and becomes available for further processing (as proposed by Global Workspace Theory — see Baars, 1997; see also our discussion in http://network.nature.com/groups/bpcc/forum/ topics/1423). Conscious episodes therefore are integrated patterns that appear in consciousness during some given time, largely as the result of unconscious brain processes. Each episode is all-inclusive, containing all kinds of patterns — perceptual, imaginary, cognitive, mnemonic, affective, emotional, motor, etc. Brain patterns composing an episode are often claimed to be measurable in principle, in terms of information processing or whatever. However, some forum participants objected to this claim on the grounds that NCCs are never going to be fully equivalent to ‘mental’

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patterns. They argued that NCC descriptions are necessarily quantitative and cannot capture the ‘qualitative’ aspect of information (the ‘meaning’, as Freeman, 1995, and Nunn, 2007, called it). Meaning can only be defined by taking into consideration — among other factors — the actions to be executed by the body interacting with the environment. For this reason, perceptual patterns are extremely dynamical (the same rabbit smelling the same carrot never produces precisely the same pattern in its olfactory system, as Walter Freeman — see Freeman and Schneider, 1982 — has repeatedly shown). In a theoretical reconstruction of conscious experience, the formation of conscious episodes can be regarded as the initial stage. Conscious experience, in the ‘embodied and embedded’ view, can be described as a dynamical process that begins with the formation of an episode and continues with all possible kinds of affective, emotional, cognitive processing and coordination of action in the natural, social and cultural environment, generating a feedback on brain activity by means of perception, which is central to the ascription of meaning and adaptive updating of these patterns. Similar to Jacob von Uexküll’s idea of an ‘inner world’ emerging from action-perception cycles (Von Uexkull, 1957), for Damásio (2000) an ‘image’ of the body serves as reference for the coordination of adaptive action in the world; in a later phase, this image also anticipates future events, setting ‘goals’ for the system. Therefore, an action-perception cycle contains not only action and perceptual events, but the whole of subjective experience, including a multitude of unconscious processes. The claim that cycles of action-perception are constitutive of conscious experience does not imply that actual muscle activity is necessary for the formation of conscious episodes, nor for a transition between episodes. It is possible to form sequences of conscious episodes while dreaming, or while all skeletal muscles are paralyzed, because previous experiences were ‘internalized’, allowing the brain to function in ‘simulation mode’ (two plausible conjectures about the simulation process can be found in Revonsuo, 2006 and Humphrey, 2006). Motor cortex activity is thus not necessary for the formation of conscious episodes. However, for the reasons given above, on both phylogenetic and ontogenetic scales conscious experience would require present or at least past interaction with the rest of the body and environment. If subjective experience is conceived in terms of temporal cycles, it is mainly built from unconscious components. Patterns that form conscious episodes emerge from unconscious processing, and soon return to unconsciousness. Some of them stay dormant and are recalled later,


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but given the dynamical interplay of conscious and unconscious processes, the newer episode is never exactly like the recalled one. In the study of conscious experiences we are faced with a ‘continuum’ of conscious and unconscious aspects that is not taken into account in traditional concepts of ‘phenomenal experience’ or ‘flux of consciousness’, since the first implies that experience should be completely conscious, while the second implies that the conscious flux ought to be sharply distinguished from unconscious processes. Individual conscious experiences can be partially shared with other individuals. In social life, their cycles intersect each other, forming larger, collective cycles with conscious and unconscious aspects common to the group. In this kind of context, there is a possibility that closely interacting individuals can develop forms of social consciousness, as a second level of organization based on individual experiences. The concepts of ‘archetype’ and ‘meme’ express the existence of mental patterns present and influential both for the individual and the group. In the individual, they possibly constitute attractors in the brain´s dynamical landscape (Nunn, 2007). In the group, their grounding may well be on intersecting individual action-perception cycles. In spite of substantial efforts (such as Ellis, 1995), the importance of action-perception cycles for conscious experiences has not been universally recognized. For instance, in philosophical thought experiments it is commonly proposed that beings with behaviour identical to a conscious being need not be conscious at all. This assumption implies that consciousness is epiphenomenal (i.e. would have no causal powers on behaviour). In this regard, three logical possibilities were advanced by Baldwin (as long ago as 1896) for interpreting the evolutionary relation between consciousness and adaptive control of action. First, that consciousness was pre-existent and allowed adaptive action control — so that consciousness drove (some) evolutionary processes. Second, that action control existed before consciousness, considered to be an epiphenomenon. Third, a co-evolutionary view that consciousness and action control develop in interdependence. In the last view — more adequate to our claims in this section — the relation is contingent but (considered to be) causally effective. Epiphenomenalism conflicts with assumptions made in the context of scientific research on consciousness and in our everyday life. In the context of social human sciences, consciousness is often regarded as the phenomenon that enables us to act voluntarily and then have moral responsibility regarding other human beings. Psychologists, under the influence of Behaviourism, were reluctant to recognize this fact, but

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the winds of fashion have turned. For example, Dulany (2008) reports that ‘I can say this of studies I read in a range of psychology journals, including those submitted to me in my 20 years as Editor of the American Journal of Psychology: it seemed rather clear to me that conscious states and contents of the experimental subjects were centrally and causally involved in the production of their experimental effects’. Physiologically, it is arguable that the closest brain correlates of consciousness are dynamical processes that influence motor cortex activity. Ezequiel Morsella convincingly argued (see his PRISM principle in Morsella, 2005) that conscious processing is necessary for the coordination of skeletal muscles, but not for the control of other muscles or glands. The physiological architecture that makes coordination of a class of muscles dependent on conscious processing is considered to be the result of evolutionary processes. Based on this fact, every time animals execute voluntary actions the scientific observer would correctly infer that the behaviour is coordinated by conscious patterns embodied in brain activity. Considerations of the sort offered above suggest that the study of behaviour can reveal at least part of a person’s subjectivity, because aspects of conscious content can be expected to manifest in the results of action. From a practical point of view, however, it is of course often difficult to distinguish what originates in conscious processing from what comes from other sources.

‘Qualia’ as the Conscious Aspect of Subjective Experiences In the ever growing literature of the emerging science of consciousness, debates about ‘qualia’ are classics (Block, 1994; 2004; Brook and Raymond, 2004; Blackmore, 2005; Tye, 2007), yet some of the usual understandings of the term may not fit the actual natural phenomena particularly well. For instance, Tim Crane states that ‘it seems to me that there is not a clear consensus about how the term ‘qualia’ should be understood, and to this extent the contemporary problem of consciousness is not well-posed’ (Crane, 2000). A ‘quale’ (plural ‘qualia’), according to the dictionary, is a thing with a quality. In our context: conscious experience with a quality. A problem that led to confusion in our debates about ‘qualia’ is how they are defined. One extreme wanted an atomistic approach derived from the old logical-empiricist notion of ‘sense data’ (see Crane, 2000), narrowing ‘quale’ down to the redness of something red, for example, while others wanted the term to refer to the entire contents of an actual ‘moment’ of subjective experience (the content of William James’ ‘specious present’). Others attempted to deny the need for such a


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concept, perhaps following Dennett (1988), who does not deny the existence of conscious experience as such — he just denies that the qualities of conscious experience are special and need a special term for their description. The attribution of a ‘quality’ — an individual signature — to experience indicates the impossibility of a complete translation of firstperson into second or third-person perspectives. We can and do find ways to describe the conscious aspect of subjective experiences in proper scientific terms, but there remain in principle gaps that are based in the very nature of subjective experience. Because of these subjective properties, we argue that the term ‘qualia’ is well chosen and meaningful. Future research may clarify how far an objective scientific description of subjective experience will be possible. Our earlier argument implies both that the term ‘qualia’ is useful and that its meaning should follow from more general properties of subjective experiences: 1. they occur in the present only, 2. they are complex, 3. they are not repeatable and also 4. they are not fully retrievable. 1.

2.

3.

4.

As ‘qualia’ are (the subjective aspect of) experiences, they cannot happen in the future or in the past. We just experience whatever we experience in the present; indeed, in a sense they constitute the present as far as we are concerned. The complexity of experience is undisputed. There are different views on how experience is composed. In conscious binding many visual features that happen in front of our eyes, are bound into a meaningful picture or scene. Visual scenes, auditory experiences, emotions, thoughts and other experiences are also bound into unified experiences. This complexity poses serious challenges to acquiring full knowledge of what has actually been experienced. Any experience can not be exactly repeated. This is so because all the interactions that compose the experience are going on all the time. And with this process, features of the inner as well as the outer world are constantly changing, and also the representation of both worlds. Thus no experience is exactly like any other. This is basically an insight that goes back to Heraclitus: ‘You cannot step into the same river twice’. Thus the uniqueness of any conscious experience is established. No memory can enable anyone to exactly recall a past experience. No conceivable recording device will be able to fully record every aspect of what someone has consciously experienced.

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In this theoretical framework, the human individual does not seem to have an unchangeable ‘Self’ or center. On the contrary: Human beings seem to be changing constantly. We have moods, we have rhythms, we have thought processes, we have unresolved matters that occupy the mind even if we am not aware of them and still they may affect to the subjective space we are in at that very moment when we experience something. This account seems to describe our natural situation. We know what we experience, but much of that knowledge is constantly and irretrievably lost. This is the natural way human experience is happening.

Concluding Remarks Our attempt to identify a referential nucleus from Cognitive Neuroscience practices (reflected in the more scientific contributions to the debate) has led to a preliminary definition, which may provide a useful component of the terminology of some future science of consciousness. However, we are aware that it needs further modification in the light of contributions from e.g. Psychodynamics and other relevant fields, to overcome limitations of experimental settings that simplify conscious experiences, narrowing them to fragments correlated with measured brain activity and behaviour. We identified the referential nucleus as ‘reportable content experienced by living individuals’ and then expanded this to a broader concept, which can be expressed by a conjunction of statements: consciousness is a process that occurs in a subject (the living individual) & the subject has an experience (he/she interacts with the environment, completing action-perception cycles) & the experience has reportable informational content (information patterns embodied in brain activity that can be conveyed by means of voluntary motor activity). Consciousness, according to this definition, requires content, a subject to experience the content as meaningful (e.g. as belonging to adaptive perception-action cycles), and a link of the content with the subject’s behaviour, making possible partial communication of the content patterns to others. Human consciousness has to be understood as a product of a long process of evolution in which it has been shaped by cycles that include action, perception, memory, cognition, interpretation, etc. However, much of what is necessary for conscious experience has unconscious underpinnings. A sharp separation of conscious and unconscious processes may turn out to be not practical even if desirable. The main task for a future science of consciousness may be to discover which


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unconscious mechanisms we need to understand and explain, if only in order to help us to live responsible lives.

Acknowledgements To CNPQ (for the concession of a Research Fellowship to APJ); to Bernard Baars for careful criticisms about our project; to Chris Nunn, for his work on this subject, the invitation to submit to JCS and detailed comments to a previous version, and to everyone who contributed to our online discussions. References Baars, B. (1988), A Cognitive Theory of Consciousness (New York: Cambridge University Press), p. 448. Baars, B. (1997), In the Theater of Consciousness: The Workspace of the Mind (New York: Oxford), p. 210. Baldwin, J.M. (1896), ‘Consciousness and Evolution’, Psychological Review 3, pp. 300–9, http://www.brocku.ca/MeadProject/Baldwin/Baldwin_1896_b.html Blackmore, S. (2005), Conversations on Consciousness (Oxford: Oxford University Press). Block, N. (1994), ‘Qualia’, in S. Guttenplan (Ed.), A Companion to Philosophy of Mind (Oxford: Blackwell), http://www.nyu.edu/gsas/dept/philo/faculty/ block/papers/Qualia_from_Guttenplan.pdf. Block, N. (2004), ‘Qualia: What it is like to have an experience’, in R. Gregory (Ed.), Oxford Companion to the Mind, Second Edition, http://www.nyu.edu/ gsas/dept/philo/faculty/block/papers/qualiagregory.pdf. Brook, A. & Raymond, P. (2004), The Unity of Consciousness, Stanford Encyclopedia of Philosophy, http://plato.stanford.edu/entries/consciousness-unity/ Brook, A. (2008), ‘Terminology in Consciousness Studies’, http://www.ym.edu. tw/assc12/notie/tutorials_ntie.html#02. Chalmers, D. (1996), The Conscious Mind (New York: Oxford University Press), p. 414. Chalmers, D. (2000), ‘What is a Neural Correlate of Consciousness?’ In Metzinger, T. (Ed.), Neural Correlates of Consciousness: Empirical and Conceptual Questions (Cambridge, MA: MIT Press), pp. 17–40. Clark, A. (1997), Being There: Putting brain, body, and world together again (Cambridge, MA: MIT Press), p. 280. Clark, A. & Chalmers, D. (1998), ‘The Extended Mind’, Analysis, 58, pp. 10–23, http://consc.net/papers/extended.html. Crane, T. (2000), ‘The Origins of Qualia’, In T. Crane & S. Patterson (Ed.), The History of the Mind-Body Problem (London: Routledge), http://web.mac.com/ cranetim/Tims_website/Online_papers_files/The%20origins%20of%20qualia. pdf. Crick, F.C. & Koch, C. (1998), ‘Consciousness and Neuroscience’, Cerebral Cortex, 8, pp. 97–107. Damásio, A. (2000), The Feeling of What Happens: Body and Emotion in the Making of Consciousness (New York: Harcourt), p. 400. Dennett, D. (1988), ‘Quining Qualia’, in A. Marcel & E. Bisiach (Ed.), Consciousness in Modern Science (Oxford University Press), http://ase.tufts.edu/cogstud/ papers/quinqual.htm.

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Dulany, D.E. (2008), ‘How Well Are We Moving Toward a Most Productive Science of Consciousness?’ Journal of Consciousness Studies, 15 (12), pp. 75–98. Ellis, R.D. (1995), Questioning Consciousness; The interplay of imagery, cognition and emotion in the human brain (John Benjamins). Freeman, W. & Schneider, W. (1982), ‘Changes in Spatial Patterns of Rabbit Olfactory EEG with Conditioning to Odors’, Psychophysiology, 19, pp. 44–56. Freeman, W. (1995), Societies of Brains: A Study in the Neuroscience of Love and Hate (Hillsdale, NJ: Lawrence Erlbaum), p. 171. Frith, C., Perry, R. & Lumer, E. (1999), ‘The Neural Correlates of Conscious Experience: An Experimental Framework’, Trends in Cognitive Sciences, 3 (3), pp. 105–14. Hacking, I. (1983), Representing and Intervening: Introductory Topics in the Philosophy of Natural Science (Cambridge: Cambridge University Press), p. 287. Humphrey, N. (2006), Seeing Red: A study in consciousness (Cambridge-MA and London: Harvard University Press), p. 151. Morsella, E. (2005), ‘The Function of Phenomenal States: Supramodular Interaction Theory’, Psychological Review, 112, pp.1000–21. Nagel, T. (1974), ‘What is it Like to be a Bat?’ The Philosophical Review, 83 (4), pp. 435–50, http://members.aol.com/NeoNoetics/Nagel_Bat.html. Nixon, G. (2007), ‘The Continuum of Experience: Non-Conscious Experience’, Karl Jaspers Forum TA95A, http://www.kjf.ca/95A-TANIX.htm Nunn, C. (2007), From Neurons to Notions: Brains, Minds and Meaning (Edinburgh: Floris Books), p. 208. Pereira, A. & Furlan, F. (2007), ‘Biomolecular Information, Brain Activity and Cognitive Functions’, Annual Review of Biomedical Sciences, 9, pp. 12–29. Revonsuo, A. (2006), Inner Presence: Consciousness as a Biological Phenomenon (Cambridge: MIT Press), p. 499. Searle, J. (2000), ‘Consciousness’, Annual Review of Neuroscience, 23, pp. 557–78. Seth, A.K., Izhikevich, E., Reeke, G.N. & Edelman, G.M. (2006), ‘Theories and Measures of Consciousness: An extended framework’, Proceedings of the National Academy of Sciences USA, 103 (28), pp. 10799–804. Trehub, A. (1991), The Cognitive Brain (Cambridge, MA.: MIT Press), p. 342. Trehub, A. (2008), Contribution to the Forum ‘The Quest for a Definition of the Term “Consciousness”’, posted May 26, http://network.nature.com/forums/ bpcc/1585. Vakalopoulos, C. (2005), ‘Neural Correlates of Consciousness: A definition of the dorsal and ventral streams and their relation to phenomenology’, Medical Hypotheses, 65 (5), pp. 922–31. Varela, F. J., Thompson, E. & Rosch, E. (1991), The Embodied Mind: Cognitive science and human experience (Cambridge: MIT Press), pp. 292. Velmans, Max (1993), ‘A Reflexive Science of Consciousness’, In Ciba Foundation Symposium 174, Experimental and Theoretical Studies of Consciousness (Chichester: John Wiley & Sons), pp. 81–99. Von Uexkull, J. (1957), ‘A Stroll Through the Worlds of Animals and Men’, In C.H. Schiller (Ed.), Instinctive Behavior (New York: International Universities Press). Tye, M. (2007), Qualia, Stanford Encyclopedia of Philosophy, http://plato. stanford.edu/entries/qualia/.