In his recent (2005) book "Sweet Dreams: philosophical obstacles to a science of consciousness," Dennett renews his attack on a philosophical notion of qualia, the success of which attack is required if his brand of Functionalism is to survive. He also articulates once again what he takes to be essential to his notion of consciousness. I shall argue that his new, central argument against the philosophical concept of qualia fails. In passing I point out a difficulty that David Rosenthal's "higher-order (...) thought" theory of consciousness also faces in accounting for qualia. I then contrast Dennett's newest account of consciousness with interestingly different conceptions by contemporary neuro-scientists, and I suggest that philosophers should take the recent suggestions by neuro-scientists more seriously as a subject for philosophical investigation. (shrink)

Surgical patients under anesthesia can wake up unpredictably and be exposed to intense, traumatic pain. Current medical techniques cannot maintain depth of anesthesia at a perfectly stable and safe level; the depth of unconsciousness may change from moment to moment. Without an effective consciousness monitor anesthesiologists may not be able to adjust dosages in time to protect patients from pain. An estimated 40,000 to 200,000 midoperative awakenings may occur in the United States annually. E. R. John and coauthors present the (...) scientific basis of a practical ''consciousness monitor'' in two articles. One article is empirical and shows widespread and consistent electrical field changes across subjects and anesthetic agents as soon as consciousness is lost; these changes reverse when consciousness is regained afterward. These findings form the basis of a surgical consciousness monitor that recently received approval from the U.S. Food and Drug Administration. This may be the first practical application of research on the brain basis of consciousness. The other John article suggests theoretical explanations at three levels, a neurophysiological account of anesthesia, a neural dynamic account of conscious and unconscious states, and an integrative field theory. Of these, the neurophysiology is the best understood. Neural dynamics is evolving rapidly, with several alternative points of view. The field theory sketched here is the most novel and controversial. (shrink)

In his 1996 paper Neurophenomenology: A methodological remedy for the hard problem, Francisco Varela called for a union of Husserlian phenomenology and cognitive science. Varela''s call hasn''t gone unanswered, and recent years have seen the development of a small but growing literature intent on exploring the interface between phenomenology and cognitive science. But despite these developments, there is still some obscurity about what exactly neurophenomenology is. What are neurophenomenologists trying to do, and how are they trying to do it? To (...) what extent is neurophenomenology a distinctive and unified research programme? In this paper I attempt to shed some light on these questions. (shrink)

The contribution argues that causal interpretations of empirical correlations between neural and conscious events are meaningful even if not fully verifiable and that there are reasons in favour of an epiphenomenalist construction of psychophysical causality. It is suggested that an account of causality can be given that makes interactionism, epiphenomenalism and Leibnizian parallelism semantically distinct interpretations of the phenomena. Though neuroscience cannot strictly prove or rule out any one of these interpretations it can be argued that methodological principles favour a (...) causal interpretation on epiphenomenalist lines, both for reasons of metaphysical parsimony and for reasons of coherence with established physical principles such as the conservation of energy. In the concluding chapter, some of the philosophical and the empirical challenges following from this model are outlined, the most important being closer scrutiny of the neurophysiological processes accompanying conscious volition. (shrink)

How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We can see the problem in stark form if we ask how we could tell whether representations inside a Fodorian module are phenomenally conscious. The methodology would seem straightforward: find the neural natural kinds that are the basis of phenomenal consciousness in clear cases when subjects are completely confident and we have no reason to doubt their (...) authority, and look to see whether those neural natural kinds exist within Fodorian modules. But a puzzle arises: do we include the machinery underlying reportability within the neural natural kinds of the clear cases? If the answer is ‘Yes’, then there can be no phenomenally conscious representations in Fodorian modules. But how can we know if the answer is ‘Yes’? The suggested methodology requires an answer to the question it was supposed to answer! The paper argues for an abstract solution to the problem and exhibits a source of empirical data that is relevant, data that show that in a certain sense phenomenal consciousness overflows cognitive accessibility. The paper argues that we can find a neural realizer of this overflow if assume that the neural basis of phenomenal consciousness does not include the neural basis of cognitive accessibility and that this assumption is justified (other things equal) by the explanations it allows. (shrink)

The search for neural correlates of consciousness (or NCCs) is arguably the cornerstone in the recent resurgence of the science of consciousness. The search poses many difficult empirical problems, but it seems to be tractable in principle, and some ingenious studies in recent years have led to considerable progress. A number of proposals have been put forward concerning the nature and location of neural correlates of consciousness. A few of these include.

*[[This paper appears in _Toward a Science of Consciousness II: The Second Tucson Discussions and Debates_ (S. Hameroff, A. Kaszniak, and A.Scott, eds), published with MIT Press in 1998. It is a transcript of my talk at the second Tucson conference in April 1996, lightly edited to include the contents of overheads and to exclude some diversions with a consciousness meter. A more in-depth argument for some of the claims in this paper can be found in Chapter 6 of my (...) book _The Conscious Mind_ (Chalmers, 1996). ]]. (shrink)

The Hurvich-Jameson (H-J) opponent-process network offers a familiar account of the empirical structure of the phenomenological color space for humans, an account with a number of predictive and explanatory virtues. Its successes form the bulk of the existing reasons for suggesting a strict identity between our various color sensations on the one hand, and our various coding vectors across the color-opponent neurons in our primary visual pathways on the other. But anti-reductionists standardly complain that the systematic parallels discovered by the (...) H-J network are just empirical correspondences, constructed post facto, with no predictive or explanatory purchase on the intrinsic characters of qualia proper. The present paper disputes that complaint, by illustrating that the H-J model yields some novel and unappreciated predictions, and some novel and unappreciated explanations, concerning the qualitative characters of a considerable variety of color sensations possible for human experience, color sensations that normal people have almost certainly never had before, color sensations whose accurate descriptions in ordinary language appear semantically ill-formed or even self-contradictory. Specifically, these "impossible" color sensations are activation-vectors (across our opponent-process neurons) that lie inside the space of neuronally possible activation-vectors, but outside the central 'color spindle' that confines the familiar range of sensations for possible objective colors. These extra-spindle chimerical-color sensations correspond to no reflective color that you will ever see objectively displayed on a physical object. But the H-J model both predicts their existence and explains their highly anomalous qualitative characters in some detail. It also suggests how to produce these rogue sensations by a simple procedure made available in the latter half of this paper. The relevant color plates will allow you to savor these sensations for yourself. (shrink)

and denotes a number of different phenomena. We reason about “consciousness” using some premises that apply to one of the..

Research on consciousness is currently enjoying a spectacular revival of interest in the cognitive sciences. From an empirical point of view, the NCC program — the search for the “Neural Correlates of Consciousness” — holds the promise of establishing correlations between physiological and phenomenal states in a way that directly resembles G. T. Fechner´s (1860) so-called “inner psychophysics”. Should the NCC program be entirely successful, we would thus be able to predict phenomenal states based on physiological states. we would be (...) able to predict phenomenal states based on physiological states. In this paper, we explore some of the conceptual and methodological difficulties of this approach. In both neurobiology and psychology, there are serious measurement problems that stand in the way of correlation research, even after the “hard problem” has been set aside. Thus, even if one had identified certain internal functional states as indicators of phenomenal states, the empirical psychologist would still be confronted with fundamental problems, such as determining the absence or presence of these functional states. In this respect, philosophy of science may help and provide a metatheoretical framework for the current interdisciplinary project. (shrink)

Cognitive functions associated with the frontal lobes of the brain may be specifi cally involved in hypnosis. Thus, the frontal area of the brain has recently been of great interest when searching for neural changes associated with hypnosis. We tested the hypothesis that EEG during pure hypnosis would differ from the normal non-hypnotic EEG especially above the frontal area of the brain. The composition of brain oscillations was examined in a broad frequency band (130 Hz) in the electroencephalogram (EEG) of (...) a single virtuoso subject. Data was collected in two independent data collection periods separated by one year. The hypnotic and non-hypnotic conditions were repeated multiple times during each data acquisition session. We found that pure hypnosis induced reorganization in the composition of brain oscillations especially in prefrontal and right occipital EEG channels. Additionally, hypnosis was characterized by consistent rightside-dominance asymmetry. In the prefrontal EEG channels the composition of brain oscillations included spectral patterns during hypnosis that were completely different from those observed during non-hypnosis. Furthermore, the EEG spectral patterns observed overall during the hypnotic condition did not return to the pre-hypnotic baseline EEG immediately when hypnosis was terminated. This suggests that for the brain, the return to a normal neurophysiological baseline condition after hypnosis is a time-consuming process. The present results suggest that pure hypnosis is characterized by an increase in alertness and heightened attention, refl ected as cognitive and neuronal activation. Taken together, the present data provide support for the hypothesis that in a very highly hypnotizable person (a hypnotic virtuoso) hypnosis as such may be accompanied by a changed pattern of neural activity in the brain. (shrink)

Spelling out in detail what we do and do not know about phenomenological experience, this book denies the common view of consciousness as a central decision...

Most consciousness researchers, almost no matter what their views of the metaphysics of consciousness, can agree that the first step in a science of consciousness is the search for the neural correlate of consciousness (the NCC). The reason for this agreement is that the notion of ‘correlation’ doesn’t by itself commit one to any particular metaphysical view about the relation between (neural) matter and consciousness. For example, some might treat the correlates as causally related, while others might view the correlation (...) as evidence for identity between conscious states and brain states. The common ground therefore seems to be that the scientific search for the NCC is largely independent of the metaphysics of consciousness. (shrink)

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Since Francis Crick popularized the term `Neural Correlate of Consciousness' (NCC), it has been the focus of what is perhaps the most exciting research area in the cognitive sciences. Different researchers and laboratories have offered different brain structures as candidates for the NCC prize. Different chunks of gray matter have been identified as the potential seat of consciousness. Some researchers attempt to identify the NCC via a characterization of the cognitive aspects of consciousness, such as its functional significance or intentional (...) directedness, while others attempt a direct identification of the NCC, without any cognitive intermediary. Needless to say, no consensus is in sight on any of this. (shrink)

& Functional brain imaging offers new opportunities for the begin with single-subject (preprocessed) scan series, and study of that most pervasive of cognitive conditions, human consider the patterns of all voxels as potential multivariate consciousness. Since consciousness is attendant to so much encodings of phenomenal information. Twenty-seven subjects of human cognitive life, its study requires secondary analysis from the four studies were analyzed with multivariate of multiple experimental datasets. Here, four preprocessed methods, revealing analogues of phenomenal structures, datasets from the (...) National fMRI Data Center are considered: particularly the structures of temporality. In a second Hazeltine et al., Neural activation during response competi- interpretive approach, artificial neural networks were used tion; Ishai et al., The representation of objects in the human to detect a more explicit prediction from phenomenology, occipital and temporal cortex; Mechelli et al., The effects of namely, that present experience contains and is inflected by presentation rate during word and pseudoword reading; and past states of awareness and anticipated events. In all of 21 Postle et al., Activity in human frontal cortex associated with subjects in this analysis, nets were successfully trained to spatial working memory and saccadic behavior. The study of extract aspects of relative past and future brain states, in consciousness also draws from multiple disciplines. In this comparison with statistically similar controls. This exploratory article, the philosophical subdiscipline of phenomenology study thus concludes that the proposed methods for provides initial characterization of phenomenal structures ‘‘neurophenomenology’’ warrant further application, includ- conceptually necessary for an analysis of consciousness. These ing the exploration of individual differences, multivariate structures include phenomenal intentionality, phenomenal differences between cognitive task conditions, and explora- superposition, and experienced temporality.. (shrink)

The neurophilosophy of consciousness brings neuroscience to bear on philosophical issues concerning phenomenal consciousness, especially issues concerning what makes mental states conscious, what it is that we are conscious of, and the nature of the phenomenal character of conscious states. Here attention is given largely to phenomenal consciousness as it arises in vision. The relevant neuroscience concerns not only neurophysiological and neuroanatomical data, but also computational models of neural networks. The neurophilosophical theories that bring such data to bear on the (...) core philosophical issues of phenomenal conscious construe consciousness largely in terms of representations in neural networks associated with certain processes of attention and memory. (shrink)

In the past decade, the notion of a neural correlate of consciousness (or NCC) has become a focal point for scientific research on consciousness (Metzinger, 2000a). A growing number of investigators believe that the first step toward a science of consciousness is to discover the neural correlates of consciousness. Indeed, Francis Crick has gone so far as to proclaim that ‘we … need to discover the neural correlates of consciousness.… For this task the primate visual system seems especially attractive.… No (...) longer need one spend time attempting … to endure the tedium of philosophers perpetually disagreeing with each other. Con- sciousness is now largely a scientific problem’ (Crick, 1996, p. 486).2 Yet the question of what it means to be a neural correlate of consciousness is actually far from straightforward, for it involves fundamental empirical, methodological, and _philosophical _issues about the nature of consciousness and its relationship to the brain. Even if one assumes, as we do, that states of consciousness causally depend on states of the brain, one can nevertheless wonder in what sense there is, or could be, such a thing as a neural correlate of consciousness. (shrink)

The neurobiological systems that mediate the basic emotions are beginning to be understood. They appear to be constituted of genetically coded, but experientially refined executive circuits situated in subcortical areas of the brain which can coordinate the behavioral, physiological and psychological processes that need to be recruited to cope with a variety of primal survival needs (i.e., they signal evolutionary fitness issues). These birthrights allow newborn organisms to begin navigating the complexities of the world and to learn about the values (...) and contingencies of the environment. Some of these systems have been identified and characterized using modern neuroscientific and psychobiological tools. The fundamental emotional systems can now be defined by the functional psychobiological characteristics of the underlying circuitries ? characteristics which help coordinate behavioral, physiological and psychological aspects of emotionality, including the valenced affective feeling states that provide fundamental values for the guidance of behavior. The various emotional circuits are coordinated by different neuropeptides, and the arousal of each system may generate distinct affective/neurodynamic states and imbalances may lead to various psychiatric disorders. The aim of this essay is to discuss the underlying conceptual issues that must be addressed for additional progress in understanding the nature of primary process affective consciousness. (shrink)

This paper concentrates on the basic properties of ''consciousness'' that temporal coding is postulated to relate to. A description of phenomenal consciousness based on what introspection tells us about its contents is offered. This includes a consideration of the effect of various brain lesions that result in cortical blindness, apperceptive and associative agnosia, and blindsight, together with an account of the manner in which sight is regained after cortical injuries. I then discuss two therories of perception-Direct Realism and the Representative (...) Theory. This includes a discussion of the concept of the body-image, phantom limbs, the alleged projection of sensations, the ontological status of phenomenal space, the homunculus argument, the validity of topographic coding, the difference between the stimulus field and the visual field, and two theories of brain-mind relationship-the Identity Theory and the Bohr-Heisenberg theory of brain-mind complementarity. Finally I suggest that the binocular rivalry obtained in the case of the stroboscopic patterns that result from intermittent photic stimulation of one eye, when used in animal expeiments with unit recording, offers a good experimental method of investigating the binding problem. (shrink)