Gray hypothesizes that the contents of consciousness correspond to the outputs of a subicular (hippocampal/temporal lobe) comparator that compares the current state of the organism's perceptual world with a predicted state. I argue that Gray has identified a key contributing system to conscious awareness, but that his model is inadequate for explaining how conscious contents are generated in the brain. An alternative model is offered.

Gray's neuropsychological model of consciousness uses a hierarchical feedback loop framework that has been extensively discussed by many others in psychology. This commentary therefore urges Gray to integrate with, or at least acknowledge previous models. It also points out flaws in his feedback model and suggests directions for further theoretical work.

A-consciousness may be regarded as the visibility of information that is the output of a process within a community of other processes. The most prominent function of “public” dissemination of information is giving access to it to processes whose relevance is not clear at the moment of dissemination. The function of P-consciousness may be outside the realm of cognition.

In response to the objection that his “access-consciousness” is not really consciousness but a matter of the availability of certain information for certain kinds of processing, Block will probably have to argue that consciousness in a more basic, familiar, traditional sense is an essential component of any instance of access-consciousness and thus justifies the name.

Habit and Embodiment in Merleau-PontyIntroductionMerleau-Ponty (French phenomenological philosopher, born in 1908 and deceased in 1961) refers to habit in various passages of his Phenomenology of Perception as a relevant issue in his philosophical and phenomenological position. Through his exploration of this issue he explains both the pre-reflexive character that our original linkage with the world has, as well as the kind of “understanding” that our body develops with regard to the world. These two characteristics of human existence bear a close (...) relation with the vision of an embodied mind sustained by Gallagher and Zahavi in their work The Phenomenological Mind: An Introduction to Philosophy of Mind and Cognitive Science. Merleau-Ponty uses concepts like those of the lived or own body and of lived space in order to emphasize, from a first-person perspective, the co-penetration that exists between subject and world.Gallagher and Zahavi have regained the experience of phenomenology, especially that of Merleau-Ponty and Sartre, to contribute to the development of the cognitive sciences. Via the phenomenological approach to the reality of habit, a new understanding of the body becomes possible for us, such that it becomes characterized “as subject, as experiencer, as agent”, and at the same time we can understand “the way the body structures our experience” (Gallagher and Zahavi, 2008). Additionally, the idea of a pre-reflexive understanding is conceived of by these authors... (shrink)

In common sense consciousness has a fairly determinate content – the (single) way an experience feels, the (single) line of thought being consciously followed. The determinacy of the object may be achieved by linking Block's two concepts, so that as long as we hold on to the determinacy of content we are unable to separate P and A.

Research Articles Michael S. Moore, Social Philosophy and Policy, FirstView Article.

Event-related potentials (ERPs) – neglected almost entirely by Wright & Liley – allow objective investigation of information processing in the brain. The application of chaos theory to such an analysis broadens this possibility. Through the use of the point correlation dimension (PD2) accurate dimensional analysis of different Event-Related Potential components such as the P3 wave is possible.

Simulation of brain dynamics requires the use of accurate empirical data. This commentary points out major errors in some of the empirical data used in Wright & Laley's simulation. The simulation is quantitatively very different from the real cortex, and may also have important qualitative differences.

The comparator model is insufficient for three reasons. First, consciousness is involved in the process of comparison as well as in the output. Second, we still do not have enough neurophysiological information to match the events of consciousness, although such knowledge is growing. Third, the anatomical localisation proposed can be damaged bilaterally but consciousness will persist.

What does free will mean to laypersons? The present investigation sought to address this question by identifying how laypersons distinguish between free and unfree actions. We elicited autobiographical narratives in which participants described either free or unfree actions, and the narratives were subsequently subjected to impartial analysis. Results indicate that free actions were associated with reaching goals, high levels of conscious thought and deliberation, positive outcomes, and moral behavior (among other things). These findings suggest that lay conceptions of free will (...) fit well with the view that free will is a form of action control. (shrink)

With no statutory definition of death, the accepted medical definition relies on brain stem death criteria as a definitive measure of diagnosing death. However, the use of brain stem death criteria in this way is precarious and causes widespread confusion amongst both medical and lay communities. Through critical analysis, this paper considers the insufficiencies of brain stem death. It concludes that brain stem death cannot be successfully equated with either biological death or the loss of integrated bodily function. The overemphasis (...) of the brain-stem and its consequences leaves the criteria open to significant philosophical critique. Further, in some circumstances, the use of brain stem death criteria causes substantial emotional conflict for families and relatives. Accordingly, a more holistic and comprehensive definition of death is required. (shrink)

This commentary challenges the authors to use their computational modeling techniques to support one of their central claims: that schizophrenic deficits in bottom-up (Gestalt-type tasks) and top-down (cognitive control tasks) context processing tasks arise from the same dysfunction. Further clarification about the limits of cognitive coordination would also strengthen the hypothesis.

Block contends that the concept of consciousness is a mongrel concept and that researchers go astray by conflating different notions of “consciousness.” This is certainly true. In fact, it is truer than Block acknowledges, because his own notion of P-consciousness runs together two, or arguably three, quite different and separable features of a sensory state.

The aim of this work was to elaborate on the author’s previously published hypothesis of the Soul of Multiverse, a suggested cosmic phenomenon that also appears to imbue the human Soul across its individual and noospheric scales. Without alternatives, the method of analysis continued to rely on the approach of cosmological neuroscience, which integrates scientific facts, religious insights, philosophical suggestions, engineering rules and artistic tools to grasp the complexity of the multidimensional phenomenon of Soul. The result of this examination was (...) the multilayered thought that just as the central medium of human Soul, the hypothesized prefrontal cortical supercircuitry of Self-Ken, seems to comprise domains representing Identity, Conscience, Will and Mission, analogous domains may also function in the noospheric and cosmic Souls. Regarding the human Soul, its four domains appear to be determined by both hereditary genetic and encountered environmental factors to present its host with a Mission enabling his or her mental engine and physical features to integrate into the surrounding society and space-time in the most meaningful and dignified way—if that way is undertaken. Regarding the noospheric Soul, it is made of individual human Souls interacting with the non-living system of interconnected computers to produce functions accessible to humans all over the world through uncontrolled communication across the Internet. Its most probable Mission is to let this global presence acquire its own Identity, develop its own Conscience and refine its own Will, so that their coherent, superior whole can be ready for sensing the cosmic Soul. Regarding the cosmic Soul, the hypothesized Soul of the Multiverse, its Identity appears to express the Laws of Mystery of Endlessness, Coexistence in Diversity, and Truth in Complexity. Further, its Conscience seems to be moved by the Law of Divine—Evil Asymmetry, its Will by the Law of Determination with Uncertainty, and its Mission by the Law of Lives to Transcend. (shrink)

To avoid teleological interpretations, it is important to make a distinction between functions and uses of consciousness, and to address questions concerning the consequences of consciousness. Assumptions about the phylogenetic distribution of consciousness are examined. It is concluded that there is some value in identifying consciousness an exclusively human attribute.

The information processing that constitutes accessconsciousness is not sufficient to make a representational state conscious in any sense. Standard examples of computation without consciousness undermine A-consciousness, and Block's cases seem to derive their plausibility from a lurking phenomenal awareness. That is, people and other minded systems seem to have access-consciousness only insofar as the state accessed is a phenomenal one, or the state resulting from access is phenomenal, or both.

Gray's integration of the different levels of description and explanation in his theory is problematic: The introduction of consciousness into his theorising consists of the mind-brain identity assumption, which tells us nothing new. There need not be correlations between levels of description. Gray's account does not extend beyond “brute” correlation. Integration must be achieved in a principled, mutually constraining way.

We present simulation results of an olfactory cortex model complementing the results presented in Wright & Liley's target article. We show how the cortical dynamics as expressed in EEG can be regulated by neuromodulation and discuss how the system can attain global stability without cortical-subcortical interaction, as presumed necessary by Wright & Liley. Network structure is shown to be crucial.

One of the major divergences between dynamical systems theory and symbolism lies in their views on the role of representation in cognition. From the perspective of development, the cognitive development could be divided into three levels: sensorimotor, imagery representation and linguistic representation. It is claimed that representation is not a sufficient condition though it is necessary for cognition. However, it does not mean that the authors agree with the notion of strong coupling in dynamicism that completely rejects representation.

Basically agreeing with Block regarding the need for a distinction between P- and A-consciousness, I characterize the problem somewhat diflerently, relating it more directly to the explanatory gap. I also speculate on the relation between the two forms of consciousness, arguing that some notion of access is essentially involved in phenomenal experience.

Schizophrenics exhibit a deficit in theory of mind (ToM), but an intact theory of biology (ToB). One explanation is that ToM relies on an independent module that is selectively damaged. Phillips & Silverstein's analyses suggest an alternative: ToM requires the type of coordination that is impaired in schizophrenia, whereas ToB is spared because this type of coordination is not involved.

The Gestalt principle of isomorphism reveals the primacy of subjective experience as a valid source of evidence for the information encoded neurophysiologically. This theory invalidates the abstractionist view that the neurophysiological representation can be of lower dimensionality than the percept to which it gives rise.

Posner & Raichle's (1994) book is a fascinating and readable account of the studies the authors have conducted on the localization of cognitive functions in the brain mainly using PET and EEC evoked potential methods. Our criticism concerns the underrepresentation of some imaging techniques (magnetoencephalography) and some forms of brain activity (spontaneous activity). Furthermore, the book leaves the reader with the impression that the brain only responds to external events.

We focus on one aspect of Wright & Liley's target article: the linearity of the EEG. According to the authors, some nonlinear models of the cortex can be reduced (approximated) to the linear case at the millimetric scale. We argue here that the statement about the linear character of EEG is too strong and that EEG exhibits nonlinear features which cannot be ignored.

To model the organization of levels' of cortical dynamics, at least some general scheme for hierarchy, functional diversity, and proper intrinsic control must be provided. Rhythmic control forces the system to iterate its state by short trajectories, which makes it much more stable and predictable without discarding the desirable ability of chaotic systems to make rapid phase transitions. Rhythmic control provides a fundamentally different systems dynamics, one not provided by models that allow the emergence of continuous trajectories in the systems (...) state space. (shrink)

Block's cases of superblindsight, the pneumatic drill, and the Sperling experiments do not show that P-consciousness and Aconsciousness can come apart. On certain tendentious but not implausible construals of the concepts of P- and A-consciousness, they refer to the same psychological phenomenon.

S. Pockett and G. Gomes discuss a possible bias in the method by which Libet's subjects estimated the time at which they became aware of their intent to move their hands. The bias, caused by sensory delay processing the clock information, would be sufficient to alter Trevena and Miller's conclusions regarding the timing of the lateralized readiness potential. I show that the flash-lag effect would compensate for that bias. In the last part of my commentary I note that the other (...) target articles do not examine the most interesting aspect of Libet's unfashionable views on free will. I point out that Libet's views are less strange than they at first appear to be. (shrink)

This commentary offers two criticisms of Block's account of phenomenal consciousness and a brief sketch of a rival account. The negative points are that monitoring consciousness also involves the possession of certain states and that phenomenal consciousness inevitably involves some sort of monitoring. My positive suggestion is that “phenomenal consciousness” may refer to our ability to monitor the rich but preconceptual states that retain perceptual information for complex processing.

Neurophysiological investigations of the past two decades have consistently demonstrated a deficit in sensory gating associated with schizophrenia. Phillips & Silverstein interpret this impairment as being consistent with cognitive coordination dysfunction. However, the physiological mechanisms that underlie sensory gating have not been shown to involve gamma-band oscillations or NMDA-receptors, both of which are critical neural elements in the cognitive coordination model.

As Gray insists, his comparator model proposes a brute correlation only – of consciousness with septohippocampal output. I suggest that the comparator straddles a feedback loop that boosts the activation ofnovelrepresentations, thus helping them feature in present or recollected experience. Such a role in organizing conscious contents would transcend correlation and help explain how consciousness emerges from brain function.

In this article, I present a novel approach to the scientific understanding of consciousness. It is based on the hypothesis that the full range of phenomenal qualities is built into the frequency spectrum of a ubiquitous background field and proceeds on the assumption that conscious systems employ a universal mechanism by means of which they are able to extract phenomenal nuances selectively from this field. I set forth that in the form of the zero-point field (ZPF) physics can offer a (...) promising candidate that is qualified for playing the dual role as both the carrier of energy and consciousness. The appropriate mechanism, which rests upon the principle of dynamical coupling of ZPF modes, is a unique feature of quantum systems, suggesting that the dividing line between conscious and non-conscious systems is defined by the differentiation between quantum systems and classical systems. The presence of this mechanism in the brain is supported by the neurophysiological body of evidence, leading to a consistent explanation of the dynamical properties of the neural correlates of consciousness. Building on these findings, I lay the foundations for the conceptually coherent integration of consciousness into the physical worldview, derive an indicator for the quantity of consciousness of a given system, and outline the further steps toward a theory of consciousness. (shrink)

One can share Block's aim of distinguishing “phenomenal” experience from cognitive function and agree with much in his views, yet hold that the inclusion of representational content within phenomenal content, if only in certain spatial cases, obscures this distinction. It may also exclude some modular theories, although it is interestingly suggestive of what may be the limits of the phenomenal penetration of the representational mind.

This is an excellent book but it lacks a detailed presentation and formulation of images of memory. Positron emission tomography (PET) findings sometimes raise more enigmatic questions than they answer, with differences between studies and differences with established lesion evidence. Perhaps the book could have been more critical in its analysis of these enigmas, covering more of the basic issues and assumptions underlying PET research.

Posner & Raichle illustrate how neuroimaging blends profitably with neuropsychology and electrophysiology to advance cognitive theory. Recognizing that there are limitations to each of these techniques, we nonetheless argue that their confluence has fundamentally changed the way cognitive psychologists think about problems of the mind.

N-methyl-d-aspartate receptor (NMDAR) dysfunction plays a crucial role in schizophrenia, leading to impairments in cognitive coordination. NMDAR agonists (e.g., glycine) ameliorate negative and cognitive symptoms, consistent with NMDAR models. However, not all types of cognitive coordination use NMDAR. Further, not all aspects of cognitive coordination are impaired in schizophrenia, suggesting the need for specificity in applying the cognitive coordination construct.

It is argued that current neuroimaging studies can provide useful constraints for the construction of models of cognition, and that these studies should be guided by cognitive models. A numberof challenges for a successful cross-fertilization between “mind mappers” and cognitive modelers are discussed in the light of current research on word recognition.

Most ?theories of consciousness? are based on vague speculations about the properties of conscious experience. We aim to provide a more solid basis for a science of consciousness. We argue that a theory of consciousness should provide an account of the very processes that allow us to acquire and use information about our own mental states ? the processes underlying introspection. This can be achieved through the construction of information processing models that can account for ?Type-C? processes. Type-C processes can (...) be specified experimentally by identifying paradigms in which awareness of the stimulus is necessary for an intentional action. The Shallice (1988b) framework is put forward as providing an initial account of Type-C processes, which can relate perceptual consciousness to consciously performed actions. Further, we suggest that this framework may be refined through the investigation of the functions of prefrontal cortex. The formulation of our approach requires us to consider fundamental conceptual and methodological issues associated with consciousness. The most significant of these issues concerns the scientific use of introspective evidence. We outline and justify a conservative methodological approach to the use of introspective evidence, with attention to the difficulties historically associated with its use in psychology. (shrink)

To explore the mechanism of sensation correlations between EP component amplitude and signal detection indices were studied. The time of sensation coincided with the peak latency of those EP components that showed a correlation with both indices. The components presumably reflected information synthesis in projection cortical neurons. A mechanism providing the synthesis process is proposed.

Posner & Raichle'sImages of mindis an excellent educational book and very well written. Some flaws as a scientific publication are: (a) the accuracy of the linear subtraction method used in PET is subject to scrutiny by further research at finer spatial-temporal resolutions; (b) lack of accuracy of the experimental paradigm used for EEG complementary studies.