Cognitive Models of Consciousness

This paper looks closely at previously enunciated axioms that specifically include phenomenology as the sense of a self in a perceptual world. This, we suggest, is an appropriate way of doing science on a first-person phenomenon. The axioms break consciousness down into five key components: presence, imagination, attention, volition and emotions. The paper examines anew the mechanism of each and how they interact to give a single sensation. An abstract architecture, the Kernel Architecture, is introduced as a starting point for (...) building computational models. The thrust of the paper is to relate the axioms to the kernel architecture and indicate that this opens a way of discussing some first-person issues: tests for consciousness, animal consciousness and Higher Order Thought. (shrink)

In list-method directed forgetting, reexposure to forgotten List 1 items has been shown to reduce directed forgetting. proposed that reexposure to a few List 1 items only during a direct test of memory reinstates the entire List 1 episode. In the present experiments, part-list reexposure in the context of indirect as well as direct memory tests reduced directed forgetting. Directed forgetting was reduced when 50% or more of the items were reexposed, and was intact when only 25% were reexposed. Furthermore, (...) part-list reexposure appeared to reinstate only reexposed items-not the entire List 1 episode. (shrink)

Can we make progress exploring consciousness? Or is it forever beyond human reach? In science we never know the ultimate outcome of the journey. We can only take whatever steps our current knowledge affords. This paper explores today's evidence from the viewpoint of Global Workspace theory. First, we ask what kind of evidence has the most direct bearing on the question. The answer given here is ‘contrastive analysis’ -- a set of paired comparisons between similar conscious and unconscious processes. This (...) body of evidence is already quite large, and constrains any possible theory . Because it involves both conscious and unconscious events, it deals directly with our own subjective experience, as anyone can tell by trying the demonstrations in this article. (shrink)

The world of our experience consists at all times of two parts, an objective and a subjective part . . . The objective part is the sum total of whatsoever at any given time we may be thinking of, the subjective part is the inner 'state' in which the thinking comes to pass.

Conscious experience is one of the most difficult and thorny problems in psychological science. Its study has been neglected for many years, either because it was thought to be too difficult, or because the relevant evidence was thought to be poor. Bernard Baars suggests a way to specify empirical constraints on a theory of consciousness by contrasting well-established conscious phenomena - such as stimulus representations known to be attended, perceptual, and informative - with closely comparable unconscious ones - such as (...) stimulus representations known to be preperceptual, unattended, or habituated. Adducing data to show that consciousness is associated with a kind of global workplace in the nervous system, and that several brain structures are known to behave in accordance with his theory, Baars helps to clarify many difficult problems. (shrink)

At this instant you, the reader, are conscious of some aspects of the act of reading --- the color and texture of THIS PAGE, and perhaps the inner sound of THESE WORDS. But you are probably not aware of the touch of your chair at this instant; nor of a certain background taste in your mouth, nor that monotonous background noise, the soft sound of music, or the complex syntactic processes needed to understand THIS PHRASE; nor are you now aware (...) of your feelings about a friend, the fleeting events of several seconds ago, or the multiple meanings of ambiguous words, as in THIS CASE. Even though you are not currently conscious of them, there is good of evidence that such unconscious events are actively processed in your brain, every moment you are awake. When we try to understand conscious experience we aim to explain the differences between these two conditions: between the events in your nervous system that you can report, act upon, distinguish, and acknowledge as your own, and a great multitude of sophisticated and intelligent processes which are unconscious, and do not allow these operations. (shrink)

Conscious perception, like the sight of a coffee cup, seems to involve the brain identifying a stimulus. But conscious input activates more brain regions than are needed to identify coffee cups and faces. It spreads beyond sensory cortex to frontoparietal association areas, which do not serve stimulus identification as such. What is the role of those regions? Parietal cortex support the ‘first person perspective’ on the visual world, unconsciously framing the visual object stream. Some prefrontal areas select and interpret conscious (...) events for executive control. Such functions can be viewed as properties of the subject, rather than the object, of experience – the ‘observing self’ that appears to be needed to maintain the conscious state. (shrink)

For many people, consciousness is one of the defining characteristics of mental states. Thus, it is quite surprising that consciousness has, until quite recently, had very little role to play in the cognitive sciences. Three very popular multi-authored overviews of cognitive science, Stillings et al. [33], Posner [26], and Osherson et al. [25], do not have a single reference to consciousness in their indexes. One reason this seems surprising is that the cognitive revolution was, in large part, a repudiation of (...) behaviorism's proscription against appealing to inner mental events. When researchers turned to consider inner mental events, one might have expected them to turn to conscious states of mind. But in fact the appeals were to postulated inner events of information processing. The model for many researchers of such information processing is the kind of transformation of symbolic structures that occurs in a digital computer. By positing procedures for performing such transformation of incoming information, cognitive scientists could hope to account for the performance of cognitive agents. Artificial intelligence, as a central discipline of cognitive science, has seemed to impose some of the toughest tests on the ability to develop information processing accounts of cognition: it required its researchers to develop running programs whose performance one could compare with that of our usual standard for cognitive agents, human beings. As a result of this focus, for AI researchers to succeed, at least in their primary task, they did not need to attend to consciousness; they simply had to design programs that behaved appropriately (no small task in itself!). This is not to say that conscious was totally ignored by artificial intelligence researchers. Some aspect of our conscious experience seemed critical to the success of any information processing model. For example, conscious agents exhibit selective attention. Some information received through their senses is attended to; much else is ignored.. (shrink)

Purpose: Constructivism postulates that the perceived reality is a complex construct formed during development. Depending on the particular school, these inner constructs take on different forms and structures and affect cognition in different ways. The purpose of this article is to address the questions of how and, even more importantly, why we form such inner constructs. Approach: This article proposes that brain development is controlled by an inherent anticipatory drive, which biases learning towards the formation of forward predictive structures and (...) inverse goal-oriented control structures. This drive, in combination with increasingly complex environmental interactions during cognitive development, enforces the structuring of our conscious self, which is embedded in a constructed inner reality. Essentially, the following questions are addressed: Which basic mechanisms lead us to the construction of inner realities? How are these emergent inner realities structured? How is the self represented within the inner realities? And consequently, which cognitive structures constitute the media for conscious thought and selfconsciousness? Findings: Due to the anticipatory drive, representations in the brain shape themselves predominantly purposefully or intentionally. Taking a developmental, evolutionary perspective, we show how the brain is forced to develop progressively complex and abstract representations of the self embedded in the constructed inner realities. These self representations can evoke different stages of self-consciousness. Implications: The anticipatory drive shapes brain structures and cognition during the development of progressively more complex, competent, and flexible goal-oriented bodyenvironment interactions. Self-consciousness develops because increasingly abstract, individualizing self representations are necessary to realize these progressively more challenging environmental interactions. (shrink)

Treating consciousness as awareness or attention greatly underestimates it, ignoring the temporary levels of organization associated with higher intellectual function (syntax, planning, logic, music). The tasks that require consciousness tend to be the ones that demand a lot of resources. Routine tasks can be handled on the back burner but dealing with ambiguity, groping around offline, generating creative choices, and performing precision movements may temporarily require substantial allocations of neocortex. Here I will attempt to clarify the appropriate levels of explanation (...) (ranging from quantum aspects to association cortex dynamics) and then propose a specific mechanism (consciousness as the current winner of Darwinian copying competitions in cerebral cortex) that seems capable of encompassing the higher intellectual function aspects of consciousness as well as some of the attentional aspects. It includes features such as a coding space appropriate for analogies and a supervisory Darwinian process that can bias the operation of other Darwinian processes. (shrink)

Wegner and colleagues have offered an explanation of the sense of agency over one’s bodily actions. If the orthodox view is correct and there is a sense of agency deficit associated with delusions of alien control, then Wegner and colleagues’ model ought to extend to an explanation of this deficit. Data from intentional binding studies opens up the possibility that an abnormality in representing the timing of mental events leads to a violation of the principle of priority in those suffering (...) from delusions of alien control. However, the model ultimately fails as it is unable to accommodate action monitoring deficits associated with delusions of alien control, in particular the theory of mind deficiencies predicted by such accounts have not materialiszed. There are theory of mind problems associated with schizophrenia but they are not associated with delusions of alien control. Such accounts thereby fail to adequately explain delusions of alien control. (shrink)

The rubber hand illusion (RHI) is the experience of an artificial body part as being a real body part and the experience of touch coming from that artificial body part. An explanation of this illusion would take significant steps towards explaining the experience of embodiment in one’s own body. I present a new cognitive model to explain the RHI. I argue that the sense of embodiment arises when an on-line representation of the candidate body part is represented as matching an (...) off-line prototype representation of what one’s body is usually like. The cause of the sense of embodiment in the model body part only partially overlaps with the causes of proprioceptive drift, which commonly accompanies the RHI, and so is compatible with observed dissociations between the illusion and proprioceptive drift. The distinguishing features of this model are the off-line body representation, and the process of matching an on-line model to an off-line model, both of which are to be understood in terms of a conceptual space. -/- Key Words: Rubber Hand Illusion; RHI; Sense of Embodiment; Self Consciousness; Body Experience. (shrink)

And why is there a subjective component to experience?). It is easy to see that the separation between Weak and Strong Artificial Consciousness mirrors the separation between the easy problems and the hard problems of consciousness.

Cognitive developmental disorders cannot be properly understood without due attention to the developmental process, and we commend the authors’simulations in this regard. We note the contribution of these simulations to the nascent field of connectionist modeling of developmental disorders and outline a set of criteria for assessing individual models in the hope of furthering future modeling efforts.

Durgin's (2002) commentary on our article provides us with an opportunity to look more closely at the relationship between information processing and consciousness. In our article we contrasted the information processing approach to interpreting our data, with our own 'scientific' approach to consciousness. However, we should point out that, on our view, information processing as a methodology is not by itself in conflict with the scientific study of consciousness - indeed, we have adopted this very methodology in our experiments, which (...) we purport to use to investigate consciousness. Furthermore, Durgin's own review of the history of research on metacontrast (Lachter & Durgin, 1999) shows that some researchers investigating metacontrast also thought that they were in the business of evaluating the role of consciousness in accounting for their effects. Yet, there is no doubt that metacontrast research is a paradigm case of research generated from an information processing perspective. So, prima facie, investigating consciousness and using information processing methodology are compatible. (shrink)

Neurophysiological and psychological evidence require us to see perception, the ‘fabrication of experience’, as a process in time. Some of the elapsed time between the onset of stimulation and the appearance of a conscious image is accounted for by onsiderations of neural hardware. Cognitive science conventionally assumes that these structural factors are sufficient to account for the delay. However I argue in this paper that the human information processing system may interpose an additional strategic delay that allows for processes of (...) checking and editing the developing ‘sketch’ or ‘draft’, so that elements that might threaten an underlying self system can be massaged or deleted. This cognitive model parallels that which is found in the Buddhist Abhidhamma, and improves upon the traditional, canonical formulation. Mindfulness meditation can be seen as a process of ‘attentional retraining’, in which the strategic delay is reduced through practice, and self-related assumptions, which had previously been dissolved in or pre-supposed by conscious experience, become crystallized out and capable of being problematized. (shrink)

This volume takes the first step toward building the necessary local bridges.

A technique for the bilateral activation of neural nets that leads to a functional asymmetry of two simulated ''cerebral hemispheres'' is described. The simulation is designed to perform object recognition, while exhibiting characteristics typical of human consciousness-specifically, the unitary nature of conscious attention, together with a dual awareness corresponding to the ''nucleus'' and ''fringe'' described by William James (1890). Sensory neural nets self-organize on the basis of five sensory features. The system is then taught arbitrary symbolic labels for a small (...) number of similar stimuli. Finally, the trained network is exposed to nonverbal stimuli for object recognition, leading to Gaussian activation of the ''sensory'' maps-with a peak at the location most closely related to the features of the external stimulus. ''Verbal'' maps are activated most strongly at the labeled location that lies closest to the peak on homologous sensory maps. On the verbal maps activation is characterized by both excitatory and inhibitory Gaussians (a Mexican hat), the parameters of which are determined by the relative locations of the verbal labels. Mutual homotopic inhibition across the ''corpus callosum'' then produces functional cerebral asymmetries, i.e., complementary activation of homologous ''association'' and ''frontal'' maps within a common focus of attention-a nucleus in the left hemisphere and a fringe in the right hemisphere. An object is recognized as corresponding to a known label when the total activation of both hemispheres (nucleus plus fringe) is strongest for that label. The functional dualities of the cerebral hemispheres are discussed in light of the nucleus/fringe asymmetry. (shrink)

The notion of loop seems to be ubiquitous in the study of organisms, the human mind and symbolic systems. With the possible exception of quantum-mechanical approaches, the treatments of consciousness we are acquainted with crucially appeal to the concept of loop. The uses of loops in this context fall within two broad classes. In the first one, loops are used to express the control of the organism’s interaction with the environment; in the second one, they are used to express self-reference. (...) Both classes are tied with investigations which aim at accounting for symbolic capabilities, and ultimately for subjectivity. Neurophysiological research detects loops in the animal nervous system since its very inception (e.g., all the work on the reflex arc). Recently, Gray proposed a model purporting to explain the mechanism supporting the contents of consciousness in the human CNS, in ways that are practically indistinguishable from models formulated within the cybernetical point of view. Both types of models apply loops in strikingly similar ways. While there is no conclusive evidence that loops are necessary to support consciousness, they are nonetheless as good a candidate as today can be found for inclusion in the list of essential ingredients for subjectivity to arise. In the first two sections we discuss the above mentioned uses by means of significant examples. In the third section, we compare Gray’s recent model to MacKay’s early cybernetical model of a selfobserving system, in the setting of a broader discussion on loops for consciousness. (shrink)

The master-module theory of consciousness is considered in the light of experimental evidence that has emerged since the model was first published. It is found that these new results tend to strengthen the original hypothesis. It is also argued that the master module is involved in generation of the schemata previously postulated to be associated with consciousness . The recent discovery of attention-related activity in the thalamic intralaminar nuclei is taken to indicate that these structures constitute an important part of (...) the feedback loop which the theory conjectured to mediate thought. The theory is shown to lead to a remarkably simple rationalization of the cerebral cortex, and it offers explanations of attention, binocular rivalry and qualia. It also makes the surprising prediction that Broca's area might not exclusively serve speech. (shrink)

Recent conjectures regarding the nature and mechanism of consciousness are extended to include the contribution of the cerebellum. The role of this brain structure appears to be a rather sophisticated form of prediction, as exemplified by certain dynamical capabilities of the visual system, and by the difficulty of self-administered tickling. The pars intermedia of the cerebellum is perceived as a direct feedback device, functioning in parallel to the primary neuronal circuit involved in consciousness; this leads to the suggestion that it (...) serves as a tutor for the putative master node, the latter governing the collective movements of all the body's muscles. The cerebellar hemispheres are believed to act as an internal feedback device, and to be more directly coupled to the master node; they are seen as serving plenisentient unconsciousness. The possible importance of muscular spindles for the generation of qualia is discussed, as are the significance of the frontal lobes, the basal ganglia and the limbic system for the content of consciousness. Finally, the stages through which infant consciousness gradually acquires its sophistication are tentatively identified. (shrink)

This paper investigates the role of a pre-existing body-model that is an enabling constraint for the incorporation of objects into the body. This body-model is also a basis for the distinction between body extensions (e.g., in the case of tool-use) and incorporation (e.g., in the case of successful prosthesis use). It is argued that, in the case of incorporation, changes in the sense of body-ownership involve a reorganization of the body-model, whereas extension of the body with tools does not involve (...) changes in the sense of body-ownership. (shrink)