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 by the explanations it allows. (shrink)

_Stream of Consciousness_ is about the phenomenology of conscious experience. Barry Dainton shows us that stream of consciousness is not a mosaic of discrete fragments of experience, but rather an interconnected flowing whole. Through a deep probing into the nature of awareness, introspection, phenomenal space and time consciousness, Dainton offers a truly original understanding of the nature of consciousness.

One of the most important issues concerning the foundations ofconscious perception centerson thequestion of whether perceptual consciousness is rich or sparse. The overflow argument uses a form of ‘iconic memory’ toarguethatperceptual consciousnessisricher (i.e.,has a higher capacity) than cognitive access: when observing a complex scene we are conscious of more than we can report or think about. Recently, the overflow argumenthas been challenged both empirically and conceptually. This paper reviews the controversy, arguing that proponents of sparse perception are committed to the (...) postulation of (i) a peculiar kind of generic conscious representation that has no independent rationale and (ii) an unmotivated form of unconscious representation that in some cases conflicts with what we know about unconscious representation. (shrink)

_Behavioral and Brain Sciences_ , 15, 183-247, 1992. Reprinted in _The Philosopher's Annual_ , Grim, Mar and Williams, eds., vol. XV-1992, 1994, pp. 23-68; Noel Sheehy and Tony Chapman, eds., _Cognitive Science_ , Vol. I, Elgar, 1995, pp.210-274.

Amidst the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of those dissenting results. On the basis of a minimal neuro-computational model, the global neuronal workspace hypothesis, we propose a (...) taxonomy which distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with a sudden surge of parieto-frontal activity causing top-down amplification. (shrink)

The question I want to explore is whether experience supports an antireductionist ontology of time, that is, whether we should take it to support an ontology that includes a primitive, monadic property of nowness responsible for the special feel of events in the present, and a relation of passage that events instantiate in virtue of literally passing from the future, to the present, and then into the past.

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In ordinary conscious experience, consciousness of time seems to be ubiquitous. For example, we seem to be directly aware of change, movement, and succession across brief temporal intervals. How is this possible? Many different models of temporal consciousness have been proposed. Some philosophers have argued that consciousness is confined to a momentary interval and that we are not in fact directly aware of change. Others have argued that although consciousness itself is momentary, we are nevertheless conscious of change. Still others (...) have argued that consciousness is itself extended in time. In this entry, the motivations and merits of these and other positions will be expounded and assessed. (shrink)

Advances in neuroscience implicate reentrant signaling as the predominant form of communication between brain areas. This principle was used in a series of masking experiments that defy explanation by feed-forward theories. The masking occurs when a brief display of target plus mask is continued with the mask alone. Two masking processes were found: an early process affected by physical factors such as adapting luminance and a later process affected by attentional factors such as set size. This later process is called (...) masking by object substitution, because it occurs whenever there is a mismatch between the reentrant visual representation and the ongoing lower level activity. Iterative reentrant processing was formalized in a computational model that provides an excellent fit to the data. The model provides a more comprehensive account of all forms of visual masking than do the long-held feed-forward views based on inhibitory contour interactions. (shrink)

Variants of the slogan that a succession of experiences does not amount to an experience of succession are commonplace in the philosophical literature on temporal experience. I distinguish three quite different arguments that might be captured using this slogan: the individuation argument, the unity argument, and the causal argument. Versions of the unity and the causal argument are often invoked in support of a particular view of the nature of temporal experience sometimes called intentionalism, and against a rival view sometimes (...) called extensionalism. I examine these arguments in light of the individuation argument. In particular, I show that the individuation argument is, at least prima facie, neutral between those two views of temporal experience; and once the individuation argument is in place, the unity and causal argument also lose their force against extensionalism. (shrink)

How must experience of time be structured in time? In particular, does the following principle, which I will call inheritance, hold: for any temporal property apparently presented in perceptual experience, experience itself has that same temporal property. For instance, if I hear Paul McCartney singing ‘Hey Jude’, must my auditory experience of the ‘Hey’ itself precede my auditory experience of the ‘Jude’, or can the temporal order of these experiences come apart from the order the words are experienced as having? (...) A number of recent authors (Phillips Experience and Time, ‘The Temporal Structure of Experience’, Soteriou ‘Perceiving Events’, Hoerl ‘“A Succession of Feelings, in and of Itself, is Not a Feeling of Succession”’, Rashbrook) claim, to paraphrase Martin (399), that inheritance best characterises how our temporal experience seems to initial reflective intuition. For this reason, Phillips takes the principle to form part of our naïve view of temporal experience. An opposing group of theorists object that inheritance is subject to empirical counter-example. This article surveys such challenges. Section 2 considers Grush's case against inheritance based on postdiction. Section 3 examines Watzl's anti-inheritance argument based on silencing effects. Finally, Section 4 explores a number of alleged counter-examples proposed by Lee (‘Temporal Experience and the Temporal Structure of Experience’). Section 1 provides essential background to the debate. (shrink)

The visual brain consists of several parallel, functionally specialized processing systems, each having several stages (nodes) which terminate their tasks at different times; consequently, simultaneously presented attributes are perceived at the same time if processed at the same node and at different times if processed by different nodes. Clinical evidence shows that these processing systems can act fairly autonomously. Damage restricted to one system compromises specifically the perception of the attribute that that system is specialized for; damage to a given (...) node of a processing system that leaves earlier nodes intact results in a degraded perceptual capacity for the relevant attribute, which is directly related to the physiological capacities of the cells left intact by the damage. By contrast, a system that is spared when all others are damaged can function more or less normally. Moreover, internally created visual percepts-illusions, afterimages, imagery, and hallucinations-activate specifically the nodes specialized for the attribute perceived. Finally, anatomical evidence shows that there is no final integrator station in the brain, one which receives input from all visual areas; instead, each node has multiple outputs and no node is recipient only. Taken together, the above evidence leads us to propose that each node of a processing-perceptual system creates its own microconsciousness. We propose that, if any binding occurs to give us our integrated image of the visual world, it must be a binding between microconsciousnesses generated at different nodes. Since any two microconsciousnesses generated at any two nodes can be bound together, perceptual integration is not hierarchical, but parallel and postconscious. By contrast, the neural machinery conferring properties on those cells whose activity has a conscious correlate is hierarchical, and we refer to it as generative binding, to distinguish it from the binding that might occur between the microconsciousnesses. (shrink)

The question of whether time is its own best representation is explored. Though there is theoretical debate between proponents of internal models and embedded cognition proponents (e.g. Brooks R 1991 Artificial Intelligence 47 139–59) concerning whether the world is its own best model, proponents of internal models are often content to let time be its own best representation. This happens via the time update of the model that simply allows the model’s state to evolve along with the state of the (...) modeled domain. I argue that this is neither necessary nor advisable. I show that this is not necessary by describing how internal modeling approaches can be generalized to schemes that explicitly represent time by maintaining trajectory estimates rather than state estimates. Though there are a variety of ways this could be done, I illustrate the proposal with a scheme that combines filtering, smoothing and prediction to maintain an estimate of the modeled domain’s trajectory over time. I show that letting time be its own representation is not advisable by showing how trajectory estimation schemes can provide accounts of temporal illusions, such as apparent motion, that pose serious difficulties for any scheme that lets time be its own representation. (shrink)

Can we directly experience change? Although some philosophers have denied it, the phenomenological evidence is unambiguous: we can, and do. But how is this possible? What structures or features of consciousness render such experience possible? A variety of very different answers to this question have been proposed, answers which have very different implications for the nature of consciousness itself. In this brief survey no attempt is made to engage with the often complex (and sometimes obscure) literature on this topic. Instead, (...) a largely schematic examination of the main options is conducted, with a view to determining the most promising avenues for further investigation. (shrink)

The aim in this paper is to focus on one of the proposals about successful perception that has led its adherents to advance some kind of disjunctive account of experience. The proposal is that we should understand the conscious sensory experience involved in successful perception in relational terms. I first try to clarify what the commitments of the view are, and where disagreements with competing views may lie. I then suggest that there are considerations relating to the conscious character of (...) our perception of events that speak in its favour. (shrink)

In apparent motion experiments, participants are presented with what is in fact a succession of two brief stationary stimuli at two different locations, but they report an impression of movement. Philosophers have recently debated whether apparent motion provides evidence in favour of a particular account of the nature of temporal experience. I argue that the existing discussion in this area is premised on a mistaken view of the phenomenology of apparent motion and, as a result, the space of possible philosophical (...) positions has not yet been fully explored. In particular, I argue that the existence of apparent motion is compatible with an account of the nature of temporal experience that involves a version of direct realism. In doing so, I also argue against two other claims often made about apparent motion, viz. that apparent motion is the psychological phenomenon that underlies motion experience in the cinema, and that apparent motion is subjectively indistinguishable from real motion. (shrink)

It has often been assumed that when we use vision to become aware of an object or event in our surroundings, this must be accompanied by a corresponding visual experience (i.e., seeing). The studies reported here show that this assumption is incorrect. When observers view a sequence of displays alternating between an image of a scene and the same image changed in some way, they often feel (or sense) the change even though they have no visual experience of it. The (...) subjective difference between sensing and seeing is mirrored in several behavioral differences, suggesting that these are two distinct modes of conscious visual perception. (shrink)

Nothing is more obvious than the fact that we are able to experience events in the world such a ball deflecting from the cross-bar of a goal. But what is the temporal relation between these two things, the event, and our experience of the event? One possibility is that the world progresses temporally through a sequence of instantaneous states – the striker’s foot in contact with the ball, then the ball between the striker and the goal, then the ball in (...) contact with the cross-bar, and so forth –, while the perceiver’s experience is likewise a sequence of experience states, each one of which corresponds to, or is experience of, a corresponding state of the world – for example, a perception of the foot in contact with the ball, followed by a perception of the ball in the air, following by a perception of the ball in contact with the cross-bar. This way of understanding the relationship between experience and the world is very natural, and nearly universal. However, it rests on two assumptions that can be brought into question. (shrink)

In timing perception studies, the timing of one event is usually manipulated relative to another, and participants are asked to judge if the two events were synchronous, or to judge which of the two events occurred first. Responses are analyzed to determine a measure of central tendency, which is taken as an estimate of the timing at which the two events are perceptually synchronous. When these estimates do not coincide with physical synchrony, it is often assumed that the sensory signals (...) are asynchronous, as though the transfer of information concerning one input has been accelerated or decelerated relative to the other. Here we show that, while this is a viable interpretation, it is equally plausible that such effects are driven by shifts in the criteria used to differentiate simultaneous from asynchronous inputs. Our analyses expose important ambiguities concerning the interpretation of simultaneity judgement data, which have hitherto been underappreciated. (shrink)

A key question in understanding visual awareness is whether any single cortical area is indispensable. In a transcranial magnetic stimulation experiment, we show that observers' awareness of activity in extrastriate area VS depends on the amount of activity in striate cortex (Vl). From the timing and pattern of effects, we infer that back-projections from extrastriate cortex influence information content in Vl, but it is Vl that determines whether that information reaches awareness.

It is argued that a subject who has an experience as of succession can have this experience at a time, or over a period of time, during which there occurs in him no succession of conscious mental states at all. Various metaphysical implications of this conclusion are explored. One premise of the main argument is that every experience is an experience as of succession. This implies that we cannot understand phenomenal temporality as a relation among experiences, but only as a (...) primitive feature of experience, or else as something analyzable into wholly non-phenomenal terms. (shrink)

A theoretical assumption of this chapter on time in mind is that people ought to take phenomenological descriptions of temporal experience at face value. The chapter begins with a brief review of Rick Grush's trajectory estimation model of temporal representation – the predictive inference model. It introduces the issues of whether temporal properties as they appear should be thought of as primary or secondary qualities. A constraint runs from the best science of the mind back to phenomenology that the best (...) phenomenological descriptions of experience cohere with the best science of the human mind. Grush's model bears a close resemblance to computational theories in neuroscience that take perception to consist in predictive inference. A section explains the relationship between the Orwellian interpretation of postdiction and the Husserlian view of temporal experience. The chapter also presents a discussion on “the time as its own representation view” (TOR) and supervenience thesis (SUP). (shrink)

This paper analyses explanations provided by current philosophical models of time consciousness. These models attempt to explain temporal experience by describing the mechanisms of time consciousness in experiential terms. I criticize this practice on two grounds; firstly, it relies upon folk notions that have no clear individuation conditions and secondly because it often merely names, but does not explain the phenomena.

Dennett and Kinsbourne ([1992]) argue that metacontrast backward visual masking provides a clear illustration that ‘there is really only a verbal difference’ between two versions of the Cartesian Theater model of the mind. This alleged lack of a distinction is both the crucial premise of their main argument against the Cartesian Theater and a motivator for accepting their own Multiple Drafts model. I argue that metacontrast reveals a difference between the two versions of the Cartesian Theater that meets criteria found (...) in (Dennett and Kinsbourne [1992]) for determining such a difference. This difference undermines the soundness of their argument against the Cartesian Theater, and exerts pressure on Dennett and Kinsbourne to offer a more detailed articulation of their model. 1. Introduction2. Brief Explanation of Metacontrast Backward Visual Masking3. The Stalinesque and Orwellian Models of Metacontrast 3.1. Criteria for determining a difference4. A Difference That Makes a Difference 4.1. Skeptical hypothesis objection5. Other Objections and Replies 5.1. Straw person objection5.2. Corroborative issues objection6. Conclusion. (shrink)

Event-related potential studies have attempted to discover the processes that underlie conscious visual perception by contrasting ERPs produced by stimuli that are consciously perceived with those that are not. Variability of the proposed ERP correlates of consciousness is considerable: the earliest proposed ERP correlate of consciousness coincides with sensory processes and the last one marks postperceptual processes. A negative difference wave called visual awareness negativity , typically observed around 200 ms after stimulus onset in occipitotemporal sites, gains strong support for (...) reflecting the processes that correlate with, and possibly enable, aware visual perception. Research suggests that the early parts of conscious processing can proceed independently of top-down attention, although top-down attention may modulate visual processing even before consciousness. Evidence implies that the contents of consciousness are provided by interactions in the ventral stream, but indispensable contributions from dorsal regions influence already low-level visual responses. (shrink)