According to representationalism, phenomenal character supervenes on representational content. According to first-person reports, blindsighters have no phenomenal character in the scotoma, even though their abilities suggest that they have conscious visual representations in the scotoma. The traditional representationalist response is that the representations in the scotoma are either non-conscious or non-visual. Drawing on empirical work, I consider the interpretation that blindsighters are unable to represent—and thus lack the phenomenal character of—luminance in the scotoma. However, they maintain the capacity to represent (...) other visible properties in the scotoma, and thus retain the luminance-lacking phenomenal character of these properties. (shrink)

This paper aims to clarify the relationship between consciousness and attention through theoretical considerations about evolution. Specifically, we will argue that the empirical findings on attention and the basic considerations concerning the evolution of the different forms of attention demonstrate that consciousness and attention must be dissociated regardless of which definition of these terms one uses. To the best of our knowledge, no extant view on the relationship between consciousness and attention has this advantage. Because of this characteristic, this paper (...) presents a principled and neutral way to settle debates concerning the relationship between consciousness and attention, without falling into disputes about the meaning of these terms. A decisive conclusion of this approach is that extreme views on the relationship between consciousness and attention must be rejected, including identity and full dissociation views. There is an overlap between the two within conscious attention, but developing a full understanding of this mechanism requires further empirical investigations. (shrink)

There are two distinct but related threads in this article. The first is methodological and is aimed at exploring the relative merits and faults of different operational definitions of consciousness. The second is conceptual and is aimed at understanding the prior commitments regarding the nature of conscious content that motivate these positions. I consider two distinct operationalizations: one defines consciousness in terms of dichotomous subjective reports, the other in terms of graded subjective reports. I ultimately argue that both approaches are (...) inadequate and that a third alternative that involves integration of subjective report and task performance should be adopted. (shrink)

This is a bibliography of books and articles on consciousness in philosophy, cognitive science, and neuroscience over the last 30 years. There are three main sections, devoted to monographs, edited collections of papers, and articles. The first two of these sections are each divided into three subsections containing books in each of the main areas of research. The third section is divided into 12 subsections, with 10 subject headings for philosophical articles along with two additional subsections for articles in cognitive (...) science and neuroscience. Of course the division is somewhat arbitrary, but I hope that it makes the bibliography easier to use. This bibliography has first been compiled by Thomas Metzinger and David Chalmers to appear in print in two philosophical anthologies on conscious experience . From 1995 onwards it has been continuously updated by Thomas Metzinger, and now is freely available as a PDF-, RTF-, or HTML-file. This bibliography mainly attempts to cover the Anglo-Saxon and German debates, in a non-annotated, fully formatted way that makes it easy to "cut and paste" from the original file. To a certain degree this bibliography also contains items in other languages than English and German - all submissions in other languages are welcome. Last update of current version: July 13th, 2001. (shrink)

Large changes in a scene often become difficult to notice if made during an eye movement, image flicker, movie cut, or other such disturbance. It is argued here that this _change blindness_ can serve as a useful tool to explore various aspects of vision. This argument centers around the proposal that focused attention is needed for the explicit perception of change. Given this, the study of change perception can provide a useful way to determine the nature of visual attention, and (...) to cast new light on the way that it is?and is not?involved in visual perception. To illustrate the power of this approach, this paper surveys its use in exploring three different aspects of vision. The first concerns the general nature of _seeing_. To explain why change blindness can be easily induced in experiments but apparently not in everyday life, it is proposed that perception involves a _virtual representation_, where object representations do not accumulate, but are formed as needed. An architecture containing both attentional and nonattentional streams is proposed as a way to implement this scheme. The second aspect concerns the ability of observers to detect change even when they have no visual experience of it. This _sensing_ is found to take on at least two forms: detection without visual experience (but still with conscious awareness), and detection without any awareness at all. It is proposed that these are both due to the operation of a nonattentional visual stream. The final aspect considered is the nature of visual attention itself?the mechanisms involved when _scrutinizing_ items. Experiments using controlled stimuli show the existence of various limits on visual search for change. It is shown that these limits provide a powerful means to map out the attentional mechanisms involved. (shrink)

Various neurophysiological experiments have revealed remarkable correlations between cortical neuronal activity and subjective experiences. However, the mere presence of neuronal electrical activity does not appear to be sufficient to produce these experiences. It has been suggested that the explanation for the neural basis of consciousness might lie in understanding the reason that some types of neuronal activity possess subjective correlates and others do not. Here I propose and develop the idea that this difference may be caused by the existence of (...) an elementary nonarbitrary linkage between temporal or spatiotemporal patterns of neuronal activity and their subjective attributes. I also show how cortical neural circuits capable of generating experience-coding patterns could emerge during evolution and brain development, due to the presence of spontaneous stochastic neuronal activity and activity-dependent synaptic plasticity. This hypothesis leads to several testable predictions, principal among which is the idea that the neural correlates of consciousness are essentially innate and universal. (shrink)

The duration of “now” is shown to be important not only for an understanding of how conscious beings sense duration, but also for the validity of the phenomenological enterprise as Husserl conceived it. If “now” is too short, experiences can not be described before they become memories, which can be considered to be transcendent rather than immanent phenomena and therefore inadmissible as phenomenological data. Evidence concerning (a) the objective duration of sensations in various sensory modalities, (b) the time necessary for (...) sensations to enter consciousness and (c) the variability in the subjective sense of time's passing under different conditions is used to conclude that the duration of “now” can actually vary under normal conditions from about 10 ms to several seconds and in extreme cases up to several hours. Thus the immanent moment can be long enough to encompass a report of the contents of consciousness, making phenomenology a viable project. A further speculation from the evidence described is that consciousness takes discrete samples of the external world, at a rate inversely proportional to the duration of the “now” moment. (shrink)

Local Recurrency Theory (LR) holds that recurrent loops of neural activity localized to the visual cortex are necessary and sufficient for visual consciousness (if certain background conditions obtain). LR’s popularity has recently waned in favor of theories holding that higher-level types of processing are necessary for consciousness (for example, the Global Neuronal Workspace Theory and Higher-order Theory). This has been in part because of empirical evidence thought to disconfirm LR. However, these competing theories now face challenges of their own, often (...) coming in the form of evidence showing that higher-level brain areas (that is, in the prefrontal cortex) are probably not essential for consciousness. Given growing challenges to LR's competitors, it would be timely to re-assess the prospects for LR. This article carries out such an investigation, first laying out the theory precisely, then going on to survey the evidence presented against it. What will be found is that none of the evidence necessarily undermines LR, but instead just fosters its theoretical enrichment. The overall conclusion: LR remains among our most promising neuroscientific theories of visual consciousness. (shrink)

Cognitive Science, Volume 46, Issue 10, October 2022.

This editorial introduces the Journal of Consciousness Studies special issue on "Animal Consciousness". The 15 contributors and co-editors answer the question "How should we study animal consciousness scientifically?" in 500 words or fewer.

Post-decision wagering has been proposed as a method of demonstrating that perception can occur without conscious awareness. When wagering is independent from above-chance performance there is evidence of a lack of awareness of the correctness of the first-order discriminations. However, there are reasons to believe that the contingency analysis conducted by Persaud and colleagues failed to measure “the zero accuracy-wagering criterion”. The author shows that a Pearson chi-square test employed by Persaud and colleagues is unable to accommodate the hypothesis of (...) partial independence between accuracy and advantageous wagering. On the contrary, the problem of “the zero accuracy-wagering criterion” is best conducted with log-linear models. Moreover, log-linear analysis suggests that absence of advantageous wagering is not sufficient evidence for a lack of conscious awareness. In the case of the blindsight study, there was compelling evidence that the patient GY was partially aware of having information about the correctness of his decisions. (shrink)

People’s awareness of tactile stimuli has been investigated in far less detail than their awareness of stimuli in other sensory modalities. In an attempt to fill this gap, we provide an overview of studies that are pertinent to the topic of tactile consciousness. We discuss the results of research that has investigated phenomena such as “change blindness”, phantom limb sensations, and numerosity judgments in tactile perception, together with the results obtained from the study of patients affected by deficits that can (...) adversely affect tactile perception such as neglect, extinction, and numbsense. The similarities as well as some of the important differences that have emerged when visual and tactile conscious information processing have been compared using similar experimental procedures are highlighted. We suggest that conscious information processing in the tactile modality cannot be separated completely from the more general processing of spatial information in the brain. Finally, the importance of considering tactile consciousness within the larger framework of multisensory information processing is also discussed. (shrink)

Dijkerman & de Haan (D&dH) propose a somatosensory perceptual pathway that informs a consciously accessible body image, and an action pathway that provides information to a body schema, which is not consciously accessible. We argue that the body schema may become accessible to consciousness in some circumstances, possibly resulting from cross talk, but that this may be detrimental to skilled movement production.

Evidence for motion extrapolation at motion offset is scarce. In contrast, there is abundant evidence that subjects mentally extrapolate the future trajectory of weak motion signals at motion offset. Further, pointing movements overshoot at motion offset. We believe that mental and sensorimotor extrapolation is sufficient to solve the problem of perceptual latencies. Both present the advantage of being much more flexible than motion extrapolation.

Visual information follows at least two branches in the human nervous system, following a common input stage: a cognitive ''what'' branch governs perception and experience, while a sensorimotor ''how'' branch handles visually guided behavior though its outputs are unconscious. The sensorimotor system is probed with an isomorphic task, requiring a 1:1 relationship between target position and motor response. The cognitive system, in contrast, is probed with a forced qualitative decision, expressed verbally, about the location of a target. Normally, the cognitive (...) system is influenced by context-induced illusions of visual direction, while the sensorimotor system is not. Here, we inquire whether the process of making a spatially based decision is critical in forcing subjects to use the information in the cognitive system for spatial tasks. Subjects hear a tone that determines whether they jab an ''X'' or an ''O'' with the forefinger. Despite making a decision about which target to contact, the jab is not influenced by the position of a surrounding frame, indicating that choice can be handled within the context-insensitive sensorimotor system. (shrink)

The question of whether blindsight is a form of unconscious perception continues to spark fierce debate in philosophy and psychology. One side of the debate holds that while the visual information categorized in blindsight is not access-conscious, it is nonetheless a form of perception, albeit a form of unconscious perception. The opposition, by contrast, holds that blindsight is just a form of degraded conscious perception that makes the categorized information harder to access because it is degraded. In this chapter, we (...) address the opposition’s arguments for thinking that blindsight is a form of degraded conscious vision and then argue that the residual awareness found in blindsight is a form of non-perceptual awareness. To back this claim, we examine the residual visual abilities to detect and discriminate colour found in some blindsight patients and show that residual consciousness in blindsight is indirect and lacks the phenomenal character characteristic of conscious vision. (shrink)

Relationalism claims that the phenomenal character of perception is constituted by the obtaining of a non-representational psychological relation to mind-independent objects. Although relationalism provides what seems to be the most straightforward and intuitive account of how experience strikes us introspectively, it is very often believed that the argument from hallucination shows that the view is untenable. The aim of this thesis is to defend relationalism against the argument from hallucination. The argument claims that the phenomenal character of hallucination and perception (...) deserves the same account, and that relationalism cannot be true for hallucinations, therefore relationalism must be rejected. This argument relies on the Indiscriminability Principle, the claim that two experiences that are introspectively indiscriminable from each other have the same phenomenal character. Before assessing the plausibility of this principle, I first consider and dismiss versions of the argument which wouldn’t depend on IND. Although widely accepted, no satisfactory support for IND has been presented yet. In this thesis I argue that defending IND requires that we understand the notion of ‘indiscriminability’ employed in IND in an impersonal sense. I then identify what underwrites IND: the intuition that, in virtue of its superficiality, the nature of a phenomenal character must be accessible through introspection, together with the claim that it is not possible to deny IND without denying the superficiality of phenomenal characters too. I argue that the relationalist can deny IND while preserving the superficiality of phenomenal characters. This can be done by adopting a negative view of hallucination and an account of introspection whereby the phenomenal character doesn’t exist independently of one’s introspective awareness of it and where having introspective access to our experience depends on our perceptual access to the world. (shrink)

Libertarians about free will sometimes argue for their position on the grounds that our phenomenology of action is such that determinism would need to be false for it to be veridical. Many, however, have thought that it would be impossible for us to have an experience that is in contradiction with determinism, since this would require us to have perceptual experience of metaphysical facts. In this paper I show how the libertarian claim is possible. In particular, if experience depicts the (...) world such that there is more than one physically possible future, then determinism would need to be false for that experience to be veridical. I show that we have experiences, or perceptual episodes, of this kind on the basis of recent work in the study of perception. Theorists in this area have argued that we have vision-for-action, and that what we visually perceive are not just objects but also possibilities for action. If we experience that it is possible that we ϕ, then we also experience that it is possible that we not ϕ. Furthermore, we probably experience more than one possibility for action at any one moment. I argue that these are physical possibilities, and therefore that we experience the world such that there is more than one physically possible future. So the libertarian claim about the semantics of agential phenomenology is highly plausible, even if this does not entail libertarianism. (shrink)

Accurate perception of moving objects would be useful; accurate visually guided action is crucial. Visual motion across the scene influences perceived object location and the trajectory of reaching movements to objects. In this commentary, I propose that the visual system assigns the position of any object based on the predominant motion present in the scene, and that this is used to guide reaching movements to compensate for delays in visuomotor processing.

The parietal cortex is divided into two major functional regions: the anterior parietal cortex that includes primary somatosensory cortex, and the posterior parietal cortex (PPC) that includes the rest of the parietal lobe. The PPC contains multiple representations of space. In Dijkerman & de Haan's (D&dH's) model, higher spatial representations are separate from PPC functions. This model should be developed further so that the functions of the somatosensory system are integrated with specific functions within the PPC and higher spatial representations. (...) Through this further specification of the model, one can make better predictions regarding functional interactions between somatosensory and visual systems. (shrink)

The phenomenon of consciousness has received through the centuries a profusion of interpretations, engaging researchers across many disciplines. Nevertheless, consensus still floats at large. The aim of the present work is therefore twofold. Through the review of a selected number of existing proposals, it will first be considered the extents of their reciprocal compatibility, tentatively shaping an integrated, theoretical profile of consciousness. A new theory, the Endogenous Feedback Network will consequently be introduced which, besides being able to accommodate the main (...) tenets of the reviewed theories, appears able to compensate for the explanatory gaps they leave behind. The EFN proposes consciousness as the phenomenon emerging from a distinct neural network broadcasting the changes associated to mental activations across the brain. It additionally argues for the need to include a 5th element to Ned Block’s taxonomy that is, non-cognitive consciousness. (shrink)

The functions of the somatosensory system are multiple. We use tactile input to localize and experience the various qualities of touch, and proprioceptive information to determine the position of different parts of the body with respect to each other, which provides fundamental information for action. Further, tactile exploration of the characteristics of external objects can result in conscious perceptual experience and stimulus or object recognition. Neuroanatomical studies suggest parallel processing as well as serial processing within the cerebral somatosensory system that (...) reflect these separate functions, with one processing stream terminating in the posterior parietal cortex (PPC), and the other terminating in the insula. We suggest that, analogously to the organisation of the visual system, somatosensory processing for the guidance of action can be dissociated from the processing that leads to perception and memory. In addition, we find a second division between tactile information processing about external targets in service of object recognition and tactile information processing related to the body itself. We suggest the posterior parietal cortex subserves both perception and action, whereas the insula principally subserves perceptual recognition and learning. (shrink)

I propose and defend the Allocentric-Egocentric Interface Theory of Con- sciousness. Mental processes form a hierarchy of mental representations with maxi- mally egocentric (self-centered) representations at the bottom and maximally allocentric (other-centered) representations at the top. Phenomenally conscious states are states that are relatively intermediate in this hierarchy. More speci.

Cortical color blindness, or cerebral achromatopsia, has been likened by some authors to ''blindsight'' for color or an instance of ''covert'' processing of color. Recently, it has been shown that, although such patients are unable to identify or discriminate hue differences, they nevertheless show a striking ability to process wavelength differences, which can result in preserved sensitivity to chromatic contrast and motion in equiluminant displays. Moreover, visually evoked cortical potentials can still be elicited in response to chromatic stimuli. We suggest (...) that these demonstrations reveal intact residual processes rather than the operation of covert processes, where proficient performance is accompanied by a denial of phenomenal awareness. We sought evidence for such covert processes by conducting appropriate tests on achromatopsic subject M.S. An ''indirect'' test entailing measurement of reaction times for letter identification failed to reveal covert color processes. In contrast, in a forced choice oddity task for color, M.S. was unable to verbally indicate the position of the different color, but was surprisingly adept at making an appropriate eye movement to its location. This ''direct'' test thus revealed the possible covert use of chromatic differences. (shrink)

Since Freud and his co-author Breuer spoke of dissociation in 1895, a scientific paradigm was painstakingly established in the field of unconscious cognition. This is the dissociation paradigm. However, recent critical analysis of the many and various reported dissociations reveals their blurred, or unveridical, character. Moreover, we remain ignorant with respect to the ways cognitive phenomena transition from consciousness to an unconscious mode. This hinders us from filling in the puzzle of the unified mind. We conclude that we have reached (...) a Kuhnian crisis in the field of unconscious cognition, and we predict that new models, incorporating partly the relevant findings of the dissociation paradigm—but also of dynamic psychology—, will soon be established. We further predict that some of these models will be largely based on the pairs representation–process and analog–digital. (shrink)

This commentary is a plea to re-read after five years one, as it seems, almost forgotten book which has nevertheless clearly influenced the development of empirical approaches to consciousness. The book provides an illuminating look at the early period to the modern revival of consciousness research. Its subtitle 'Psychological and Philosophical Essays' describes the book's range precisely. Early attempts to disect the mystery of consciousness and many themes that are still preoccupying modern consciousness research are covered. While some areas of (...) research have been progressed, theoretical views have not changed dramatically, and this book still seems a good guide to embark on a mysterious journey when exploring consciousness. (shrink)