Traditionally, philosophers have appealed to the phenomenological similarity between visual experience and visual imagery to support the hypothesis that there is significant overlap between the perceptual and imaginative domains. The current evidence, however, is inconclusive: while evidence from transcranial brain stimulation seems to support this conclusion, neurophysiological evidence from brain lesion studies (e.g., from patients with brain lesions resulting in a loss of mental imagery but not a corresponding loss of perception and vice versa) indicates that there are functional and (...) anatomical dissociations between mental imagery and perception. Assuming that the mental imagery and perception do not overlap, at least, to the extent traditionally assumed, then the question arises as to what exactly mental imagery is and whether it parallels perception by proceeding via several functionally distinct mechanisms. In this review, we argue that even though there may not be a shared mechanism underlying vision for perception and conscious imagery, there is an overlap between the mechanisms underlying vision for action and unconscious visual imagery. On the basis of these findings, we propose a modification of Kosslyn’s model of imagery that accommodates unconscious imagination and explore possible explanations of the quasi-pictorial phenomenology of conscious visual imagery in light of the fact that its underlying neural substrates and mechanisms typically are distinct from those of visual experience. (shrink)

Phillips argues that blindsight is due to response criterion artefacts under degraded conscious vision. His view provides alternative explanations for some studies, but may not work well when one considers several key findings in conjunction. Empirically, not all criterion effects are decidedly non-perceptual. Awareness is not completely abolished for some stimuli, in some patients. But in other cases, it was clearly impaired relative to the corresponding visual sensitivity. This relative dissociation is what makes blindsight so important and interesting.

Recently, it has been objected that naïve realism is inconsistent with an empirically well-supported claim that mental states of the same fundamental kind as ordinary conscious seeing can occur unconsciously (SFK). The main aim of this paper is to establish the following conditional claim: if SFK turns out to be true, the naïve realist can and should accommodate it into her theory. Regarding the antecedent of this conditional, I suggest that empirical evidence renders SFK plausible but not obvious. For it (...) is possible that what is currently advocated as unconscious perception of the stimulus is in fact momentaneous perceptual awareness (or residual perceptual awareness) of the stimulus making the subject prone to judge in some way rather than another, or to act in some way rather than another. As to the apodosis, I show that neither the core of naïve realism nor any of its main motivations is undermined if SFK is assumed. On the contrary, certain incentives for endorsing naïve realism become more tempting on this assumption. Since the main motivations for naïve realism retain force under SFK, intentionalism is neither compulsory nor the best available explanation of unconscious perception. (shrink)

Integration information theories posit that the integration of information is necessary and/or sufficient for consciousness. In this paper, we focus on three of the most prominent information integration theories: Information Integration Theory, Global Workspace Theory, and Attended Intermediate-Level Theory. We begin by explicating each theory and key concepts they utilize. We then argue that the current evidence indicates that the integration of information is neither necessary nor sufficient for consciousness. Unlike GWT and AIR, IIT maintains that conscious experience is both (...) necessary and sufficient for consciousness. We present empirical evidence indicating that simple features are experienced in the absence of feature integration and argue that it challenges IIT’s necessity claim. In addition, we challenge IIT’s sufficiency claim by presenting evidence from hemineglect cases and amodal completion indicating that contents may be integrated and yet fail to give rise to subjective experience. Moreover, we present empirical evidence from subjects with frontal lesions who are unable to carry out simple instructions and argue that they are irreconcilable with GWT. Lastly, we argue that empirical evidence indicating that patients with visual agnosia fail to identify objects they report being conscious of present a challenge to AIR’s necessity claim. (shrink)

Attention makes things look brighter and more colorful. In light of these effects, representationalist philosophers propose that attentive experiences represent more determinate color properties than inattentive experiences. Although this claim is appealing, we argue that it does not hold for one of our best conceptualizations of content determinacy, according to which an experience has more determinate contents if it represents a narrower range of values within the relevant dimension. We argue that our current empirical evidence fails to show that attention (...) has this kind of effect on color perception. We then offer an alternative, representationalist-friendly account of the attentional effects, as changes in vividness. (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)

A key contention of Klein & Barron (2016) is that consciousness does not depend on cortical structures. A critical appraisal suggests they have overestimated the strength of their evidence.

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)

Kant, Wittgenstein, and Husserl all held that visual awareness of objects requires visual awareness of the space in which the objects are located. There is a lively debate in the literature on spatial perception whether this view is undermined by the results of experiments on a Balint’s syndrome patient, known as RM. I argue that neither of two recent interpretations of these results is able to explain RM’s apparent ability to experience motion. I outline some ways in which each interpretation (...) may respond to this challenge, and suggest which way of meeting the challenge is preferable. I conclude that RM retains some awareness of the larger space surrounding the objects he sees. (shrink)

Back when researchers thought about the various forms that color vision could take, the focus was primarily on the retinal mechanisms. Since that time, research on human color vision has shifted from an interest in retinal mechanisms to cortical color processing. This has allowed color research to provide insight into questions that are not limited to early vision but extend to cognition. Direct cortical connections from higher-level areas to lower-level areas have been found throughout the brain. One of the classic (...) questions in cognitive science is whether perception is influenced, and if so to what extent, by cognition and whether a clear distinction can be drawn between perception and cognition. Since perception is seen as providing justification for our beliefs about properties in the external world, these questions also have metaphysical and epistemological significance. The aim of this paper is to highlight some of the areas where research on color perception can shed new light on questions in the cognitive sciences. A further aim of the paper is to raise some questions about color research that are in dire need of further reflection and investigation. (shrink)

In the past two decades a number of arguments have been given in favor of the possibility of phenomenal consciousness without attentional access, otherwise known as phenomenal overflow. This paper will show that the empirical data commonly cited in support of this thesis is, at best, ambiguous between two equally plausible interpretations, one of which does not posit phenomenology beyond attention. Next, after citing evidence for the feature-integration theory of attention, this paper will give an account of the relationship between (...) consciousness and attention that accounts for both the empirical data and our phenomenological intuitions without positing phenomenal consciousness beyond attention. Having undercut the motivations for accepting phenomenal overflow along with having given reasons to think that phenomenal overflow does not occur, I end with the tentative conclusion that attention is a necessary condition for phenomenal consciousness. -/- . (shrink)

Whether visual perceptual consciousness is gradable or dichotomous has been the subject of fierce debate in recent years. If perceptual consciousness is gradable, perceivers may have less than full access to—and thus be less than fully phenomenally aware of—perceptual information that is represented in working memory. This raises the question: In virtue of what can a subject be less than fully perceptually conscious? In this chapter, we provide an answer to this question, according to which inexact categorizations of visual input (...) may result in a representation of the visual information in working memory that is less than fully available to the perceiver, and of which the perceiver is therefore less than fully phenomenally aware. The latter proposal is a natural extension of a theory of perception we have proposed in previous works, namely, the template tuning theory (TTT). We argue that although TTT is compatible with both gradable and dichotomous conceptions of perceptual consciousness, the available empirical evidence favours a gradable conception of perceptual consciousness. (shrink)

Our experience seems to be populated by mind-independent objects. These very same objects are also experienced as offering the possibility of motor interactability. Thus, one may be tempted, prima facie, to consider these two experiences as always related. In this paper, I propose that this idea is not tenable, by invoking evidence from vision science and ophthalmology about a special case of blindness, stereoblindness. Stereoblind subjects cannot rely on stereopsis. Stereopsis is the visual mechanisms responsible for the experience of motor (...) interactability with objects. Nonetheless, as I argue, stereoblind subjects can experience objects as mind-independent (notwithstanding the diminished quality of the experience of their spatial features for action). This claim is crucial for the literature. First, it explicitly suggests that the visual experience of motor interactability and the experience of mind-independence do not always correlate, and can be disjointed, though they may be usually considered two simultaneous aspects of our experience of objects. Second, it offers a novel philosophical discussion, showing the significance, for the first time, of this visual impairment, i.e., stereoblindness, for the literature on philosophy of perception. (shrink)

Recent philosophical and empirical contributions strongly suggest that perception attributes determinable properties to its objects. But a characterisation of determinability via attributed properties is restricted to the level of content and does not capture the difference between perceptual belief and perception on this score. In this paper, I propose a formal way of cashing out the difference between determinable belief and perception. On the view presented here, determinability in perception distinctively involves homogeneous representation or representation that exhibits special sorts of (...) formal type variability. This formal characterisation, I suggest, goes beyond traditional approaches to analog representation and parallels a baseline notion of analog computation. (shrink)

This thesis has, as its primary target, the neo-cartesianism, or property dualism of certain philosophers of mind: David Chalmers, Tim Bayne, and others. All begin with a pre-theoretic commitment to the view that all perceptual states are conscious. They define consciousness by saying that it is synonymous with having ‘qualia’ – a term directed at phenomenal properties which defy reduction to physical states. The thesis argues that this position is challenged by certain neurological conditions, - blindsight, visual form agnosia etc- (...) which we can generalise as ‘dissociations’: conditions in which functions are separated from awareness. The thesis holds that these are examples of unconscious perception, which present the case for a different pre-theoretic position, and a redefinition of concepts used in the vicinity. Insofar as the neo-cartesians recognise the empirical, their inclination to reject the dissociations is challenged with new cases and paradigms which have emerged in recent years. It is contended that the dissociations disrupt Chalmers’ coherence between the phenomenal and the psychological, Bayne’s commitment to the Unity of Consciousness, and Phillips’ campaign against unconscious perception. In addition, synaesthesia is advanced as a problem case for Bayne’s unity contention. I argue that the dissociations are not easily dismissed, and present a real challenge for neo-cartesianism. In exploring this challenge, the thesis contributes to the case for a different philosophy of mind – a Higher Order Thought approach. The notion of unconscious perception – it is contended - much more easily finds an accommodation in HOT theories, so this thesis contributes to existing arguments for that position. HOT theories also have an advantage in being receptive to reduction, in giving a developmental account of consciousness, and in being more open to the accommodation of empirical discoveries. In each respect, there is an advantage over the respective positions taken by Chalmers and Bayne. (shrink)