It has been argued that attention and awareness might oppose each other given that attending to an adapting stimulus weakens its afterimage. We argue instead that the type of attention guided by the spread of attention and the level of processing is critical and might result in differences in awareness using afterimages. Participants performed a central task with small, large, local or global letters and a blue square as an adapting stimulus in two experiments and indicated the onset and offset (...) of the afterimage. We found that increases in the spatial spread of attention resulted in the decrease of afterimage duration. In terms of levels of processing, global processing produced larger afterimage durations with stimuli controlled for spatial extent. The results suggest that focused or distributed attention produce different effects on awareness, possibly through their differential interactions with polarity dependent and independent processes involved in the formation of color afterimages. (shrink)

A tacit assumption in the field of consciousness studies is that the more empirical evidence a theory can explain, the better it fares when weighed against competitors. If one wants to take seriously the potential for empirical evidence to move forward debates in consciousness studies, there is a need to gather, organize, validate, and compare evidence. We present an inference to the best explanation (IBE) process on the basis of empirical support that is applicable in debates between competing theories of (...) consciousness. Our proposed IBE process consists in four steps: Assimilate, Compile, Validate, and Compare. Until now, the vast majority of the work in the field has consisted in gathering empirical evidence for theories i.e., the assimilation step. To illustrate the feasibility of our proposed IBE process, and what it may look like when applied in practice, we deliver a complete collection (the compilation step) of empirical support for the distinction between A-Consciousness and P-Consciousness and the overflow hypothesis. Finally, we offer an example of the validation step, by scrutinizing the interpretation of aphantasics’ performance on retro-cue paradigms offered in the literature in support of the overflow hypothesis. The compilation we deliver here is the first effort in the IBE process, the end result of which — hopefully — will be the ability of the research community to carry out side-by-side comparisons of theories and the empirical phenomena they claim to explain, i.e., the comparison step. (shrink)

(2013). Does consciousness entail subjectivity? The puzzle of thought insertion. Philosophical Psychology: Vol. 26, No. 2, pp. 291-314. doi: 10.1080/09515089.2011.625117.

Dartnall claims that visual short-term memory stores nonconceptual content , in the form of compressed images. In this paper I argue against the claim that NCC can be stored in VSTM. I offer four reasons why NCC cannot be stored in visual memory and why only conceptual information can: NCC lasts for a very short time and does not reach either visual short-term memory or visual long-term memory; the content of visual states is stored in memory only if and when (...) object-centered attention modulates visual processing and this modulation signifies the onset of the conceptualization of that content; only categorical high-level information that characterizes conceptual content and not metric and precise iconic information that characterizes NCC can be stored in visual memory for long periods; and if NCC were stored in visual memory then this would allow recognitional judgments pertaining to NCC—one could recognize the precise shade of a color that one had seen before. However NCC does not allow such recognitional judgments. (shrink)

Perceptual experiences justify beliefs. A perceptual experience of a dog justifies the belief that there is a dog present. But there is much evidence that perceptual states can occur without being conscious, as in experiments involving masked priming. Do unconscious perceptual states provide justification as well? The answer depends on one’s theory of justification. While most varieties of externalism seem compatible with unconscious perceptual justification, several theories have recently afforded to consciousness a special role in perceptual justification. We argue that (...) such views face a dilemma: either consciousness should be understood in functionalist terms, in which case our best current theories of consciousness do not seem to imbue consciousness with any special epistemic features, or it should not, in which case it is mysterious why only conscious states are justificatory. We conclude that unconscious perceptual justification is quite plausible. (shrink)

Consciousness is central to our lived experience. It is unsurprising, then, that the topic has captivated many students, neuroscientists, philosophers, and other theorists working in cognitive science. But consciousness may seem especially difficult to explain. This is in part because the term “consciousness” has been used in many different ways. The goal of this chapter is to explore several kinds of consciousness: what theorists have called “creature,” “phenomenal,” “access,” “state,” “transitive,” “introspective,” and “self” consciousness. The basic distinctions among these kinds (...) of consciousness are described in Section 1. Section 2 raises potential challenges for explaining these varieties of consciousness and describes a few current theories of them. Section 3 closes the chapter by exploring directions for future work in the cognitive science of consciousness. Along the way, some of the possible interrelationships among these kinds of consciousness are discussed. (shrink)

Muchos psiquiatras se encuentran constantemente con pacientes cuyos síntomas incluyen trastornos o alteraciones de la conciencia. Infortunadamente, el significado del término conciencia es poco claro. Este artículo hace un repaso sistemático de varios significados atribuidos a dicho término, así como de diversos problemas filosóficos asociados. Asimismo, reconstruye varias teorías filosóficas y científicas de la conciencia, identificando sus ventajas y desventajas. Al final, ofrece algunas sugerencias para el uso del término conciencia en la psiquiatría.

We agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.

: Fodor argues that perceptual representations are a subset of iconic representations, which are distinguished from symbolic/discursive representations. Iconic representations are nonconceptual and they do not support the abilities afforded by concepts. Iconic representations, for example, cannot support object individuation. If someone thinks that perception or some of its parts has imagistic NCC, they face the following dilemma. Either they will have to accept that this NCC does not allow for object individuation, but it represents instead conglomerations of properties and (...) at some stage of visual processing it must interface with cognition and its conceptual capacities for the visual objects to be individuated. Or, they will have to hold that the imagistic, NCC of perception, allows for object individuation. I opt for the second thesis because I think there is strong empirical evidence that objects are individuated during early vision. I also think that early vision individuates objects by means of, what I had previously called nonconceptual perceptual demonstrative reference. I argue, first, why Fodor’s view that iconic NCC does not enable object individuation is false. I also argue, contra Fodor, that early vision allows the perception of the cardinality of sets of objects. Keywords : Early Vision; Analog Representations; Object Individuation; Arithmetic Cognition; Cardinality of Sets L'individuazione di oggetti mediante il contenuto iconico: come è rappresentata la numerosità nella rappresentazione iconica? Riassunto: Per Fodor le rappresentazioni percettive sono un sottoinsieme delle rappresentazioni iconiche, distinte dalle rappresentazioni simbolico/discorsive. Le rappresentazioni iconiche sono nonconcettuali e non supportano le abilità richieste dai concetti. Le rappresentazioni iconiche, per esempio, non supportano l'individuazione di oggetti. Se si pensa che la percezione o qualche sua parte abbia un contenuto nonconcettuale come immagine, si ci si imbatte nel seguente dilemma. O si accetta che il NCC non permetta di individuare oggetti, ma che rappresenti conglomerati di proprietà e che si interfacci con la cognizione e le sue capacità concettuali, per individuare gli oggetti visivi. O si dice che l'immagine, il NCC, della percezione consenta di individuare oggetti. Propendo per la seconda tesi, poiché penso che ci sia solida evidenza empirica per cui gli oggetti vengono individuati durante le prime fasi della visione, in cui l’individuazione avviene mediante quanto definito come riferimento dimostrativo del contenuto nonconcettuale percettivo. Chiarirò le ragioni per cui la concezione di Fodor, per cui il contenuto nonconcettuale iconico non supporta l’individuazione di oggetti, è falsa. Inoltre, contra Fodor, sosterrò che le prime fasi della visione permettono la percezione della cardinalità di insiemi di oggetti. Parole chiave: Prime fasi della visione; Rappresentazioni analogiche; Individuazione di oggetti; Cognizione aritmetica; Cardinalità degli insiemi. (shrink)

According to the influential thesis of attentional transparency, in having or reflecting on an ordinary visual experience, we can attend only outwards, to qualities the experience represents, never to intrinsic qualities of the experience itself, i.e., to “mental paint.” According to the competing view, attentional semitransparency, although we usually attend outwards, to qualities the experience represents, we can also attend inwards, to mental paint. So far, philosophers have debated this topic in strictly armchair means, especially phenomenological reflection. My aim in (...) this paper is to show how to design an experiment, using the change detection paradigm for studying visual working memory that, if yielding positive results, would support AS. The structure of the argument is as follows. In standard change detection tasks, which involve attention to qualities the experience represents, there exists a known object integration effect (Luck and Vogel in Nature 390(6657):279–281, 1997). I formulate a hypothesis I call “the turn-off hypothesis,” according to which this effect does not exist in change detection tasks where subjects are instructed to attend to mental paint. I argue that, given AS, we have some reason to expect the turn-off hypothesis to be true, but given AT, we do not. Consequently, the truth of the turn-off hypothesis would support AS. I further argue that one can straightforwardly test the turn-off hypothesis, taking the standard change detection paradigm and instructing participants to attend inwards. (shrink)

What is the philosophical significance of attention? The present article provides an overview of recent debates surrounding the connections between attention and other topics of philosophical interest. In particular, it discusses the interplay between attention and consciousness, attention and agency, and attention and reference. The article outlines the questions and contemporary positions concerning how attention shapes the phenomenal character of experience, whether it is necessary or sufficient for consciousness, and whether it plays a special role in the best philosophical theories (...) of action or conceptual reference. Various interdependencies between the answers to these questions are indicated, as well as how these answers might depend on the metaphysics of attention. Together with its companion piece this article serves as an introduction to the philosophy of attention. (shrink)

I propose that primary conscious awareness arises from synchronized activity in dendrites of neurons in dorsal thalamic nuclei, mediated particularly by inhibitory interactions with thalamic reticular neurons. In support, I offer four evidential pillars: consciousness is restricted to the results of cortical computations; thalamus is the common locus of action of brain injury in vegetative state and of general anesthetics; the anatomy and physiology of the thalamus imply a central role in consciousness; neural synchronization is a neural correlate of consciousness.

In this paper, I want to argue for two main and related points. First, I want to defend Richard Wollheim’s well-known thesis that the twofold mental state of seeing-in is the distinctive pictorial experience that marks figurativity. Figurativity is what makes a representation pictorial, a depiction of its subject. Moreover, I want to show that insofar as it is a mark of figurativity, all seeing-in is inflected. That is to say, every mental state of seeing-in is such that the characterisation (...) of the properties by which a certain subject is seen in a given picture as having refers to the design properties of the picture’s vehicle, i.e., to the visible surface properties of that vehicle that are responsible for the fact that one such subject is seen in it, precisely taken in such a design role. Finally, I will try to show that seeing-in is qualified by inflection independently of whether it is conscious or unconscious seeing-in. (shrink)

The aim of the present study was to investigate how saccadic selection relates to people’s awareness of the saliency and identity of a saccade goal. Observers were instructed to make an eye movement to either the most salient line segment or the only right-tilted element in a visual search display. The display was masked contingent on the first eye movement and after each trial observers indicated whether or not they had correctly selected the target. Whereas people’s awareness concerning the saliency (...) of the saccade goal was generally low, their awareness concerning the identity was high. Observers’ awareness of the saccade goal was not related to saccadic performance. Whereas saccadic selection consistently varied as a function of saccade latency, people’s awareness concerning the saliency or identity of the saccade goal did not. The results suggest that saccadic selection is primarily driven by subconscious processes. (shrink)

Inattentional blindness is the failure to perceive salient stimuli presented at unattended locations. Whereas the behavioral manifestation of inattentional blindness has been investigated, the neural basis of this phenomenon has remained elusive. In the current study, event-related fMRI was used to identify the neural substrates associated with inattentional blindness. During central fixation, participants named colored digits presented at a peripheral location. On a subset of trials, an unexpected checkerboard circle was presented at the same eccentricity along with the colored digits (...) . Neural activity during inattentional blindness was observed in the prefrontal cortex. Together with previous findings, these results call into question the widespread view that activity in the prefrontal cortex reflects conscious processing. (shrink)

A modified flanker task was used to assess the effects of spatial attention during conscious and nonconscious processing. In line with prior findings, we demonstrated that increasing spatial separation between flankers and probes diminished the differences between reaction times to the incongruent and congruent probe–flanker pairs. This trend occurred even when the identity of flankers was suppressed from awareness by a metacontrast mask, indicating that spatial attention can be allocated to information processed at the nonconscious, in addition to the conscious, (...) levels, that effects of spatial attention at these two levels can be equivalent, and that attention deployed at the nonconscious level of processing can be characterized by a spatial gradient that is nearly identical to that found at the conscious level of processing. (shrink)

Theories of philosophy of perception are too simplifying. Direct realism and representationalism, for example, are philosophical theories of perception about the nature of the perceived object and its location. It is common sense to say that we directly perceive, through our senses, physical objects together with their properties. However, if perceptual experience is representational, it only appears that we directly perceive the represented physical objects. Despite psychological studies concerning the role of memory in perception, what these two philosophical theories do (...) not explicate are the continuity of the external describable object and the role of memory in perceiving the continuity, difference, break or ending. Using empirical evidence of particular cases and the hypothetico-deductive model, this research article analyses how one is able to perceive the continuity of same things. The early stages of perceptual process are not sufficient for the perception of continuity. Empirical evidence of memory disorders shows that persons with a memory disorder do not perceive the same thing or the familiar place they previously saw and now experience or remember what they are thinking about, even if the object, the place or the person has remained the same. I will argue that the perception of continuity requires memory. In fact, observation indicates how the memory runs at the same time, when the object is seen over time. This fact implies the memory system’s essential role for perceiving the continuity of the same things. (shrink)

Zenon Pylyshyn argues that cognitively driven attentional effects do not amount to cognitive penetration of early vision because such effects occur either before or after early vision. Critics object that in fact such effects occur at all levels of perceptual processing. We argue that Pylyshyn’s claim is correct—but not for the reason he emphasizes. Even if his critics are correct that attentional effects are not external to early vision, these effects do not satisfy Pylyshyn’s requirements that the effects be direct (...) and exhibit semantic coherence. In addition, we distinguish our defense from those found in recent work by Raftopoulos and by Firestone and Scholl, argue that attention should not be assimilated to expectation, and discuss alternative characterizations of cognitive penetrability, advocating a kind of pluralism. (shrink)

The non-transitivity of the relation looks the same as has been used to argue that the relation has the same phenomenal character as is non-transitive—a result that jeopardizes certain theories of consciousness. In this paper, I argue against this conclusion while granting the premise by dissociating lookings and phenomenology; an idea that some might find counter-intuitive. However, such an intuition is left unsupported once phenomenology and cognitive access are distinguished from each other; a distinction that is conceptually and empirically grounded.

People categorize objects slowly when visual input is highly impoverished instead of optimal. While bottom-up models may explain a decision with optimal input, perceptual hypothesis testing (PHT) theories implicate top-down processes with impoverished input. Brain mechanisms and the time course of PHT are largely unknown. This event-related potential study used a neuroimaging paradigm that implicated prefrontal cortex in top-down modulation of occipitotemporal cortex. Subjects categorized more impoverished and less impoverished real and pseudo objects. PHT theories predict larger impoverishment effects for (...) real than pseudo objects because top-down processes modulate knowledge only for real objects, but different PHT variants predict different timing. Consistent with parietal-prefrontal PHT variants, around 250 ms, the earliest impoverished real object interaction started on an N3 complex, which reflects interactive cortical activity for object cognition. N3 impoverishment effects localized to both prefrontal and occipitotemporal cortex for real objects only. The N3 also showed knowledge effects by 230 ms that localized to occipitotemporal cortex. Later effects reflected (a) word meaning in temporal cortex during the N400, (b) internal evaluation of prior decision and memory processes and secondary higher-order memory involving anterotemporal parts of a default mode network during posterior positivity (P600), and (c) response related activity in posterior cingulate during an anterior slow wave (SW) after 700 ms. Finally, response activity in supplementary motor area during a posterior SW after 900 ms showed impoverishment effects that correlated with RTs. Convergent evidence from studies of vision, memory, and mental imagery which reflects purely top-down inputs, indicates that the N3 reflects the critical top-down processes of PHT. A hybrid multiple-state interactive, PHT and decision theory best explains the visual constancy of object cognition. (shrink)

Consistent with numerous electrophysiological studies, we recently reported that conscious perception is associated with a widely distributed modulation of the P3 component . We also showed that correct objective performance in the absence of subjective awareness is associated with a spatially more restricted modulation of the P3. The relatively late occurrence of the P3 along with lack of control for post-perceptual processes suggests that this component might reflect processes related to stimulus evaluation or confidence rather than to visual awareness or (...) objective performance. The main aim of the current study was to test this hypothesis. While EEG was recorded, participants performed a forced-choice localization task and reported their subjective perception of the target on a 3-level scale that also indexed their confidence. The results showed that our previous findings are replicated when confidence is controlled for. (shrink)

Contrary to Block's assertion, “identity-crowding” does not provide an interesting instance of object-seeing without object-attention. The successful judgments and unusual phenomenology of identity-crowding are better explained by unconscious perception and non-perceptual phenomenology associated with cognitive states. In identity-crowding, as in other cases of crowding, subjects see jumbled textures and cannot individuate the items contributing to those textures in the absence of attention. Block presents an attenuated sense in which identity-crowded items are seen, but this is irrelevant to the debate about (...) phenomenal experience of an object in the absence of object-attention. Finally, even unconscious object perception in identity-crowding likely involves an attention-like selective process. (shrink)

Can unattended objects by seen? Ned Block has claimed they can on the basis of “identity-crowding.” This paper summarizes the ensuing debate with particular emphasis on the role of unconscious perception. Although unconscious perception plays an important role, it cannot support conscious object-seeing in identity-crowding. Nevertheless, unconscious perception assists in making successful judgments about unseen objects. Further, compelling conceptual evidence against seeing unattended objects places the burden of proof on Block. I argue that countability is necessary for seeing objects and (...) sufficient for attention to them; thus, no unattended objects are seen. (shrink)

Human vision briefly retains a trace of a stimulus after it disappears. This trace—iconic memory—is often believed to be a surrogate for the original stimulus, a representational structure that can be used as if the original stimulus were still present. To investigate its nature, a flicker-search paradigm was developed that relied upon a full scan (rather than partial report) of its contents. Results show that for visual search it can indeed act as a surrogate, with little cost for alternating between (...) visible and iconic representations. However, the duration over which it can be used depends on the type of task: some tasks can use iconic memory for at least 240 ms, others for only about 190 ms, while others for no more than about 120 ms. The existence of these different limits suggests that iconic memory may have multiple layers, each corresponding to a particular level of the visual hierarchy. In this view, the inability to use a layer of iconic memory may reflect an inability to maintain feedback connections to the corresponding representation. (shrink)

While substantial progress has been made in the field known as artificial consciousness, at the present time there is no generally accepted phenomenally conscious machine, nor even a clear route to how one might be produced should we decide to try. Here, we take the position that, from our computer science perspective, a major reason for this is a computational explanatory gap: our inability to understand/explain the implementation of high-level cognitive algorithms in terms of neurocomputational processing. We explain how addressing (...) the computational explanatory gap can identify computational correlates of consciousness. We suggest that bridging this gap is not only critical to further progress in the area of machine consciousness, but would also inform the search for neurobiological correlates of consciousness and would, with high probability, contribute to demystifying the “hard problem” of understanding the mind–brain relationship. We compile a listing of previously proposed computational correlates of consciousness and, based on the results of recent computational modeling, suggest that the gating mechanisms associated with top-down cognitive control of working memory should be added to this list. We conclude that developing neurocognitive architectures that contribute to bridging the computational explanatory gap provides a credible and achievable roadmap to understanding the ultimate prospects for a conscious machine, and to a better understanding of the mind–brain problem in general. (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)