We owe the problem of the speckled hen to Gilbert Ryle. It was suggested to A.J. Ayer by Ryle in connection with Ayer’s account of seeing. Suppose that you are standing before a speckled hen with your eyes trained on it. You are in good light and nothing is obstructing your view. You see the hen in a single glance. The hen has 47 speckles on its facing side, let us say, and the hen ap­ pears speckled to you. On (...) Ayer’s view, in seeing the hen, you directly see a speckled sense-datum or appearance. Ryle wondered how many speckles there are on the sense-datum. After all, intu­ itively, the hen does not appear to you to have 47 speckles. And if this is the case, then it does not present to you an appearance with 47 speckles. Equally, however, the hen does not appear to you not to have 47 speckles. So, it does not present an appearance that lacks 47 speckles either. (shrink)

Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the ‘dynamic core’). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized (...) properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well. (shrink)

In recent years there has been an explosion of scientific work on consciousness in cognitive neuroscience, psychology, and other fields. It has become possible to think that we are moving toward a genuine scientific understanding of conscious experience. But what is the science of consciousness all about, and what form should such a science take? This chapter gives an overview of the agenda.

To investigate the possible dichotomy between the neurophysiological bases of perceptual transitions versus sustaining a particular percept over time, an fMRI study was conducted with subjects viewing fragmented pictures. Unlike most other perceptually unstable stimuli, fragmented pictures give rise to only one perceptual transition and a continuous period of sustained perception. Earlier research is inconclusive on the subject of which anatomical regions should be attributed to what temporal aspect of perception, and the aim of the present study was to shed (...) more light on the subject. In this study occipitotemporal and fronto-parietal regions were found to be activated for both aspects. However, regions in the medial-temporal lobe were activated specifically for transitions, whereas medial and dorsolateral prefrontal regions were activated specifically for sustained perception. These results provide further support for the theory that the initial creation of perceptual awareness and upholding perceptual awareness over time are separate processes involving different brain regions. (shrink)

Dienes and Seth (2010) conclude that confidence ratings and post-decision wagering are two comparable and recommendable measures of conscious experience. In a recently submitted paper, we have however found that both methods are problematic and seem less suited to measure consciousness than a direct introspective measure. Here, we discuss the methodology and conclusions put forward by Dienes and Seth, and why we think the two experiments end up with so different recommendations.

The goal of perceptual systems is to allow organisms to adaptively respond to ecologically relevant stimuli. Because all perceptual inputs are ambiguous, perception needs to rely on prior knowledge accumulated over evolutionary and developmental time to turn sensory energy into information useful for guiding behavior. It remains controversial whether the guidance of perception extends to cognitive states or is locked up in a “cognitively impenetrable” part of perception. I argue that expectations, knowledge, and task demands can shape perception at multiple (...) levels, leaving no part untouched. The position advocated here is broadly consistent with the notion that perceptual systems strive to minimize prediction error en route to globally optimal solutions :181–204, 2013). On this view, penetrability should be expected whenever constraining lower-level processes by higher level knowledge is minimizes global prediction error. Just as Fodor feared cognitive penetration of perception threatens theory-neutral observation and the distinction between observation and inference. However, because theories themselves are constrained by the task of minimizing prediction error, theory-laden observation turns out to be superior to theory-free observation in turning sensory energy into useful information. (shrink)

Carruthers considers and rejects a mixed position according to which we have interpretative access to unconscious thoughts, but introspective access to conscious ones. I argue that this is too hasty. Given a two-level view of the mind, we can, and should, accept the mixed position, and we can do so without positing additional introspective mechanisms beyond those Carruthers already recognizes.

This article focuses on, and critiques, Goldman’s view that third-person mind-reading is grounded in first-person introspection. It argues, on the contrary, that first-person awareness of propositional attitude events is always interpretative, resulting from us turning our mind-reading abilities upon ourselves.

This article examines what is known about the cognitive science of working memory, and brings the findings to bear in evaluating philosophical accounts of central cognitive processes of thinking and reasoning. It is argued that central cognition is sensory based, depending on the activation and deployment of sensory images of various sorts. Contrary to a broad spectrum of philosophical opinion, the central mind does not contain any workspace within which goals, decisions, intentions, or non-sensory judgments can be active.Introduction: philosophers’ commitmentsMost (...) philosophers believe that our so-called “personal-level” propositional attitudes—our personal judgments, beliefs, goals, values, decisions, and intentions—are consciously accessible. Many will also allow, of course, that some of the processing that takes place within our perceptual faculties is inaccessible to us; and many will grant the possibility of unconscious attitudes, as well as processes of inference and decision mak. (shrink)

This paper will argue that there is no such thing as introspective access to judgments and decisions. It won't challenge the existence of introspective access to perceptual and imagistic states, nor to emotional feelings and bodily sensations. On the contrary, the model presented in Section 2 presumes such access. Hence introspection is here divided into two categories: introspection of propositional attitude events, on the one hand, and introspection of broadly perceptual events, on the other. I shall assume that the latter (...) exists while arguing that the former doesn't (or not in the case of judgments and decisions, at least). Section 1 makes some preliminary points and distinctions, and outlines the scope of the argument. Section 2 presents and motivates the general model of introspection that predicts a divided result. Section 3 provides independent evidence for the conclusion that judgments and decisions aren't introspectable. Section 4 then replies to a number of objections to the argument, the most important of which is made from the perspective of so-called "dual systems theories" of belief formation and decision making. The upshot is a limited form of eliminativism about introspection, in respect of at least two core categories of propositional attitude. (shrink)

Using a metacontrast masking paradigm, prior studies have shown that a target’s color information and form information, can be processed without awareness and that unconscious color processing occurs at early, wavelength-dependent levels in the cortical information processing hierarchy. Here we used a combination of paracontrast and metacontrast masking techniques to explore unconscious color and form priming effects produced by blue, green, and neutral stimuli. We found that color priming in normal observers is significantly reduced when an additional paracontrast mask precedes (...) the target at optimal masking SOAs. However, no reduction of form-priming effects was obtained at similar optimal paracontrast SOAs. We conclude that unconscious color priming depends on an early, wavelength- or stimulus-dependent response of color neurons located at early cortical levels whereas unconscious form priming occurs at later levels. (shrink)

The study of the neural correlates of awareness is nowadays an active research field in Neuroscience. This has been basically boosted by the study of neural correlates of conscious perception with single cell recordings in monkeys and voxel activities with human fMRI experiments. In this review, we discuss the main experiments with recording of single neurons and related evidence about the neural events underling visual perceptual awareness.

Why was Ivan Pavlevich Pavlov so widely celebrated in the decades after 1900? As his story of the 'freedom reflex' illustrates, Pavlov often overstated his observations. By calling all innate behaviour a reflex and all learned behaviour a conditional reflex, he meant to eliminate consciousness and volition from science. Pavlov's universal reflex explanation became the prototype for behaviourism.