The studies cited by Dijkerman & de Haan (D&dH) stress the distinction between perception and action within the somatosensory system but provide little information about memory functions. Recent findings by our group and by others show that the dorsal stream is also activated during short-term memory maintenance and long-term memory retrieval of haptic information. These data complement and extend the proposed model.

Background. Although genital sensations are an essential aspect of sexual behavior, the cortical somatosensory representation of genitalia in women and men remain poorly known and contradictory results have been reported. Objective. To conduct a systematic review of studies based on electrophysiological and functional neuroimaging studies, with the aim to identify insights brought by modern methods since the early descriptions of the sensory homunculus in the primary somatosensory cortex . Results. The review supports the interpretation that there are (...) two distinct representations of genital sensations in SI, one on the medial surface and the other on the lateral surface. In addition, the review suggests that the secondary somatosensory cortex and the posterior insula support a representation of the affective aspects of genital sensation. Conclusion. In view of the erogenous character of sensations originating in the genitalia, future studies on this topic should systematically assess qualitatively as well as quantitatively the sexually stimulating and/or sexually pleasurable characteristics of sensations felt by subjects in response to experimental stimuli. (shrink)

Previous functional magnetic resonance imaging (fMRI) studies have demonstrated digit somatotopy in primary somatosensory cortex (SI), and even shown that at high spatial resolution it is possible to resolve within-digit somatotopy. However, fMRI studies have failed to resolve the spatial organisation of digit representations in secondary somatosensory cortex (SII). One of the major limitations of high spatial resolution fMRI studies of the somatosensory system has been the long acquisition time needed to acquire slices spanning both SI and (...) SII. Here, we exploit the increased blood oxygenation level dependent contrast of ultra-high-field (7 Tesla) fMRI and the use of multiband imaging to study the topographic organisation in SI and SII with high spatial resolution at the individual subject level. A total of n = 6 subjects underwent vibrotactile stimulation of their face, hand digits and foot (body imaging) and their individual hand digits (digit mapping) for each left and right sides of the body. In addition, n = 2 subjects participated only in the body imaging experiment on both their left and right sides. We show an orderly representation of the face, hand digits and foot in contralateral primary cortex in each individual subject. In SII, there is clear separation of the body areas of the face, hand and foot but the spatial organisation varies across individual subjects. However, separate representation of the individual digits of the hand in SII could not be resolved, even at the spatial resolution of 1.5 mm due to largely overlapping representations. (shrink)

The model presented in the target article includes feature processing and higher representations. I argue, based on neuropsychological evidence, that spatial representations are also involved in perceptual awareness of somatosensory events. Second, there is an asymmetry, with a right-hemisphere–based bilateral representation of the body. Third, the specific aspect of bodily awareness concerning motor function monitoring involves a network that includes the premotor cortex.

Dreyfus enlists the aid of Merleau-Ponty in his critique of representationalist theories of cognition. Such theories posit a representational element at some level of cognitive activity. The nature of the representation and how we think of it will depend upon the level at which one claims to find it. If we consider the case of perception, at one extreme it might be claimed that the representation is a conscious one, that is, that the perceiving subject is conscious of (...) a representation, a _Vorstellung_ in the Kantian sense. In this case, it would clearly come between the perceiving subject and the world and in that sense interfere with a direct perception of the world. This sort of representational theory would be equivalent to idealism, and for good phenomenological reasons it is rejected by Merleau-Ponty and Dreyfus. At the other extreme, it is possible to find cognitive scientists talking about representations at the level of brain activity. Neural representations, either firing patterns or the actual "hard wiring" of neuronal connections (as, for example, neural maps in the somatosensory and motor areas responsible for the experience of the subject's own body), in some way enable perception. At this level of description there are various debates about how these mechanisms can be called representational. If the concept of representation involves reference to the perceptual field, in what sense does a neuronal pattern refer? There are also the familiar debates about how such mechanisms actually function, as well as the difficult problem of how such functions actually translate into personal level experience. Before these debates get off the ground, however, Dreyfus wants to steal the ammunition. He denies that there are representations at the level of brain processes. (shrink)

Based on functional differences, Dijkerman and de Haan emphasize the duality of somatosensory processing and therefore of body representations. But how many body representations do we really have? And what kind of criterion can we use to distinguish them? I review here the empirical and conceptual difficulties in drawing such distinctions and the way to progress.

The main aim of this article is to present and defend a thesis according to which conceptual representations of some types of mental states are encoded in the same neural structures that underlie the first-personal experience of those states. To support this proposal here, I will put forth a novel account of the cognitive function played by ‘shared representations’ of emotions and bodily sensations, i.e. neural structures that are active when one experiences a mental state of a certain type as (...) well as when one observes someone else experiencing a state of the same type. I will argue that shared representations in fact constitute vehicles of certain mental state concepts (more precisely, concepts of specific types of emotions and somatosensory states). The main line of arguing for this will consist in showing that shared representations exhibit specific, ‘conceptual’ functional properties:(1) causal effect on forming metacognitive judgments, (2) cognitive penetrability, (3) diversity of input types. (shrink)

How does neuronal activity give rise to cognitive capacities? To address this question, neuroscientists hypothesize about what neurons “represent,” “encode,” or “compute,” and test these hypotheses empirically. This process is similar to the assessment of hypotheses in other fields of science and as such is subject to the same limitations and difficulties that have been discussed at length by philosophers of science. In this paper, we highlight an additional difficulty in the process of empirical assessment of hypotheses that is unique (...) to the cognitive sciences. We argue that, unlike in other scientific fields, comparing hypotheses according to the extent to which they explain or predict empirical data can lead to absurd results. Other considerations, which are perhaps more subjective, must be taken into account. We focus on one such consideration, which is the purposeful function of the neurons as part of a biological system. We believe that progress in neuroscience critically depends on properly addressing this difficulty. (shrink)

We examined the neural basis of tactile distance perception by analyzing activity patterns induced by tactile stimulation of nine points on a 3 x 3 square grid on the hand dorsum using functional magnetic resonance (fMRI). We used a searchlight approach within pre-defined regions of interests (ROIs) to compute the pairwise Euclidean distances between the activity patterns elicited by tactile stimulation. Then, we used multidimensional scaling (MDS) to reconstruct skin space at the neural level and compare it with skin space (...) at the perceptual level. Our reconstructions of the shape of skin space in contralateral primary somatosensory (SI) and motor (M1) cortices reveal that it is distorted in a way that matches the perceptual shape of skin space. This suggests that early sensorimotor areas are critical to processing tactile distance perception. (shrink)

There are good reasons for wanting to adopt an intentionalist account of experiences generally, an account according to which having an experience is a matter of representing the world as being some way or other—according to which, that is, such mental episodes have intrinsic, conceptual, representational content. Such an approach promises, for example, to provide a satisfying conception of experiences’ subjectivity, their phenomenal character, and their crucial role in constituting reasons for our judgements about the world. It promises this, moreover, (...) without incurring the difficulties that face the adverbialist and the friends of such items as qualia and “private objects”. Still, even many of those who have been persuaded of that much are inclined to make an exception of the bodily sensations, since pains and the rest have traditionally been taken to be peculiarly “blank”—instances of brute, non-conceptual feeling. In this study, I reject that tradition and argue that sensation experiences are indeed representational, and hence not in that respect exceptional. The idea that they are nevertheless distinctive in other ways vis-à-vis ordinary perceptual experiences has led intentionalists such as John McDowell to adopt an account of their content that is both mentalist and radically subjectivist: an account, in other words, that takes the items represented by such experiences to be mental and constitutively dependent on their being represented. To my mind, such subjectivism is both viciously circular—like the parallel view of colours—and at odds with the admirably intentionalist aspirations of these views. Hence I turn to consider objectivist versions of intentionalism, views that assimilate sensations to somatosensory perceptual experiences such as those that inform us of, for example, the position of our own limbs. Admittedly, these views not only risk losing the “interiority” of sensations, but I argue that they also cannot be combined with mentalism and that this generates considerable difficulties—difficulties that have either been ignored or underestimated by those working with less demanding conceptions of content. Nonetheless, I make a number of preliminary moves to show how such difficulties might be dealt with, and how the objectivist can register even the distinctively “inner” character of sensations—by, amongst other things, focussing on the peculiarities of somatosensory content. So the prospects for intentionalism about sensations are, I argue, good. (shrink)

Psychophysical experiments have demonstrated large and highly systematic perceptual distortions of tactile space. Such a space can be referred to our experience of the spatial organisation of objects, at representational level, through touch, in analogy with the familiar concept of visual space. We investigated the neural basis of tactile space by analysing activity patterns induced by tactile stimulation of nine points on a 3 × 3 square grid on the hand dorsum using functional magnetic resonance imaging. We used a searchlight (...) approach within pre-defined regions of interests to compute the pairwise Euclidean distances between the activity patterns elicited by tactile stimulation. Then, we used multidimensional scaling to reconstruct tactile space at the neural level and compare it with skin space at the perceptual level. Our reconstructions of the shape of skin space in contralateral primary somatosensory and motor cortices reveal that it is distorted in a way that matches the perceptual shape of skin space. This suggests that early sensorimotor areas critically contribute to the distorted internal representation of tactile space on the hand dorsum. (shrink)

Tactile distance perception is believed to require that immediate afferent signals be referenced to a stored representation of body size and shape (the body model). For this ability, recent studies have reported that the stored body representations involved are highly distorted, at least in the case of the hand, with the hand dorsum represented as wider and squatter than it actually is. Here, we aim to define the neural basis of this phenomenon. In a behavioural experiment participants estimated the (...) distance between touches on two points by adjusting the length of a visually-presented line on the screen. The technique of multidensional scaling (MDS) was used to reconstruct a perceptual map of tactile space. Analysis of spatial distortion using Procrustes alignment showed that maps were stretched in the mediolateral hand axis. In order to determine the neural correlates of these body distortions, we performed an fMRI study. For each participant, we used a searchlight pattern classifier with Euclidean distance on pre-defined regions of interests (ROIs). In order to relate the representations between the different points and to computational models, we compare response-pattern dissimilarity matrices in these ROIs. Similar to the behavioural experiment, we used MDS to reconstruct maps of the neural representation of tactile space using the values from the dissimilarities matrices. We were able to reconstruct the perceptual map of tactile space in the contralateral primary somatosensory and motor cortices. This suggests that these areas are critical to generate the tactile representations of the dorsum of the hand. (shrink)

The principle of self-organization has acquired a fundamental significance in the newly emerging field of computational philosophy. Self-organizing systems have been described in various domains in science and philosophy including physics, neuroscience, biology and medicine, ecology, and sociology. While system architecture and their general purpose may depend on domain-specific concepts and definitions, there are (at least) seven key properties of self-organization clearly identified in brain systems: 1) modular connectivity, 2) unsupervised learning, 3) adaptive ability, 4) functional resiliency, 5) functional plasticity, (...) 6) from-local-to-global functional organization, and 7) dynamic system growth. These are defined here in the light of insight from neurobiology, cognitive neuroscience and Adaptive Resonance Theory (ART), and physics to show that self-organization achieves stability and functional plasticity while minimizing structural system complexity. A specific example informed by empirical research is discussed to illustrate how modularity, adaptive learning, and dynamic network growth enable stable yet plastic somatosensory representation for human grip force control. Implications for the design of “strong” artificial intelligence in robotics are brought forward. (shrink)

The aim of this paper is to develop and defend an Attentional View of bodily awareness, on which attention is necessary for bodily awareness. The original formulation of the Attentional View is due to Marcel Kinsbourne. First, I will show that the Attentional View of bodily awareness as formulated by Kinsbourne is superior to other accounts in the literature for characterizing the relationship between attention and bodily awareness. Kinsbourne’s account is the only account in the literature so far which can (...) accommodate key neurological diseases such as personal neglect. Second, when I consider Kinsbourne’s view in more detail, I will argue that Kinsbourne’s Attentional View faces problems because it is too reductive. Kinsbourne deviates from the standard taxonomy on which there is a body schema and a body image. Instead he reduces the body image to the neural representation of the body in the somatosensory cortex, the body schema and attentional shifts. I will present two challenges to Kinsbourne’s view which demonstrate that Kinsbourne’s reduction of the body image is unsuccessful. Finally, I will present a revised version of the Attentional View that is both empirically adequate and philosophically satisfactory. (shrink)

Schizophrenia is a mental disorder that calls the mineness of one's own sensations, thoughts and actions into question and threatens the person with a loss of self. In order to understand this illness in its essence, an approach based on phenomenological psychopathology is therefore indispensable. Conversely, disorders of the self in schizophrenia should be of crucial interest for any philosophy of subjectivity in order to test its concepts of self-awareness, personhood and intersubjectivity by reference to empirical phenomena.Contemporary neurobiological concepts of (...) schizophrenia predominantly emphasize the importance of impaired integration of somatosensory inputs into stable central-nervous representations... (shrink)

The conclusions drawn by Benjamin Libet from his work with collegues on the timing of somatosensorial conscious experiences has met with a lot of praise and criticism. In this issue we find three examples of the latter. Here I attempt to place the divide between the two opponent camps in a broader perspective by analyzing the question of the relation between physical timing, neural timing, and experiential timing. The nervous system does a sophisticated job of recombining and recoding messages from (...) the sensorial surfaces and if these processes are slighted in a theory, it might become necessary to postulate weird operations, including subjective back-referral. Neuroscientifically inspired theories are of necessity still based on guesses, extrapolations, and philosophically dubious manners of speech. They often assume some neural correlate of consciousness as a part of the nervous system that transforms neural activity in reportable experiences. The majority of neuroscientists appear to assume that the NCC can compare and bind activity patterns only if they arrive simultaneously at the NCC. This leads to a search for synchrony or to theories in terms of the compensation of differences in neural delays . This is the main dimension of the Libet discussion. Examples from vision research, such as “temporal-binding-by-synchrony” and the “flash-lag” effect, are then used to illustrate these reasoning patterns in more detail. Alternatively one could assume symbolic representations of time and space that are not coded in their own dimension . Unless such tags are multiplexed with the quality message , one gets a binding problem for tags. One of the hidden aspects of the discussion between Libet and opponents appears to be the following. Is the NCC smarter than the rest of the nervous system, so that it can solve the problems of local sign and timing on its own, or are these pieces of information coded symbolically early on in the system? A supersmart NCC appears to be the assumption of Libet's camp . The wish to distribute the smartness evenly across all stages of processing in the nervous system appears to motivate the opponents. I argue that there are reasons to side with the latter group. (shrink)

Human adaptive behavior in sensorimotor control is aimed to increase the confidence in feedforward mechanisms when sensory afferents are uncertain. It is thought that these feedforward mechanisms rely on predictions from internal models. We investigate whether the brain uses an internal model of physical laws to help estimate body equilibrium when tactile inputs from the foot sole are depressed by carrying extra weight. As direct experimental evidence for such a model is limited, we used Judoka athletes thought to have built (...) up internal models of external loads as compared with Non-Athlete participants and Dancers. Using electroencephalography, we first tested the hypothesis that the influence of tactile inputs was amplified by descending cortical efferent signals. We compared the amplitude of P1N1 somatosensory cortical potential evoked by electrical stimulation of the foot sole in participants standing still with their eyes closed. We showed smaller P1N1 amplitudes in the Load compared to No Load conditions in both Non-Athletes and Dancers. This decrease neural response to tactile stimulation was associated with greater postural oscillations. By contrast in the Judoka’s group, the neural early response to tactile stimulation was unregulated in the Load condition. This suggests that the brain can selectively increase the functional gain of sensory inputs, during challenging equilibrium tasks when tactile inputs were mechanically depressed by wearing a weighted vest. In Judokas, the activation of regions such as the right posterior inferior parietal cortex as early as the P1N1 is likely the source of the neural responses being maintained similar in both Load and No Load conditions. An overweight internal model stored in the right PPC known to be involved in maintaining a coherent representation of one’s body in space can optimize predictive mechanisms in situations with high balance constraints. This hypothesis has been confirmed by showing that postural reaction evoked by a translation of the support surface on which participants were standing wearing extra-weight was improved in Judokas. (shrink)

One key issue when conceiving the body as a multisensory object is how the cognitive system integrates visible instances of the self and other bodies with one’s own somatosensory processing, to achieve self-recognition and body ownership. Recent research has strongly suggested that shadows cast by our own body have a special status for cognitive processing, directing attention to the body in a fast and highly specific manner. The aim of the present article is to review the most recent scientific (...) contributions addressing how body shadows affect both sensory/perceptual and attentional processes. The review examines three main points: (1) body shadows as a special window to investigate the construction of multisensory body perception; (2) experimental paradigms and related findings; (3) open questions and future trajectories. The reviewed literature suggests that shadows cast by one’s own body promote binding between personal and extrapersonal space and elicit automatic orienting of attention toward the body-part casting the shadow. Future research should address whether the effects exerted by body shadows are similar to those observed when observers are exposed to other visual instances of their body. The results will further clarify the processes underlying the merging of vision and somatosensation when creating body representations. (shrink)

This article distinguishes three archetypal ways of articulating spatial cognition: (1) via metric representation of objective geometry, (2) via somatosensory constitution of the peripersonal environment, and (3) via pragmatic comprehension of the finalistic sense of action. The last one is documented by neuroscientific studies concerning mirror neurons. Bio-robotic experiments implementing mirror functions confirm the constitutive role of goal-oriented actions in spatial processes.

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)

Theories of embodied cognition abound in the literature, but it is often unclear how to understand them. We offer several interpretations of embodiment, the most interesting being the thesis that mental representations in bodily formats (B-formats) have an important role in cognition. Potential B-formats include motoric, somatosensory, affective and interoceptive formats. The literature on mirroring and related phenomena provides support for a limited-scope version of embodied social cognition under the B-format interpretation. It is questionable, however, whether such a thesis (...) can be extended. We show the limits of embodiment in social cognition. (shrink)

The body is made up of parts. This basic assumption is central in most neuroscientific studies of bodily sensation, body representation and motor action. Yet, the assumption has rarely been considered explicitly. We may indeed ask how the body is internally segmented and how body parts can be defined. That is, how can we sketch the mereology of the body? Here we distinguish between a somatosensory mereology and a motor mereology.

The processes whereby our brains continue to learn about a changing world in a stable fashion throughout life are proposed to lead to conscious experiences. These processes include the learning of top-down expectations, the matching of these expectations against bottom-up data, the focusing of attention upon the expected clusters of information, and the development of resonant states between bottom-up and top-down processes as they reach an attentive consensus between what is expected and what is there in the outside world. It (...) is suggested that all conscious states in the brain are resonant states and that these resonant states trigger learning of sensory and cognitive representations. The models which summarize these concepts are therefore called Adaptive Resonance Theory, or ART, models. Psychophysical and neurobiological data in support of ART are presented from early vision, visual object recognition, auditory streaming, variable-rate speech perception, somatosensory perception, and cognitive-emotional interactions, among others. It is noted that ART mechanisms seem to be operative at all levels of the visual system, and it is proposed how these mechanisms are realized by known laminar circuits of visual cortex. It is predicted that the same circuit realization of ART mechanisms will be found in the laminar circuits of all sensory and cognitive neocortex. Concepts and data are summarized concerning how some visual percepts may be visibly, or modally, perceived, whereas amodal percepts may be consciously recognized even though they are perceptually invisible. It is also suggested that sensory and cognitive processing in the What processing stream of the brain obey top-down matching and learning laws that are often complementary to those used for spatial and motor processing in the brain's Where processing stream. This enables our sensory and cognitive representations to maintain their stability as we learn more about the world, while allowing spatial and motor representations to forget learned maps and gains that are no longer appropriate as our bodies develop and grow from infanthood to adulthood. Procedural memories are proposed to be unconscious because the inhibitory matching process that supports these spatial and motor processes cannot lead to resonance. (shrink)

Recent experimental findings reveal dissociations of conscious and nonconscious performance in many fields of psychological research, suggesting that conscious and nonconscious effects result from qualitatively different processes. A connectionist view of these processes is put forward in which consciousness is the consequence of construction processes taking place in three types of working memory in a specific type of recurrent neural network. The recurrences arise by feeding back output to the input of a central (representational) network. They are assumed to be (...) intemalizations of motor-sensory feedback through the environment. In this manner, a subvocal-phonological, a visuo-spatial, and a somatosensory working memory may have developed. Representations in the central network, which constitutes long-term memory, can be kept active by rehearsal in the feedback loops. The sequentially recurrent architecture allows for recursive symbolic operations and the formation of (auditory, visual, or somatic) models of the external world which can be maintained, transformed and temporarily combined with other information in working memory. Moreover, the quasi-input from the loop directs subsequent attentional processing. The view may contribute to a formal framework to accommodate findings from disparate fields such as working memory, sequential reasoning, and conscious and nonconscious processes in memory and emotion. In theory, but probably not very soon in practice, such connectionist models might simulate aspects of consciousness. (shrink)

We discuss anatomical data that may represent the substrate for very diverse input to a single folium, indirectly supporting the notion of a laterolateral beam spreading along the long axis of a folium. We also raise the question of whether the more linear body representation in somatosensory cortico-ponto-cerebellar pathways represent an adaptation to sequential processing of information from contiguous body parts.

How flexible is language? To what extent does language 'absorb' individual differences, for example physical interaction, in knowledge acquisition within a domain? Current neuropsychological findings show that conceptual knowledge is embodied. When reading the word 'cinnamon', supportive neural activity includes brain areas usually engaged in perceptual tasks. Such findings suggest that perceptual and somatosensory processes influence the conceptual knowledge of the competent language user. Here, I explore what I name the 'plasticity' of language, to hone in on characteristics of (...) language, which, once language is in place, might lessen the necessity of physical interaction with the environment during knowledge acquisition. Linguistic knowledge is acquired by way of structures that contain representations of previous physical interactions. This could explain how a person's experiences transcend the boundary of the individual and meaningfully translate into linguistic knowledge accessible to others, as seems to be the case in so-called interactional expertise; expertise acquired without physical interaction. (shrink)

In bodily awareness body parts are felt to occupy locations relative to the rest of the body. Bodily sensations are felt to be, in Brian O’Shaughnessy’s terms ‘in-a-certain-body-part-at-a-position-in-body-relative-physical-space’. In this paper I put forward a dispositional account of the structure of the spatial content of bodily awareness, which takes inspiration from Gareth Evans’s account of egocentric spatial content in The Varieties of Reference. On the Dispositional View, bodily awareness experiences have spatial content in virtue of a set of connections having (...) been established between somatosensory and proprioceptive inputs on the one hand, and motor outputs on the other hand. This kind of account, according to which spatial content depends constitutively on bodily action, has been challenged by a set of neurological cases and behavioural studies on healthy subjects. The evidence has been used to motivate a functional distinction between two kinds of body representation: representations for perception and representations for action. I review and assess some of the main sources of evidence for this distinction, arguing that the evidence presents a challenge to the dispositional view only if we accept the unjustified assumption that differences in task performance can only be explained in terms of a difference in representation. I close by proposing, and offering some empirical support for, an alternative explanation of the empirical results. The availability of the alternative explanation means that further work is needed to establish whether or not there is any challenge to the Dispositional View. (shrink)

Intra-hemispheric interference has been often observed when body parts with neighboring representations within the same hemisphere are stimulated. However, patterns of interference in early and late somatosensory processing stages due to the stimulation of different body parts have not been explored. Here, we explore functional similarities and differences between attention modulation of the somatosensory N140 and P300 elicited at the fingers vs. cheeks. In an active oddball paradigm, 22 participants received vibrotactile intensity deviant stimulation either ipsilateral or contralateral (...) at the fingers or cheeks. The ipsilateral deviant always covered a larger area of skin than the contralateral deviant. Overall, both N140 and P300 amplitudes were higher following stimulation at the cheek and N140 topographies differed between fingers and cheek stimulation. For the N140, results showed higher deviant ERP amplitudes following contralateral than ipsilateral stimulation, regardless of the stimulated body part. N140 peak latency differed between stimulated body parts with shorter latencies for the stimulation at the fingers. Regarding P300 amplitudes, contralateral deviant stimulation at the fingers replicated the N140 pattern, showing higher responses and shorter latencies than ipsilateral stimulation at the fingers. For the stimulation at the cheeks, ipsilateral deviants elicited higher P300 amplitudes and longer latencies than contralateral ones. These findings indicate that at the fingers ipsilateral deviant stimulation leads to intra-hemispheric interference, with significantly smaller ERP amplitudes than in contralateral stimulation, both at early and late processing stages. By contrast, at the cheeks, intra-hemispheric interference is selective for early processing stages. Therefore, the mechanisms of intra-hemispheric processing differ from inter-hemispheric ones and the pattern of intra-hemispheric interference in early and late processing stages is body-part specific. (shrink)

Based on theoretical considerations of Aurell (1979) and Block (1995), we argue that object recognition awareness is distinct from purely sensory awareness and that the former is mediated by neuronal activities in areas that are separate and distinct from cortical sensory areas. We propose that two of the principal functions of neuronal activities in sensory cortex, which are to provide sensory awareness and to effect the computations that are necessary for object recognition, are dissociated. We provide examples of how this (...) dissociation might be achieved and argue that the components of the neuronal activities which carry the computations do not directly enter the awareness of the subject. The results of these computations are sparse representations (i.e., vector or distributed codes) which are activated by the presentation of particular sensory objects and are essentially engrams for the recognition of objects. These final representations occur in the highest order areas of sensory cortex; in the visual analyzer, the areas include the anterior part of the inferior temporal cortex and the perirhinal cortex. We propose, based on lesion and connectional data, that the two areas in which activities provide recognition awareness are the temporopolar cortex and the medial orbitofrontal cortex. Activities in the temporopolar cortex provide the recognition awareness of objects learned in the remote past (consolidated object recognition), and those in the medial orbitofrontal cortex provide the recognition awareness of objects learned in the recent past. The activation of the sparse representation for a particular sensory object in turn activates neurons in one or both of these regions of cortex, and it is the activities of these neurons that provide the awareness of recognition of the object in question. The neural circuitry involved in the activation of these representations is discussed. (shrink)

Abstract A unique aspect of human communication is the utilization of sets of well- delineated entities, the morphology of which is used to encode the letters of the alphabet. In this paper, we focus on Braille as an exemplar of this phenomenon. We take a Braille cell to be a physical artifact of the human environment, into the structure of which is encoded a representation of a letter of the alphabet. The specific issue we address in this paper concerns (...) an examination of how the code that is embedded in the structure of a Braille cell is transferred with fidelity from the environment through the body and into the Braille reader’s brain. We describe four distinct encoding steps that enable this transfer to occur. (shrink)

Viewed this way, the texts yield striking examples of language and notation that are irreducibly ambiguous and productive because they are ambiguous.

The on-going debate over the ‘admissible contents of perceptual experience’ concerns the range of properties that human beings are directly acquainted with in perceptual experience. Regarding vision, it is relatively uncontroversial that the following properties can figure in the contents of visual experience: colour, shape, illumination, spatial relations, motion, and texture. The controversy begins when we ask whether any properties besides these figure in visual experience. We argue that ‘ensemble properties’ should be added to the list of visually admissible properties. (...) Ensemble properties are features that belong to a set of perceptible objects as a whole as opposed to the individuals that constitute that set. They include such features as the mean size of an array of shapes or the average emotional expression of an array of faces. Recent work in vision science has yielded compelling evidence that the visual system routinely encodes such properties. We argue that epistemological considerations provide strong reasons to think that these properties figure in visual experience. Judgements about ensemble properties are immediately warranted by our perceptual experience, and the only plausible way that a perceptual experience could confer this warrant is if it confers awareness of ensemble properties. (shrink)

In the nearly half a century since its modern inception (Anscombe (1965), Hintikka (1969)), the Representation theory has faced no more implacable enemy than Ned Block. He has offered objection after objection, usually in the form of apparent counterexamples, and as I write this he shows no sign of flagging.

The duality theory established by Halmos in [2] for boolean hemimorphism applies of course to the diagonalizable algebra, because ντν is an hemimorphism. For commodity in working on diagonalizable algebras we recall the basic facts and give the characteristic conditions on the dual of ντν.

I develop a theory of (mental) reference according to which there are two ways of referring to an object. One can refer to an object by relying on a previous instance of successful reference to that (or some other) object. I call this type of reference 'dependent reference'. Alternatively, one can refer to an object 'independently'. A referential attempt is independent if and only if it is not dependent. I argue that these two types of reference differ as they adhere (...) to different norms. While it may be possible to think about an object without the ability to uniquely individuate it if one thinks about it dependently, the same may not hold true in the case of independent thought. At least, the classic arguments that attempt to demonstrate the possibility of thinking about something without the ability to uniquely individuate it are irrelevant to independent reference. Furthermore, not all reference could be dependent. -/- Along the way, I do a few other things as well. (shrink)

I recently discovered that work I was doing in the laboratory and in theoretical writings was implicitly taking a position on a set of questions that philosophers had been worrying about for much of the past 30 or more years. My clandestine involvement in philosophical issues began when a computer science colleague and I were trying to build a model of geometrical reasoning that would draw a diagram and notice things in the diagram as it drew it (Pylyshyn, Elcock, Marmor, (...) & Sander, 1978). One problem we found we had to face was that if the system discovered a right angle it had no way to tell whether this was the intersection of certain lines it had drawn earlier while constructing a certain figure, and if so which particular lines they were. Moreover, the model had no way of telling whether this particular right angle was identical to some bit of drawing it had earlier encountered and represented as, say, the base of a particular triangle. There was, in other words, no way to determined the identity of an element (I use the term “element” when referring to a graphical unit such as used in experiments. Otherwise when speaking informally I use the term “thing” on the grounds that nobody would mistake that term for a technical theoretical construct. Eventually I end up calling them “Visual Objects” to conform to usage in psychology) at two different times if it was represented differently at those times. This led to some speculation about the need for what we called a “finger” that could be placed at a particular element of interest and that could be used to identify it as particular token thing (the way you might identify a particular feature on paper by labeling it). In general we needed something like a finger that would stay attached to a particular element and could be used to maintain a correspondence between the individual element that was just noticed now and one that had been represented in some fashion at an earlier time. The idea of such fingers (which.... (shrink)

In this paper, I take scientific models to be epistemic representations of their target systems. I define an epistemic representation to be a tool for gaining information about its target system and argue that a vehicle’s capacity to provide specific information about its target system—its informativeness—is an essential feature of this kind of representation. I draw an analogy to our ordinary notion of interpretation to show that a user’s aim of faithfully representing the target system is necessary for (...) securing this feature. (shrink)

The aim of this article is to adapt Peirce’s semiotics to the study of media and arts. While some Peircean notions are criticized and rejected, constructive ways of understanding Peirce’s ideas are suggested, and a number of new notions, which are intended to highlight crucial aspects of semiosis, are then introduced. All these ideas and notions are systematically related to one another within the frames of a consistent terminology. The article starts with an investigation of Peirce’s three sign constituents and (...) their interrelations: the representamen, the object, and the interpretant. A new approach to the interrelations of these three sign constituents is then suggested and manifested in a distinction between representation and neopresentation. This is followed by a critical discussion of Peirce’s three types of representation—iconicity, indexicality, and symbolicity—and their interrelations, which sets the stage for a presentation of what is referred to as the material and mental representation model. This model aims to illuminate the problematic relation between material and mental facets of signification triggered by media and art products, and other material things and phenomena. (shrink)

In their constructive reviews, Frances Egan, Randy Gallistel and Steven Gross have raised some important problems for the account of content advanced by Nicholas Shea in Representation in Cognitive Science. Here the author addresses their main challenges. Egan argues that the account includes an unrecognised pragmatic element; and that it makes contents explanatorily otiose. Gallistel raises questions about homomorphism and correlational information. Gross puts the account to work to resolve a dispute about probabilistic contents in perception, but argues that (...) a question remains about whether probabilities are found in the content or instead in the manner of representation. (shrink)