We call those gestures “instrumental” that can enhance certain thinking processes of an agent by offering him representational models of his actions in a virtual space of imaginary performative possibilities. We argue that pointing is an instrumental gesture in that it represents geometrical information on one’s own gaze direction, and provides a ritualized template for initiating gaze coordination and joint attention. We counter two possible objections, asserting respectively that the representational content of pointing is not constitutive, but derived from language, (...) and that pointing directly solicits gaze coordination, without representing it. We consider two studies suggesting that attention and spatial perception are actively modified by one’s own pointing activity: the first study shows that pointing gestures help children link sets of objects to their corresponding number words; the second, that adults are faster and more accurate in counting when they point. (shrink)

Ferdinand Pöhlmann argues that a sense of one’s own basic abilities to move is a constitutive condition on the ability to perceive the world spatially. This constitutive relation explains why egocentric spatial representation is to be regarded as a kind of self-representation. In arguing for these claims, conceptual as well as empirical questions are discussed and an overview of accounts that take action as a constitutive condition on spatial representation is given. The picture that emerges is linked to the phenomenological (...) (Scheler) as well as to the analytic (Evans) tradition in the Philosophy of Mind.​. (shrink)

Milner and Goodale's model of the primate cortical visual system has been justly influential in shaping recent empirical and theoretical work on the neural basis of conscious vision. In this commentary I examine the extent to which their model accounts for recent neuropsychological findings from patients with visual neglect and extinction, two profound disorders of visual consciousness that arise after unilateral brain damage. I begin by outlining two key claims from their model: first, that the characteristic loss of awareness for (...) contralesional sensory inputs in neglect reflects disruption of ventral, object-recognition processes, rather than dorsal processes as has commonly been thought; and second, that extinction of the more contralesional of two concurrent stimulus events is primarily a disorder of orienting and action-related attention arising from damage to the dorsal, visuomotor stream. I then present recent findings that cast some doubt on these claims. Visual neglect arising from damage to the inferior parietal lobe can involve a significant visuomotor impairment, independent of any perceptual deficit. Moreover, visual extinction can be modulated by perceptual factors that are likely to call upon the ventral object-recognition stream. These findings suggest that neglect and extinction, two relatively common and striking disorders of consciousness, are not readily accommodated within Milner and Goodale's two visual streams model. (shrink)

This paper examines the epistemic status of the reflective belief about the content of one’s own conscious mental state, with emphasis on perceptual experience. I propose that the process that gives a special epistemic status to a reflective belief is not observation, inference, or conceptual articulation, but semantic ascent similar to the transition from a sentence in the object language to a sentence in the meta-language that affirms the truth of the original sentence. This account of the process of reflection (...) explains why a reflective belief is (subject to some qualification) infallible. (shrink)

This thesis investigates the representation of phonological language aspects in the healthy human brain, especially the contribution of the right hemisphere. Using functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS), it is demonstrated that the left and right supramarginal gyri are essential for phonological processing. It is also shown that the left as well as the right posterior inferior frontal gyri contribute to efficient phonological decisions. Finally, an fMRI study reveals a frontal network for phonological aspects of language (...) production. These results demonstrate a contribution of both hemispheres to efficient phonological aspects of language comprehension as well as production. Together, these results question the notion of a left-dominant network of brain regions for language processing. (shrink)

The purpose of this paper is to explore the question whether and in what sense emotions might be said to provide reasons for actions or to rationalize them. This requires that one have a picture of the causal structure of actions that is sufficiently detailed for one to see how emotions can impinge on the proc-ess of action production. I present a two-tiered model of action explanation and try to exploit this model in a tentative account of the modes of (...) in-volvement of emotions in the explanation of action. In particular, I examine in what sense emotions can be said not just to explain actions, but also to rationalize them. (shrink)

Contemporary research on action-perception coupling draws on Gibson's concept of affordances. The text outlines the conceptual basis of this issue, showing how the notion of affordance is embraced in the theory of perception, understood as an active search for structured information that could improve the functioning of the organism in the environment. It also mentions a philosophical parallel (Martin Heidegger's philosophy of tools) and concludes that the intuitions behind the concept of affordances have been more inspiring to cognitive scientists, neuroscientists (...) and researchers in robotics than to psychologists studying perception. (shrink)

I discuss the relations between the phenomenon of inattentional blindness and neuropsychological syndromes such as visual neglect, extinction and simultanagnosia. While there are similarities in the types of unconscious processing apparent in inattentional blindness and in these syndromes, there are also differences - for instance, grouping affects the reportability of stimuli in some neuropsychological syndromes but not necessarily in inattentional blindness. The reasons for such discrepancies, and the link between unconscious processing and underlying neural structures are discussed.

Human vision raises a number of puzzles. Among them are the puzzles of visual experience: how to provide a scientific understanding of the phenomenal character of the visual experiences of the shapes, textures, colors, orientations and motion of perceived objects? How can a purely subjective visual experience be the basis of so much objective knowledge of the world? Visually guided actions raise a different puzzle: how can actions directed towards a target be so accurate in the absence of the agent’s (...) awareness of many of the target’s visual attributes? Ways of Seeing has three related goals, the first of which is to make the case for a broadly representational approach to the above set of puzzles. The second goal of WoS is to argue that the version of the ‘two-visual systems’ model of human vision best supported by the current empirical evidence has the resources to solve the puzzle of visually guided actions, which has been at the center of much recent work in the cognitive neuroscience of vision and action. The third goal of WoS is to draw attention to some of the tensions between acceptance of the two-visual systems model of human vision and some influential views about the nature and function of the content of visual experience espoused by philosophers in response to the puzzles raised by visual experience. (shrink)

One's contemporaneous conscious mental states seem bound in a single, unified experience. Dainton argues, against what he calls the S-Thesis, that we cannot explain such co-consciousness in terms of states' being located in a single phenomenal space, a functional space posited to explain our ability to locate ourselves relative to perceived stimuli. But Dainton's argument rests on a conflation of egocentric and allocentric self-localizing, and thus fails to undermine the S-Thesis. Nevertheless, experiments on visual neglect suggest one can have unconscious (...) mental states that are located in the same phenomenal field, so the S-Thesis fails after all. I examine a modified version of the S-Thesis according to which mental states are co-conscious when one is aware of them via a higher-order sensation that represents them as located in the same phenomenal field. But among other problems, this view fails to explain the co-consciousness of intentional states, which aren't located in phenomenal fields. Finally, I argue that a higher-order-thought model of consciousness best explains the apparent unity of experience in terms of one's tacit assumption that all the first-person thoughts in virtue of which one is conscious of one's mental states refer to the same individual. (shrink)

We analysed location priming effects, and thus the ability to integrate visual information across subsequent trials in the three studies presented in the following chapters. Based on previous findings in healthy subjects priming effects occur under conditions that require no attentional shifts in-between subsequent trials, i.e. with the subject’s fixation maintained and the search displays presented at retinotopically equal locations with respect to the fixation cross. In study 1 we tested whether location-based priming effects would outlive spatial shifts of attention (...) in healthy subjects. The basic assumption, derived from Pisella and Mattingley´s account was they would, and that the outliving would be based on intact spatial remapping mechanisms operating in healthy subjects along with attention shifts. The aim of study 1 in view of further investigations in patients, i.e. in studies 2 and 3 was to test the suitability of the priming paradigm to serve our purpose to investigate spatial remapping abilities, and furthermore, in patients, purported deficits. To test whether priming effects would outlive saccadic shifts of overt attention, subjects had to re-fixate the fixation cross in turns on the left and on the right side of the monitor between subsequent trials. In two separate experiments priming effects were measured at post-saccadically retinotopic and spatiotopic locations, respectively, and compared to effects in a control experiment requiring no attention shifts. The experiments were also applied in study 2. To test whether priming effects would outlive covert shifts of attention subjects´ attention was distracted between subsequent trials while their fixation was maintained. In two separate experiments priming effects were measured after exogenous and endogenous distraction, respectively, and compared to a control experiment without distraction. The experiments were also applied in study 3. The presence of priming effects despite interfering attention shifts could be taken as evidence that processes that integrate visual information along with attention shifts, i.e. spatial remapping mechanisms, operate flawlessly in healthy subjects. The aim of study 2 was to test whether the parietal cortex provides the neural correlate of spatial remapping as assumed by Pisella and Mattingley. To that end, we tested whether spatial remapping deficits would occur after saccadic shifts of overt attention in patients with right parietal lesions. Deficits were expected to be indicated by altered or disturbed priming effects in those patients as compared to priming effects in healthy control subjects and furthermore, in patients with right-hemispheric lesions not involving the parietal lobe. Latter patients were tested, to control for and differentiate between deficits occurring more generally after right-hemispheric damages and specific deficits occurring after right parietal damages. Moreover, given the crucial role of priming for visual search disturbed priming as an indicator of deficient spatial remapping would provide support for the assumption made by Pisella and Mattingley that spatial remapping deficits contribute to visual search impairments as they are often observed in patients with right parietal lesions. The aim of study 3 was to test the model’s assumption that spatial remapping is required after spatial shifts of covert attention. Again, we compared priming effects of patients with right parietal lesions to those of patients with right-hemispheric lesions without parietal involvement, and healthy subjects. We expected priming effects to be disturbed in patients with right parietal lesions provided that covert attention shifts induce spatial remapping requirements, and that the anatomical site of spatial remapping mechanisms operating to integrate visual information across spatial shifts of covert attention is located in the parietal lobe. (shrink)

Recent experiments in normal subjects using neuroimaging demonstrate that the dorsal cortico-cortical pathway is involved during purely perceptual activities. Pathological cases with right posterior parietal lesions show deficits in visuospatial perception. It is argued that the radical dichotomy between perception and action pathways, as heralded in Milner and Goodale's book should be reexamined. The idea of distributed networks using resources in both visual pathways and recruited as a function of task demands is presented.

Milner and Goodale's work stands squarely at the centre of the debate on 'two cortical visual systems', and is often seen as offering a reinterpretation of the classic Ungerleider and Mishkin account of visual specialisation. Several 'problems' with this original account are presented, including reviewing the work in the context of the history of human neuropsychology. However, is argued that Milner and Goodale's reinterpretation offers much that is advantagous to our understanding of extra-striate cortical specialisation. In particular, the possible role (...) of the '3rd stream' is reviewed, including discussion of work which casts doubt the claim that object recognition is restricted exclusively to the ventral stream. Rather, the 3rd stream is presented as offering an optional visuo-spatial resource - which would be used for object recognition under non-optimal circumstances. Such an interpretation might offer a compromise between the two competing 'two visual systems' accounts. (shrink)

For over a century, drawing from observation, at least at the introductory level, has been integral to many secondary and most post-secondary art school programs in Europe and North America. Its place in such programs is understood to develop an ability to see and interpret on a flat surface the real, three-dimensional world; this skill, in turn, provides support to related mental processes such as memory, visualization, and imagination. Where an artist looks when drawing from observation may not be arbitrary (...) and can be observed, quantified, and analyzed. Our interest in examining the first few minutes of the drawing process takes its lead from the novice’s question, "Where should I begin?" Attempting to understand these first few minutes led to a collaborative study between art educators and cognitive-perceptual psychologists: the former interested in implications for practical pedagogy, the latter in applying expertise in eye movement and scientific methodology in service of a specific real-world question. The stated purpose of the study notwithstanding, contrasting histories and practices in art and science provided contexts for discussion beyond the collection and interpretation of data. This article seeks to report upon and further that discussion. (shrink)

In this paper, I shall offer a sketch of a dynamic theory of intentions. I shall argue that several categories or forms of intentions should be distinguished based on their different (and complementary) functional roles and on the different contents or types of contents they involve. I shall further argue that an adequate account of the distinctive nature of actions and of their various grades of intentionality depends on a large part on a proper understanding of the dynamic transitions among (...) these different forms of intentions. I also hope to show that one further benefit of this approach is to open the way for a more perspicuous account of the phenomenology of action and of the role of conscious thought in the production of action. (shrink)