Ecological and sensorimotor theories of perception build on the notion of action-dependent invariants as the basic structures underlying perceptual capacities. In this paper we contrast the assumptions these theories make on the nature of perceptual information modulated by action. By focusing on the question, how movement specifies perceptual information, we show that ecological and sensorimotor theories endorse substantially different views about the role of action in perception. In particular we argue that ecological invariants are characterized with reference to transformations produced (...) in the sensory array by movement: such invariants are transformation-specific but do not imply motor-specificity. In contrast, sensorimotor theories assume that perceptual invariants are intrinsically tied to specific movements. We show that this difference leads to different empirical predictions and we submit that the distinction between motor equivalence and motor-specificity needs further clarification in order to provide a more constrained account of action/perception relations. (shrink)

How do humans manage to keep track of a gradually changing object or person as the same persisting individual despite the fact that the extraction of information about this individual must often rely on heterogeneous information sources and heterogeneous tracking methods? The article introduces the Empirical Tracking of Individuals theory to address this problem. This theory proposes an analysis of the concept of integrated tracking, which refers to the capacity to acquire, store, and update information about the identity and location (...) of individuals in our environment. It hypothesizes that certain functions of attention are a key to explaining how the cognitive flexibility of the human mind overcomes the heterogeneity of sources and methods in integrated tracking. At least two premises lend support to this hypothesis. First, heterogeneity of tracking sources is overcome by the combination of information from multiple perceptual modalities and a phenomenon of multisensory 'transparency'. Second, heterogeneity of tracking sources and methods may also be overcome by inferences that combine information across domains to acquire reasons to believe propositions about the target's location and identity. (shrink)

One of the key challenges confronting cognitive science is to discover natural categories of cognitive function. Of special interest is the unity or diversity of cognitive control mechanisms. Evolutionary history is an underutilized resource that, together with neuropsychological and neuroscientific evidence, can help to provide a biological ground for the fractionation of cognitive control. Comparative evidence indicates that primate brain evolution has produced dissociable mechanisms for external action control and internal self-regulation, but that most real-world behaviors rely on a combination (...) of these. The archeological record further indicates the timing and context of distinctively human elaborations to these cognitive control functions, including the gradual emergence of increasingly complex hierarchical action control. (shrink)

Accurate perception of moving objects would be useful; accurate visually guided action is crucial. Visual motion across the scene influences perceived object location and the trajectory of reaching movements to objects. In this commentary, I propose that the visual system assigns the position of any object based on the predominant motion present in the scene, and that this is used to guide reaching movements to compensate for delays in visuomotor processing.

Evidence for motion extrapolation at motion offset is scarce. In contrast, there is abundant evidence that subjects mentally extrapolate the future trajectory of weak motion signals at motion offset. Further, pointing movements overshoot at motion offset. We believe that mental and sensorimotor extrapolation is sufficient to solve the problem of perceptual latencies. Both present the advantage of being much more flexible than motion extrapolation.

Artists, art critics, art historians, and cognitive psychologists have asserted that visual artists perceive the world differently than nonartists and that these perceptual abilities are the product of knowledge of techniques for working in an artistic medium. In support of these claims, Kozbelt (2001) found that artists outperform nonartists in visual analysis tasks and that these perceptual advantages are statistically correlated with drawing skill. We propose a model to explain these results that is derived from a diagnostic framework for object (...) recognition and recent research in cognitive neuroscience on selective visual attention. This research demonstrates that endogenous shifts of visual attention enhance the encoding of expected features in the visual field and inhibit the perception of potential distracters. Moreover, it demonstrates complementary roles for spatial schemata and motor plans in visual attention. We argue that artists develop novel spatial schemata, which enable them to recognize and reproduce stimulus features sufficient for adequate artistic production in a medium, and that these schemata become encoded as motor plans as artists develop technical proficiency in a medium. We hypothesize that artists' perceptual advantages can therefore, be explained by the role spatial schemata and motor plans play in selective attention. (shrink)

In contrast to Constructivist Views, which construe perceptual cognition as an essentially reconstructive process, this article recommends the Deictic View, which grounds perception in perceptual-demonstrative reference and the use of deictic tracking strategies for acquiring and updating knowledge about individuals. The view raises the problem of how sensory-motor tracking connects to epistemic and integrated forms of tracking. To study the strategies used to solve this problem, we report a study of the ability to track distal individuals when only their directions (...) can be perceived and not their locations. We introduce a new experimental paradigm named the 'Modified Traveling Salesman Problem' (MTSP), which requires subjects to visit n invisible targets in a 2D display once each. Surprisingly, subjects are competent at this task for up to 10 targets. We consider two types of tracking strategies that subjects might use: 'location-based' strategies and 'deictic direction-based' strategies. A number of observations suggest that subjects used the latter, at least for larger numbers of targets. We hypothesize that subjects used perceptual-demonstrative reference and deictic strategies (i) to perform the sensory-motor tracking of directional segments, (ii) to bind the segments with their updated status in the task, and (iii) to perform the epistemic tracking of invisible targets by means of perception-based inferences. (shrink)

The notion of conceptuality is still unclear and vague. I will present a definition of conceptual and nonconceptual representations that is grounded in different aspects of the representations’ structures. This definition is then used to interpret empirical results from human and animal navigation. It will be shown, that the distinction between egocentric and allocentric spatial representations can be matched onto the conceptual vs. nonconceptual distinction. The phenomena discussed in spatial navigation are thereby put into a wider context of cognitive abilities, (...) which allows for new explanations of certain features of spatial representations and how they are linked to other capacities, like perception and reasoning. (shrink)

I propose and defend the Allocentric-Egocentric Interface Theory of Con- sciousness. Mental processes form a hierarchy of mental representations with maxi- mally egocentric (self-centered) representations at the bottom and maximally allocentric (other-centered) representations at the top. Phenomenally conscious states are states that are relatively intermediate in this hierarchy. More speci.

_Consciousness, Color, and Content_ is a significant contribution to our understanding of consciousness, among other things. I have learned a lot from it, as well as Tye.

Can phenomenal consciousness be given a reductive natural explanation? Many people argue not. They claim that there is an.

Last year at VSS, Bullot, Droulez & Pylyshyn reported studies using a Modified Traveling Salesman Paradigm in which a virtual vehicle had to visit up to 10 targets once and only once, and in which the invisible targets were identified only by line segments pointing from the vehicle toward each target. We hypothesized that subjects used two distinct strategies: A “location-based strategy”, which kept track of where targets were located in screen coordinates, and a “segment-based strategy” that kept track of (...) which segments corresponded to visited targets. We report new studies that further explore these two strategies. Subjects passively observed a computer-controlled virtual vehicle that visited a number of targets. Two forms of display were used: an “Allocentric” display, in which the vehicle moved and the targets remained fixed in screen coordinates, and an “Egocentric” display, in which the vehicle's position on the screen remained fixed while the targets moved -- as if the environment were being viewed by an observer on the vehicle. At the end of each trial, the directional segments were extended to the edge of the screen and subjects were asked to perform two tasks by referring to these segments. In the “status task” observers had to indicate for each segment whether the corresponding target had been visited or not. In the “locating task” they had to locate each target along its directional segment. Performance on these two tasks measures the use of the two hypothesized strategies. Results showed that observers do well on the status task with 4 or 6 targets in both display conditions, but do poorly on the locating task, especially in the egocentric condition when there are more targets. These results are consistent with the hypothesis that in the egocentric condition the MTSP task is carried out primarily by segment-tracking, which can be viewed as a deictic strategy. (shrink)

Imitation, deliberation, and mindreading are characteristically human sociocognitive skills. Research on imitation and its role in social cognition is flourishing across various disciplines. Imitation is surveyed in this target article under headings of behavior, subpersonal mechanisms, and functions of imitation. A model is then advanced within which many of the developments surveyed can be located and explained. The shared circuits model (SCM) explains how imitation, deliberation, and mindreading can be enabled by subpersonal mechanisms of control, mirroring, and simulation. It is (...) cast at a middle, functional level of description, that is, between the level of neural implementation and the level of conscious perceptions and intentional actions. The SCM connects shared informational dynamics for perception and action with shared informational dynamics for self and other, while also showing how the action/perception, self/other, and actual/possible distinctions can be overlaid on these shared informational dynamics. It avoids the common conception of perception and action as separate and peripheral to central cognition. Rather, it contributes to the situated cognition movement by showing how mechanisms for perceiving action can be built on those for active perception.;>;>The SCM is developed heuristically, in five layers that can be combined in various ways to frame specific ontogenetic or phylogenetic hypotheses. The starting point is dynamic online motor control, whereby an organism is closely attuned to its embedding environment through sensorimotor feedback. Onto this are layered functions of prediction and simulation of feedback, mirroring, simulation of mirroring, monitored inhibition of motor output, and monitored simulation of input. Finally, monitored simulation of input specifying possible actions plus inhibited mirroring of such possible actions can generate information about the possible as opposed to actual instrumental actions of others, and the possible causes and effects of such possible actions, thereby enabling strategic social deliberation. Multiple instances of such shared circuits structures could be linked into a network permitting decomposition and recombination of elements, enabling flexible control, imitative learning, understanding of other agents, and instrumental and strategic deliberation. While more advanced forms of social cognition, which require tracking multiple others and their multiple possible actions, may depend on interpretative theorizing or language, the SCM shows how layered mechanisms of control, mirroring, and simulation can enable distinctively human cognitive capacities for imitation, deliberation, and mindreading. (shrink)

In Western common sense, one speaks of there being five human senses, a claim apparently challenged by the biological and psychological sciences. Part of this challenge comes in the form of claiming the existence of additional senses. Part of the challenge comes from positing multiple senses where common sense only speaks of one, such as with the fractionation of “touch” into pressure and temperature senses. One conceptual difficulty in thinking about the number and division of senses is that it's not (...) clear whether the different senses constitute natural kinds and, if not, what kind of kind they are. Should we favor antirealism with respect to the senses, akin to the arguments of some concerning the nature of species or race? I will argue that this first problem is compounded by another: that we ought to be pluralists with respect to the senses—what is meant by the term “sense” varies from context to context, varying even between scientific contexts. (shrink)

By characterizing the function of the ventral and dorsal visual streams as, respectively, vision-for-perception and vision-for-action, Milner and Goodale have brought some action onto the perceptual scene. However, with the distinction of the ventral "what" system and the dorsal "how" system, comes a dilemma: How is the operation of the two systems united toward common goals? This is an example of a binding problem. We propose that for binding these two systems, no mechanism needs to exist in the brain to (...) bring ventral and dorsal representations together. Coherent behavior may be accomplished by focusing the two streams upon the same external object through a strategy of spatial selection, using either the fovea or selective attention. This strategy exploits the simple fact that two objects cannot occupy the same place at the same time. Other kinds of binding, like that involving the perceptual binding of the elements of a scene into coherent perceptual units, may be accomplished by exploiting other regularities of the environment, such as the likelihood that two simultaneous sounds were caused by a common event. From an evolutionary perspective, the most effective way to cope with the distant environment is to use different but complementary sensors, both contributing to aspects of identification and action guidance. For example, audition plays a role both in perceptual analysis and in action guidance, suggesting the possibility of segregated processing of auditory information. Thus, the functional distinction between a "what" system and a "how" system may not be limited to the visual modality, but may be a fundamental distinction for behavioral control in general. (shrink)

Science seems generally to aim at truth. And governmental support of science is often premised on the instrumental value of truth in service of advancing our practical objectives, both as individuals and as communities, large and small. While there is some political expediency to this view, it is not correct. The value of truth is nowise that it helps us achieve our aims. In fact, just the contrary: truth deserves to be believed only on the condition that its claim upon (...) us is orthogonal to any utility it might have in the service of (any and all) practical ends. (shrink)

In this paper I aim to present an explanation of object permanence that is derived from an ecological account of perceptually based action. In understanding why children below a certain age do not search for occluded objects, one must first understand the process by which these children perform certain intentional actions on non-occluded items; and to do this one must understand the role affordances play in eliciting retrieval behaviour. My affordance-based explanation is contrasted with Shinskey and Munakata's graded representation account; (...) and although I do not reject totally the role representations play in initiating intentional action I nevertheless maintain that only by incorporating direct perception into an account of object permanence can a fuller understanding of this phenomenon be achieved. (shrink)

This paper concerns local yet systematic problems of contrastive underdetermination of model choice in cognitive neuroscience debates about the so-called two visual systems hypothesis. The underdetermination problem is systematically generated by the way certain assumptions about the representationalist nature of computation are translated into experimental practice. The problem is that behavioural data underdetermine the choice between competing representational models. In this paper, I diagnose how these assumptions generate underdetermination problems in the choice between competing functional models of perception–action. Using the (...) tools of philosophy of science, I describe the type of underdetermination and sketch a possible cure. (shrink)

Functionalism is widely regarded as the central doctrine in the philosophy of cognitive science, and is invoked by philosophers of cognitive science to settle disputes over methodology and other puzzles. I describe a recent dispute over extended cognition in which many commentators appeal to functionalism. I then raise an objection to functionalism as it figures in this dispute, targeting the assumption that generality and abstraction are tightly correlated. Finally, I argue that the new mechanist framework offers more realistic resources for (...) understanding cognitive science, and hence is a better source of appeal for resolving disagreement in philosophy of science. (shrink)

Viewing emotion from an evolutionary perspective, researchers have argued that simple responses to affective stimuli can be triggered without mediation of cognitive processes. Indeed, findings suggest that positively and negatively valenced stimuli trigger approach and avoidance movements automatically. However, affective stimulus–response compatibility phenomena share so many central characteristics with nonaffective stimulus–response compatibility phenomena that one may doubt whether the underlying mechanisms differ. We suggest an “affectively enriched” version of the theory of event coding (TEC) that is able to account for (...) both affective and nonaffective compatibility, and that can account for the observation that both types of compatibility seem to be modulated by goals and intentions. Predictions from the model are tested in an experiment where participants carried out approach and avoidance responses to either the valence or the orientation of emotionally charged pictures. Under affective instruction the positive-approach/negative-avoid mapping yielded faster responses than the positive-avoid/negative-approach mapping, but no such effect was observed under spatial instruction. Conversely, spatial compatibility effects were obtained under spatial, but not under affective instruction. We conclude that affective and nonaffective compatibility effects reflect the same mechanism. (shrink)

The current paper argues for synchronising spatial frames of reference for achieving effective multiparty communication in collaborative virtual environments. Synchronising nonverbal behaviour from different modalities is an important step for simulating face-to-face-interaction where all nonverbal cues are available. Such synchronisation also serves as an effective basis for building multimodal interfaces especially if these have to be deployed for multiparty communication. It is argued that common spatial reference frames are helpful in coordinating different points of attention and facilitating work by serving (...) as the springboard for joint attention among members of the team. Consequently, it is desirable to aim for such common grounds and not just focus on coordinating disjointed virtual spaces for facilitating decision-making by reducing felt collaborative effort. Implementing the synchronisation of spatial reference frames for modern technologies thus serves dual purposes by achieving common grounds in communication and maintaining autonomy of each member at the same time. Towards this end, the current paper proposes the concept of decentred egocentric frame, the origin of which is one’s own body and the spatial relation between two objects is defined with respect to this origin. This frame seems to be important for separating each member’s focus from his own body (self/activities) and also helps in coordinating one’s focus with those of the others whether interacting verbally or nonverbally. This is an important conceptual development as the proposed classification is hypothesised to function in a similar manner across different sensory modalities. The paper concludes with issues on implementation and other future conceptual developments. (shrink)

The problem of controlling an artificial general intelligence has fascinated both scientists and science-fiction writers for centuries. Today that problem is becoming more important because the time when we may have a superhuman intelligence among us is within the foreseeable future. Current average estimates place that moment to before 2060. Some estimates place it as early as 2040, which is quite soon. The arrival of the first AGI might lead to a series of events that we have not seen before: (...) rapid development of an even more powerful AGI developed by the AGIs themselves. This has wide-ranging implications to the society and therefore it is something that must be studied well before it happens. In this paper we will discuss the problem of limiting the risks posed by the advent of AGIs. In a thought experiment, we propose an AGI which has enough human-like properties to act in a democratic society, while still retaining its essential artificial general intelligence properties. We discuss ways of arranging the co-existence of humans and such AGIs using a democratic system of coordination and coexistence. If considered a success, such a system could be used to manage a society consisting of both AGIs and humans. The democratic system where each member of the society is represented in the highest level of decision-making guarantees that even minorities would be able to have their voices heard. The unpredictability of the AGI era makes it necessary to consider the possibility that a population of autonomous AGIs could make us humans into a minority. (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)

According to direct perception approaches we directly see others’ emotions, and by seeing emotions we immediately ascribe them to others. Direct perception is explicitly presented as an alternative account of mindreading, but it also contains an implicit thesis about the extent of the reach of perception. In this paper emotion perception is defended: siding with the direct perception approach I claim that we can simply see emotions and not just low level features of the facial and bodily displays, but contra (...) the direct perception approach I argue that seeing emotions is not sufficient for recognizing emotions as mental states in order to ascribe them to others. (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)

Influential theories on affect and emotion propose a fundamental differentiation between emotion and cognition, and research paradigms designed to test them focus on differences rather than similarities between affective and cognitive processes. This research orientation is increasingly challenged by the widespread and successful use of cognitive research paradigms in the study of affect and emotion—a challenge with far-reaching implications. Where and on what basis should theorists draw the line between cognition and emotion, and when is it useful to do so? (...) Should researchers build more global, integrative models of cognition and emotion, or should they rely on local, content-specific models that draw attention to a differentiation between affective and cognitive processes? This special issue compiles different viewpoints on fundamental issues in the relationship between affect and cognition. (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)

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)

Milner and Goodale's influential theory of visual processing suggests that only the ventral stream is directly associated with explicit conscious experience. However the implicit/explicit distinction does not map clearly onto the two visual streams. Whilst there is good evidence for the non-conscious nature of dorsal stream processing, evidence suggests that substantial processing in the ventral stream also occurs in the absence of conscious awareness. An alternative view is considered in which it is assumed that conscious awareness is not a property (...) of specific processing systems but where there exists a single conscious awareness system capable of interacting with the various processing streams. (shrink)

Our target article proposed that language production and comprehension are interwoven, with speakers making predictions of their own utterances and comprehenders making predictions of other people's utterances at different linguistic levels. Here, we respond to comments about such issues as cognitive architecture and its neural basis, learning and development, monitoring, the nature of forward models, communicative intentions, and dialogue.

This is a summary of the book Ways of Seing co-authord witth Marc Jeannerod and published by Oxford University Press in 2003.

The Bayesian model of multisensory cue integration proposed by Ernst and Banks provides an attractive model for understanding a way that our sensory systems may interact. Moreover, it has been suggested that the process of multisensory integration that it models underpins conscious experiences with multisensory representational contents merged across modalities. Should we therefore take empirical support for the Bayesian model as evidence of the multimodality of perception? Focusing on evidence of integration across vision and touch, I argue that apparent support (...) for the model does not warrant the rejection of the view that each of our conscious perceptual experiences is associated with one and only one sense modality. (shrink)

In this paper we offer a theory of cross-modal objects. To begin, we discuss two kinds of linkages between vision and audition. The first is a duality. The the visual system detects and identifies surfaces ; the auditory system detects and identifies sources . Surfaces are illuminated by sources of light; sound is reflected off surfaces. However, the visual system discounts sources and the auditory system discounts surfaces. These and similar considerations lead to the Theory of Indispensable Attributes that states (...) the conditions for the formation of gestalts in the two modalities. The second linkage involves the formation of audiovisual objects, integrated cross-modal experiences. We describe research that reveals the role of cross-modal causality in the formation of such objects. These experiments use the canonical example of a causal link between vision and audition: a visible impact that causes a percussive sound. (shrink)

The concept of action is playing an increasingly prominent role in attempts to explain how subjects can represent the world. The idea is that at least some of the role traditionally assigned to internal representations can, in fact, be played by the ability of subjects to act on the world, and the exercise of that ability on appropriate occasions. This paper argues that the appeal to action faces a serious dilemma. If the concept of action employed is a representational one, (...) then the appeal to action is circular: representation has been presupposed rather than explained. However, if the concept of action employed is a non-representational one, then the appeal to action will be inadequate: in particular, the appeal will fail to account for the normativity of representation. The way out of this dilemma is to develop a conception of action that is normative, but where this normativity is not inherited from the action's connection to distinct representational states. The normative status of such actions would be sui generis. This paper argues that such a conception of action is available. (shrink)

Recent literature have underlined the connections between children’s reading skills and capacity to create and use mental representations or mental images; furthermore data highlighted the involvement of visuospatial abilities both during math learning and during subsequent developmental phases in performing math tasks. The present research adopted a longitudinal design to assess whether the processes of mental imagery in preschoolers (ages 4–5 years) are predictive of mathematics skills, writing and reading, in the early years of primary school (ages 6–7 years). The (...) research lasted for two school years; in the first phase, the general group of participants consisted of 100 children, and although all participants agreed to be part of the research, in the second phase, there was a mortality rate of 30%. In order to measure school learning and mental imagery processes four batteries of tests were used. The mental imagery battery evaluated mental generation, inspection and transformation processes. Data underlined that the different aspects in which mental imagery processes are articulated are differently implied in some skills that constitute school learning. These findings emphasise the potential usefulness of a screening for mental imagery ability for schoolchildren to adopt effective measures to increase their mental imagery abilities. (shrink)

La concepción fenomenológica del sentido común inspirada por James sostiene que atender es esencialmente un fenómeno mental consciente. Las implicancias filosóficas modales de esta tesis sobre la naturaleza de la atención son claras. No es posible atender una cosa, sin ser consciente de ella. Sobre la base de estudios clásicos en torno a patologías visuales como la vista ciega y a experimentos recientes con sujetos no patológicos, este artículo argumenta que la conclusión filosófica jamesiana acerca de la metafísica de la (...) atención es falsa. La evidencia sugiere que de hecho es posible atender objetos sin experimentarlos conscientemente. (shrink)

The present empirical study investigates limitations of human visual working memory. The experiments of the present work involve the experimental paradigm of change detection using simple geometrical objects in the form of rectangles of different colour, length, and orientation. It can be shown, that a limited performance in the temporary storage of visual information has multiple sources. Limitations of VWM can be attributed to a limited capacity or a limited duration, but also to limitations in retrieval, which so far has (...) found only little attention. Key findings of the present study show, that a capacity limitation cannot be described by a simple and generally valid size of the store. It is in fact generally acknowledged that the capacity limitation of VWM is object-based, which means that the capacity can roughly be determined by the number of visual objects. However, it could be shown that the complexity of the objects has an influence on memory performance: Experimental evidence shows, e.g., that memory performance decreases, when an object is characterized not only by one feature, but by a number of features. The results are explained by increased storage demands for the binding of the features. Other key findings of the present study relate to the process of retrieval of information from VWM. For example, an asymmetric performance pattern could be observed: In a change detection task a memory performance was observed that corresponds to a capacity of 3 - 4 objects. In contrast a drastic decrease of performance corresponding to a capacity of only 1 object was observed, when the task was to find a matching item among changed distractors. These results lead to the idea of a change signal, by which the empirical data can be explained. The change signal is elicited by a local mismatch between the information stored in VSTM and perceptual online information. The retrieval process is efficient, when the change signal can be used in the memory task. However, retrieval is extremely limited, when in the presence of multiple changes a less efficient strategy has to be applied. In the course of the present study, moreover, it became evident that there are various links between VWM processes and visual attention. Visual attention is probably crucial for feature binding in VWM. In retrieval the change signal probably involves mechanisms of visual attention. The present study could, therefore, contribute to a clarification of the relation between VWM and visual attention. (shrink)