This article probes the visual spatial représentations underlying the creative conceptual design of complex objects.

Neuropsychological findings used to motivate the "two visual systems" hypothesis have been taken to endanger a pair of widely accepted claims about spatial representation in conscious visual experience. The first is the claim that visual experience represents 3-D space around the perceiver using an egocentric frame of reference. The second is the claim that there is a constitutive link between the spatial contents of visual experience and the perceiver's bodily actions. In this paper, I (...) review and assess three main sources of evidence for the two visual systems hypothesis. I argue that the best interpretation of the evidence is in fact consistent with both claims. I conclude with some brief remarks on the relation between visual consciousness and rational agency. (shrink)

Is vision informationally encapsulated from cognition or is it cognitively penetrated? I shall argue that intentions penetrate vision in the experience of visual spatial constancy: the world appears to be spatially stable despite our frequent eye movements. I explicate the nature of this experience and critically examine and extend current neurobiological accounts of spatial constancy, emphasizing the central role of motor signals in computing such constancy. I then provide a stringent condition for failure of informational encapsulation that (...) emphasizes a computational condition for cognitive penetration: cognition must serve as an informational resource for visual computation. This requires proposals regarding semantic information transfer, a crucial issue in any model of informational encapsulation. I then argue that intention provides an informational resource for computation of visual spatial constancy. Hence, intention penetrates vision. (shrink)

Context: In sciences of the mind, cognitive phenomena are typically investigated with the use of psychological tasks. These usually represent highly constrained environments that isolate and make ….

Take a moment to use mental imagery to perform the following tasks: (1) decide whether an apple is more similar in shape to a banana or an orange, (2) determine how to rearrange the furniture in your bedroom to make room for a new dresser, and (3) drive home during rush hour. Although we take our ability to perform tasks such as these for granted, they raise a host of interesting questions about imagery. For instance, what is the relationship between (...) imagery and perception? What types of processes are needed to account for our ability to generate, maintain, transform, and inspect images? How do we characterize individual differences in imagery ability? What is the relation between imagery and spatial representation? What can we do with mental imagery? This essay will focus on visual imagery, because we know more about visual imagery than auditory, haptic, gustatory, or olfactory imagery. The expectation is that many principles, although not all details, of emerging theory will be applicable to imagery in other modes. (shrink)

Five experiments investigated the role of spatial connectedness between a pair of objects presented in the change detection task for the actual capacity of visual working memory (VWM) in healthy young adults (total N = 405). Three experiments yielded a surprising nonlinear relationship between the proportion of pair-wise connected objects and capacity, with the highest capacity observed for homogenous displays, when either all objects were connected or disjointed. A drop in capacity, ranging from an average of a quarter (...) of an object out of three objects maintained in VWM, was noted when only some objects were connected while others were disjointed. As indicated by another two experiments, this effect was specific to double-feature encoding, but disappeared when single visual features had to be memorized. No existing theoretical model of VWM can directly explain this novel effect. Overall, the nonlinear effect of spatial connectedness implies that representations in VWM possess hierarchical structure defined by wholes, parts, features, and their relations, and the heterogeneity of such a structure hinders VWM performance, while homogeneity facilitates it. (shrink)

Visual space can be distinguished from physical space. The first is found in visual experience, while the second is defined independently of perception. Theorists have wondered about the relation between the two. Some investigators have concluded that visual space is non-Euclidean, and that it does not have a single metric structure. Here it is argued that visual space exhibits contraction in all three dimensions with increasing distance from the observer, that experienced features of this contraction are (...) not the same as would be the experience of a perspective projection onto a fronto-parallel plane, and that such contraction is consistent with size constancy. These properties of visual space are different from those that would be predicted if spatial perception resulted from the successful solution of the inverse problem. They are consistent with the notion that optical constraints have been internalized. More generally, they are also consistent with the notion that visual spatial structures bear a resemblance relation to physical spatial structures. This notion supports a type of representational relation that is distinct from mere causal correspondence. The reticence of some philosophers and psychologists to discuss the structure of phenomenal space is diagnosed in terms of the simple materialism and the functionalism of the 1970s and 1980s. (shrink)

Many scientific discoveries have depended on external diagrams or visualizations. Many scientists also report to use an internal mental representation or mental imagery to help them solve problems and reason. How do scientists connect these internal and external representations? We examined working scientists as they worked on external scientific visualizations. We coded the number and type of spatial transformations (mental operations that scientists used on internal or external representations or images) and found that there were a very (...) large number of comparisons, either between different visualizations or between a visualization and the scientists’ internal mental representation. We found that when scientists compared visualization to visualization, the comparisons were based primarily on features. However, when scientists compared a visualization to their mental representation, they were attempting to align the two representations. We suggest that this alignment process is how scientists connect internal and external representations. (shrink)

Evidence for a dichotomy between the planning of an action and its on-line control in humans is reviewed. This evidence suggests that planning and control each serve a specialized purpose utilizing distinct visual representations. Evidence from behavioral studies suggests that planning is influenced by a large array of visual and cognitive information, whereas control is influenced solely by the spatial characteristics of the target, including such things as its size, shape, orientation, and so forth. Evidence from (...) brain imaging and neuropsychology suggests that planning and control are subserved by separate visual centers in the posterior parietal lobes, each constituting part of a larger network for planning and control. Planning appears to rely on phylogenetically newer regions in the inferior parietal lobe, along with the frontal lobes and basal ganglia, whereas control appears to rely on older regions in the superior parietal lobe, along with the cerebellum. Key Words: action; apraxia; control; illusions; optic ataxia; PET; planning; reaching;. (shrink)

Previous studies have explored the effects of attention on spatial representation. Specifically, in the attentional repulsion effect, a transient visual cue that captures attention has been shown to alter the perceived position of a target stimulus to the direction away from the cue. The effect is also susceptible to retrospective influence, that attention appears to attract the target when the cue appears afterwards. This study examined the necessity of visual awareness of the cue in these phenomena. We (...) found that when the cues were rendered invisible by backward visual masks, both repulsion and attraction effects were weakened but still observed. The results suggest that the effects possibly depend on processes that are not necessarily associated with conscious visual awareness of the cues. We conjecture that attentional shift produced by the weak, invisible cues may play a role in spatial distortion; but other possible accounts including non-attentional ones are also discussed. (shrink)

Spatial memory relies on encoding, storing, and retrieval of knowledge about objects’ positions in their surrounding environment. Blind people have to rely on sensory modalities other than vision to memorize items that are spatially displaced, however, to date, very little is known about the influence of early visual deprivation on a person’s ability to remember and process sound locations. To fill this gap, we tested sighted and congenitally blind adults and adolescents in an audio-spatial memory task inspired (...) by the classical card game “Memory.” In this research, subjects had to find pairs among sounds displaced on an audio-tactile device composed of loudspeakers covered by tactile sensors. To accomplish this task, participants had to remember the spatialized sounds’ position and develop a proper mental spatial representation of their locations. The test was divided into two experimental conditions of increasing difficulty dependent on the number of sounds to be remembered. Results showed that sighted participants outperformed blind participants in both conditions. Findings were discussed considering the crucial role of visual experience in properly manipulating auditory spatial representations, particularly in relation to the ability to explore complex acoustic configurations. (shrink)

There is a long-lasting quest of demarcating a minimally representational behavior. Based on neurophysiologically-informed behavioral studies, we argue in detail that one of the simplest cases of organismic behavior based on low-resolution spatial vision–the visually-guided obstacle avoidance in the cubozoan medusaTripedalia cystophora–implies already a minimal form of representation. We further argue that the characteristics and properties of this form of constancy-employing structural representation distinguish it substantially from putative representational states associated with mere sensory indicators, and we reply to some (...) possible objections from the liberal representationalists camp by defending and qualitatively demarcating the minimal nature of our case. Finally, we briefly discuss the implications of our thesis within a naturalistic framework. (shrink)

The public transport sector in the urban landscape in Nigeria is a prominent social site for the spatial distribution of automobile graffiti signatures. Transporters have various kinds of symbolic tags on their vehicles that convey different messages which represent their local attitudes, beliefs, religious identities, folk psychology, and safety precautionary measures to recipients (other road users and passers-by). This article, based on two case studies, examines the practice of automobile graffiti on trucks and lorries in Calabar metropolis, Cross River (...) State, south-eastern Nigeria. It investigates the motivations, thematic categories, and subjective semiotic interpretations of these verbal signatures from the perspectives of visual semiotics theory using participant observations, semi-structured interviews, and informal conversations. The study demonstrates that truck drivers/owners use their vehicles as visible artistic platforms in the public space to express their thoughts and sentiments on personal, social, and religious issues affecting the society. The study concludes that these inscriptions and imageries are artistic subcultures that mirror wide ranging value categories and provide outlets for spatial transformation, creative agencies, and social commentaries. (shrink)

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)

The posterior parietal cortex and frontal eye field contain maps of visual salience on which the decision to choose a saccade may be based. However, an averaging express saccade is not represented by a victorious unimodal representation in the superior colliculus. Normalization as described by Findlay & Walker is not necessary for the generation of saccades.

We are highly tuned to each other's visual attention. Perceiving the eye or hand movements of another person can influence the timing of a saccade or the reach of our own. However, the explanation for such spatial orienting in interpersonal contexts remains disputed. Is it due to the social appearance of the cue—a hand or an eye—or due to its social relevance—a cue that is connected to another person with attentional and intentional states? We developed an interpersonal version (...) of the Posner spatial cueing paradigm. Participants saw a cue and detected a target at the same or a different location, while interacting with an unseen partner. Participants were led to believe that the cue was either connected to the gaze location of their partner or was generated randomly by a computer (Experiment 1), and that their partner had higher or lower social rank while engaged in the same or a different task (Experiment 2). We found that spatial cue‐target compatibility effects were greater when the cue related to a partner's gaze. This effect was amplified by the partner's social rank, but only when participants believed their partner was engaged in the same task. Taken together, this is strong evidence in support of the idea that spatial orienting is interpersonally attuned to the social relevance of the cue—whether the cue is connected to another person, who this person is, and what this person is doing—and does not exclusively rely on the social appearance of the cue. Visual attention is not only guided by the physical salience of one's environment but also by the mental representation of its social relevance. (shrink)

The importance of working memory in reading and mathematics performance has been widely studied, with recent research examining the components of WM and their roles in these educational outcomes. However, the differing relationships between these abilities and the foundational skills involved in the development of reading and mathematics have received less attention. Additionally, the separation of verbal, visual and spatial storage and processing and subsequent links with foundational skills and downstream reading and mathematics has not been widely examined. (...) The current study investigated the separate contributions of processing and storage from verbal, visual and spatial tasks to reading and mathematics, whilst considering influences on the underlying skills of verbal comprehension and counting, respectively. Ninety-two children aged 7- to 8-years were assessed. It was found that verbal comprehension was predicted by verbal storage and reading was predicted by verbal and spatial storage. Counting was predicted by visual processing and storage, whilst mathematics was related to verbal and spatial storage. We argue that resources for tasks relying on external representations of stimuli related mainly to storage, and were largely verbal and spatial in nature. When a task required internal representation, there was a draw on visual processing and storage abilities. Findings suggest a possible meaningful separability of types of processing. Further investigation of this could lead to the development of an enhanced WM model, which might better inform interventions and reasonable adjustments for children who struggle with reading and mathematics due to WM deficits. (shrink)

According to “actionism” (Noë 2010), perception constitutively depends on implicit knowledge of the way sensory stimulations vary as a consequence of the perceiver’s self-movement. My aim in this contribution is to develop an alternative conception of the role of action in perception present in the work of Gareth Evans using resources provided by Ruth Millikan’s biosemantic theory of mental representation.

This paper describes a programmatic theory of a process in early vision called indexing. The theory hypothesizes that a small number of primitive indexes are available for individuating, tracking and providing direct access to salient visual objects. We discuss some empirical and theoretical arguments in favor of the proposed index as a resource-limited link between an internal visual representation and objects in the visual world. We argue that this link is needed to explain a large range of (...) properties of vision, including the ability to simultaneously track multiple moving objects, to select a subset of visual items to process, as well as such larger issues as how mental images get their apparent metrical properties and why the world appears stable despite constant retinal motion. (shrink)

We present a general cognitive architecture that tightly integrates symbolic, spatial, and visual representations. A key means to achieving this integration is allowing cognition to move freely between these modes, using mental imagery. The specific components and their integration are motivated by results from psychology, as well as the need for developing a functional and efficient implementation. We discuss functional benefits that result from the combination of multiple content-based representations and the specialized processing units associated with (...) them. Instantiating this theory, we then discuss the architectural components and processes, and illustrate the resulting functional advantages in two spatially and visually rich domains. The theory is then compared to other prominent approaches in the area. (shrink)

The problem of representing the spatial structure of images, which arises in visual object processing, is commonly described using terminology borrowed from propositional theories of cognition, notably, the concept of compositionality. The classical propositional stance mandates representations composed of symbols, which stand for atomic or composite entities and enter into arbitrarily nested relationships. We argue that the main desiderata of a representational system—productivity and systematicity—can (indeed, for a number of reasons, should) be achieved without recourse to the (...) classical, proposition‐like compositionality. We show how this can be done, by describing a systematic and productive model of the representation of visual structure, which relies on static rather than dynamic binding and uses coarsely coded rather than atomic shape primitives. (shrink)

The problem of representing the spatial structure of images, which arises in visual object processing, is commonly described using terminology borrowed from propositional theories of cognition, notably, the concept of compositionality. The classical propositional stance mandates representations composed of symbols, which stand for atomic or composite entities and enter into arbitrarily nested relationships. We argue that the main desiderata of a representational system — productivity and systematicity — can (indeed, for a number of reasons, should) be achieved (...) without recourse to the classical, proposition-like compositionality. We show how this can be done, by describing a systematic and productive model of the representation of visual structure, which relies on static rather than dynamic binding and uses coarsely coded rather than atomic shape primitives. (shrink)

Everyday visual experience constantly confronts us with things we can interact with in the real world. We literally feel the outside presence of physical objects in our environment via visual perceptual experience. The visual feeling of presence is a crucial feature of vision that is largely unexplored in the philosophy of perception, and poorly debated in vision neuroscience. The aim of this article is to investigate the feeling of presence. I suggest that visual feeling of presence (...) depends on the visual representation of a very particular spatial relation with the object we interact with: the visual representation of absolute egocentric depth, which is due to stereoscopic vision. (shrink)

In the final scene of Michel Tournier’s postcolonial novel La Goutte d’or, the protagonist, Idriss, shatters the glass of a Cristobal & Co. storefront window while operating a jackhammer in the working-class Parisian neighbourhood on the Rue de la Goutte d’or. Glass fragments fly everywhere as the Parisian police arrive. In La Goutte d’or, Tournier explores the identity construction of Idriss through a discussion of the role that visual images play in the development of a twentieth-century consciousness of the (...) “Other.” At the beginning of the novel, a French tourist takes a photograph of Idriss during her visit to the Sahara. The boy’s quest to reclaim his stolen image leads him from the Sahara to Marseille, and finally to the Rue de la Goutte d’or in Paris. The Rue de la Goutte d’or remains one the most cosmopolitan neighbourhoods of the city. In Tournier’s novel, the goutte d’or also corresponds to a symbolic object: a Berber jewel. It is the jewel that Idriss brings with him, but which he also subsequently loses upon his arrival in Marseille. From the very moment that the French tourist photographs him, a marginalization of Idriss’s identity occurs. Marginality, quite literally, refers to the spatial property of a location in which something is situated. Figuratively speaking, marginality suggests something that is on the edges or at the outer limits of social acceptability. In this essay, I explore the construction of the marginalized postcolonial self through an examination of the function of visual representation in the development of a postcolonial identity in La Goutte d’or. In the end, I conclude that the construction of a postcolonial identity is based upon fragmentation and marginalization, which ultimately leads its subject to create an identity based upon false constructions. (shrink)

This article attempts to establish analogies between the recent introduction into architectural thought of notions such as the human body movement, events and scenarios, and the development of navigation and interaction principles and conventions in the computer world. The study of the human–computer interface contributes to an understanding of the major role of the computer screen as a point of convergence of different representational forms, and the emergence of new ones belonging to the digital culture. The compositional structure of interactive (...) multimedia works is on the one hand a visual, spatial composition and on the other a narrative and navigational structure. (shrink)

Everyday visual experience constantly confronts us with things we can interact with in the real world. We literally feel the outside presence of physical objects in our environment via visual perceptual experience. The visual feeling of presence is a crucial feature of vision that is largely unexplored in the philosophy of perception, and poorly debated in vision neuroscience. The aim of this article is to investigate the feeling of presence. I suggest that visual feeling of presence (...) depends on the visual representation of a very particular spatial relation with the object we interact with: the visual representation of absolute egocentric depth, which is due to stereoscopic vision. (shrink)

A fundamental question in visual neuroscience is: Why are the response properties of visual neurons as they are? A modern approach to this problem emphasizes the importance of adaptation to ecologically valid input, and it proceeds by modeling statistical regularities in ecologically valid visual input (natural images). A seminal model was linear sparse coding, which is equivalent to independent component analysis (ICA), and provided a very good description of the receptive fields of simple cells. Further models based (...) on modeling residual dependencies of the ‘‘independent” components have later been introduced. These models lead to emergence of further properties of visual neurons: the complex cell receptive fields, the spatial organization of the cells, and some surround suppression and Gestalt effects. So far, these models have concentrated on the response properties of neurons, but they hold great potential to model various forms of inference and learning. (shrink)

Cook (1995) criticizes the work of Jacobs and Kosslyn (1994) on spatial relations, shape representations, and receptive fields in neural network models on the grounds that first‐order correlations between input and output unit activities can explain the results. We reply briefly to Cook's arguments here (and in Kosslyn, Chabris, Marsolek, Jacobs & Koenig, 1995) and discuss how new simulations can confirm the importance of receptive field size as a crucial variable in the encoding of categorical and coordinate (...) class='Hi'>spatial relations and the corresponding shape representations; such simulations would testify to the computational distinction between the different types of representations. (shrink)

Despite the subjective experience of a continuous and coherent external world, we will argue that the perception and categorisation of visual space is constrained by the spatial resolution of the sensory systems but also and above all, by the pre-reflective representations of the body in action. Recent empirical data in cognitive neurosciences will be presented that suggest that multidimensional categorisation of perceptual space depends on body representations at both an experiential and a functional level. Results will (...) also be resumed that show that representations of the body in action are pre-reflective in nature as only some aspects of the pre-reflective states can be consciously experienced. Finally, a neuro-cognitive model based on the integration of afferent and efferent information will be described, which suggests that action simulation and associated predicted sensory consequences may represent the underlying principle that enables pre-reflective representations of the body for space categorisation and selection for action. (shrink)

The thresholds of human observers detecting line targets improve significantly when the targets are presented in a spatial context of collinear inducing stimuli. This phenomenon is referred to as spatial facilitation, and may reflect the output of long-range interactions between cortical feature detectors. Spatial facilitation has thus far been observed with luminance-defined, achromatic stimuli on achromatic backgrounds. This study compares spatial facilitation with line targets and collinear, edge-like inducers defined by luminance contrast to spatial facilitation (...) with targets and inducers defined by color contrast. The results of a first experiment show that achromatic inducers facilitate the detection of achromatic targets on gray and colored backgrounds, but tend to suppress the detection of chromatic targets. Chromatic inducers facilitate the detection of chromatic targets on gray and colored backgrounds, but tend to suppress the detection of achromatic targets. Chromatic spatial facilitation appears to be strongest when inducers and background are isoluminant. The results of a second experiment show that spatial facilitation with chromatic targets and inducers requires a longer exposure duration of the inducers than spatial facilitation with achromatic targets and inducers, which is already fully effective at an inducer exposure of 30 ms only. The findings point towards two separate mechanisms for spatial facilitation with collinear form stimuli: one that operates in the domain of luminance, and one that operates in the domain of color contrast. These results are consistent with neural models of boundary and surface formation which suggest that achromatic and chromatic visual cues are represented on different cortical surface representations that are capable of selectively attracting attention. Multiple copies of these achromatic and chromatic surface representations exist corresponding to different ranges of perceived depth from an observer, and each can attract attention to itself. Color and contrast differences between inducing and test stimuli, and transient responses to inducing stimuli, can cause attention to shift across these surface representations in ways that sometimes enhance and sometimes interfere with target detection. (shrink)

According to the received view in the philosophical literature on pictorial perception, when perceiving an object in a picture, we perceive both the picture’s surface and the depicted object, but the surface is only unconsciously represented. Furthermore, it is suggested, such unconscious representation does not need attention. This poses a crucial problem, as empirical research on visual attention shows that there can hardly be any visual representation, conscious or unconscious, without attention. Secondly, according to such a received view, (...) when looking at a picture aesthetically, one both consciously represents and visually attends to both the depicted object and the picture’s surface simultaneously. Thus, contra the empirical research on attention, only conscious visual representations are coupled, by such current view, with attention. And this clearly poses a second problem, as this philosophical account is not in tune with what vision science tells us about the functioning of our visual system. Furthermore, this raises another crucial problem, namely, that of explaining why aesthetic experience of pictures does not feel odd or conflicting, since, as previously noted in the philosophical literature, and contra the received view, if we are simultaneously consciously perceiving both the picture’s surface and the depicted object, there seems to be two things, at the same time, in the foreground of one’s visual consciousness. But, if so, as suggested, this would lead to a conflicting spatial visual experience. This paper offers a new description of the role of visual attention in picture perception, which explains the difference between the usual and the aesthetic way of perceiving a depicted object, without facing the problems reported above. A crucial role in our new account is played by the notion of unconscious attention, the distinction between focal and distributed, as well as top-down and bottom-up visual attention and the relationship between visual attention and visual consciousness. The paper, thus, offers the first theory concerning the exercise of visual attention in pictorial perception that is both philosophically rigorous and empirically reliable. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Reviewed by:Exploring Visual Culture: Definitions, Concept, ContextsPaul DuncumExploring Visual Culture: Definitions, Concept, Contexts, edited by Matthew Rampley. Edinburgh: Edinburgh University Press, 2005, 257 pp., $32.00 paper.I review this new introductory text in light of its competition as a textbook for undergraduates and as an introduction for graduate students. Other such texts include Barnard, Elkins, Mirzeoff, Walker and Chaplin, and Sturken and Cartwright,1 which appears to be the (...) most widely used. Rampley's anthology stands up well among these competitors, especially for those who wish to transition from art to contemporary popular visual culture rather more gently than other texts that, for many students, might come as too abrupt a disjuncture from mainstream practice in schools of art and design. As Matthew Rampley states in his excellent introduction, if the book has an original contribution to make, it is to situate an acknowledgment of traditional practices and issues into the makeup of visual culture studies. Unlike other texts, mentioned above, which tend to stress screen and print media, Rampley's agenda is to remind readers of the historical origins of many recent developments as well as the contribution of cultural forms other than two-dimensional ones. Thus, chapters are included that trace the history and continuing contribution of traditional media; art, design, craft, and architecture each receive individual chapters. MacDonald, for example, describes the complex meanings of craft and its relationship to fine art and design from classical times to today, as well as summarizes the characteristics and politics of craft today. Furthermore, the influence of technology is charted principally through conventional art, and the chapters on photography, film, and fashion are likewise cast largely in terms of historical accounts of whether these forms should be considered to be art.The historical bias is equally evident in the pictures used to illustrate the text. While, for example, there are contemporary popular images, such [End Page 118] as a cover of the Sun newspaper and a photograph of Punks, there are as many crossover images—postcards of famous art portraits and a Michelangelo on a T shirt—as well as many conventional artworks. Delacroix, Corbert, Rauschenberg, David, Fuseli, and Van Goyen are each featured. Some of the popular images are also historical, such as George Mêlées 1902 classic film Voyage to Moon and advertisements from the1930s.Sometimes the historical material takes up much of the space, with recent developments given only cursory treatment, and sometimes the material is dealt with in ways that seem rather old-fashioned to this reader. For example, Glyn Davis's chapter on photography and film is primarily a potted historical account of the relationships between these two cultural forms and art. Further, Davis does not just describe the arguments for and against their inclusion as art but is clearly engaged with these issues himself, an engagement that many proponents of visual culture would find rather quaint—that is, rather less interesting than the particular contribution that these forms make to contemporary life and for whom the question, "Is it art?" is no longer of any particular interest. This art orientation also colors Davis's view of Hollywood films. Clearly preferring "art" films, he completely ignores the role of popular film in exploring the fears, anxieties, beliefs, and so on of the wider public. By contrast, Richard Williams argues against architecture as a form of art, with its limited concerns with aesthetics, style, and canonical buildings, in favor of architecture as discourse and spatial experience. He is more interested in the reception of architecture than its production—first with architecture as signs, as meanings that are mutable, contingent, and arbitrary; and, secondly, as ordinary urban lived experience, with how architecture is but one element within the experience of urban environments.Typical of the avoidance of technical terms in the book as a whole, Williams beautifully describes the difference between structuralism and poststructuralism without once mentioning either of these terms, and in a chapter on architecture he manages to use the term "postmodern" only once. Similarly, in Neil Mulholland's chapter on representation and realism, cultural border crossing and indigenization are both described, albeit briefly, though without recourse to these terms... (shrink)

The first part of this paper surveys the visual technologies that have transformed the modern visual environment and argues for the relevance of their study to an understanding of modernity in general and to the field of religion and science in particular. The term cosmography is adopted for the visual and spatial manifestation of a worldview, and the importance of analyzing and advancing modern cosmography is asserted. In the second part, the focus shifts to one particular (...) challenge presented by modern cosmography: how to represent and find visual meaning in the new range of size scales that have been offered up by the modern scientific worldview. Six strategies for representing and finding meaning in this new expanded picture of the universe are explored. (shrink)

The emulation theory of representation is developed and explored as a framework that can revealingly synthesize a wide variety of representational functions of the brain. The framework is based on constructs from control theory (forward models) and signal processing (Kalman filters). The idea is that in addition to simply engaging with the body and environment, the brain constructs neural circuits that act as models of the body and environment. During overt sensorimotor engagement, these models are driven by efference copies in (...) parallel with the body and environment, in order to provide expectations of the sensory feedback, and to enhance and process sensory information. These models can also be run off-line in order to produce imagery, estimate outcomes of different actions, and evaluate and develop motor plans. The framework is initially developed within the context of motor control, where it has been shown that inner models running in parallel with the body can reduce the effects of feedback delay problems. The same mechanisms can account for motor imagery as the off-line driving of the emulator via efference copies. The framework is extended to account for visual imagery as the off-line driving of an emulator of the motor-visual loop. I also show how such systems can provide for amodal spatial imagery. Perception, including visual perception, results from such models being used to form expectations of, and to interpret, sensory input. I close by briefly outlining other cognitive functions that might also be synthesized within this framework, including reasoning, theory of mind phenomena, and language. Key Words: efference copies; emulation theory of representation; forward models; Kalman filters; motor control; motor imagery; perception; visual imagery. (shrink)

The posterior parietal cortex (PPC) is the most likely site where egocentric spatial relationships are represented in the brain. PPC cells receive visual, auditory, somaesthetic, and vestibular sensory inputs; oculomotor, head, limb, and body motor signals; and strong motivational projections from the limbic system. Their discharge increases not only when an animal moves towards a sensory target, but also when it directs its attention to it. PPC lesions have the opposite effect: sensory inattention and neglect. The PPC does (...) not seem to contain a “map” of the location of objects in space but a distributed neural network for transforming one set of sensory vectors into other sensory reference frames or into various motor coordinate systems. Which set of transformation rules is used probably depends on attention, which selectively enhances the synapses needed for making a particular sensory comparison or aiming a particular movement. (shrink)

Using a novel enumeration task, we examined the encoding of spatial information during subitizing. Observers were shown masked presentations of randomly-placed discs on a screen and were required to mark the perceived locations of these discs on a subsequent blank screen. This provided a measure of recall for object locations and an indirect measure of display numerosity. Observers were tested on three stimulus durations and eight numerosities. Enumeration performance was high for displays containing up to six discs—a higher subitizing (...) range than reported in previous studies. Error in the location data was measured as the distance between corresponding stimulus and response discs. Overall, location errors increased in magnitude with larger numerosities and shorter display durations. When errors were computed as disc distance from display centroid, results suggest a compressed representation by observers. Additionally, enumeration and localization accuracy increased with display regularity. (shrink)

Ross argues that the location problem for color-the problem of how it is represented as occupying a particular location in space-constitutes an objection to color subjectivism. There are two ways in which the location problem can be interpreted. First, it can be read as a why-question about the relation of visual experience to the environment represented: Why does visual experience represent a patch of color as located in this part of space rather than that? On this interpretation, the (...) subjectivist can answer Ross's objection by appealing to the physical location of reflectance rather than color. Second, it can be read as a how-question about visual representation itself: How does visual experience put together the experience of a color with the experience of its being located in space? This version makes the location problem a problem about visual experience itself and renders the ontology of color irrelevant to its solution. The location problem is thus no more a problem for the color subjectivist than for the color realist. (shrink)

To learn a visual code in an unsupervised manner, one may attempt to capture those features of the stimulus set that would contribute significantly to a statistically efficient representation. Paradoxically, all the candidate features in this approach need to be known before statistics over them can be computed. This paradox may be circumvented by confining the repertoire of candidate features to actual scene fragments, which resemble the “what+where” receptive fields found in the ventral visual stream in primates. We (...) describe a single-layer network that learns such fragments from unsegmented raw images of structured objects. The learning method combines fast imprinting in the feedforward stream with lateral interactions to achieve single-epoch unsupervised acquisition of spatially localized features that can support systematic treatment of structured objects [1]. (shrink)

These essays by Robert Schwartz on topics in the theory of vision are written from a pragmatic perspective. The issues and arguments will interest both philosophers and psychologists, covering new ground and bridging gaps between these disciplines. Schwartz begins historically, with discussions of problems raised and solutions offered in Bishop Berkeley's writings on vision, presenting Berkeley's views on spatial perception and the qualitative aspects of sensory experience in the context of recent theoretical and empirical work in vision theory. Schwartz (...) then turns to debates in both the philosophical and psychological literature over the view that perception is inferential and thus "indirect." Critically surveying competing characterizations of the idea of "inferential processes" he argues the need either to reframe radically the question or drop the issue. Next, Schwartz discusses pictorial representation and research on picture perception. Drawing on the work of Nelson Goodman, Schwartz explains and defends the advantages of a symbolic approach to both topics. Finally, he examines the quagmires that often develop when metaphysical concerns about the "real" and our ability to perceive it infect discussions and claims in the theory of vision. After analyzing issues arising in current psychological research on "object" perception, Schwartz turns to debates over the supposed essential nature of colors. An appreciation of the empirical and theoretical work on color perception suggests that there is no single or privileged analysis of the notion of "real colors." Schwartz circles back in the end to what he calls "that old chestnut of the philosophy of perception"--controversies over "the objects of perception"--and takes an Austinian look at the topic. (shrink)

This paper describes an operational computer simulation of visual mental imagery in humans. The structure of the simulation was motivated by results of experiments on how people represent information in, and access information from, visual images. The simulation includes a “surface representation,” which is spatial and quasi‐pictorial, and an underlying “deep representation,” which contains “perceptual” information encoding appearance plus “propositional” information describing facts about an object. The simulation embodies a theory of how surface images are generated from (...) deep representations, and how surface images are processed when one accesses information embedded in them. The simulation also offers an account of various sorts of imagery transformations. (shrink)

This somewhat odd paper argues against a representational view of visual experience using an intricate "inversion" type thought experiment involving double vision: two subjects could represent external space in the same way while differing phenomenally due to different "spread" in their double images. The spatial structure of the visual field is explained not by representation of external space but functionally, in terms of the possible locations of an attentional spotlight. -/- I'm fond of the ideas in this (...) paper but doubt I'll be returning to it soon. (shrink)

May implicit and explicit collaboration influence text comprehension and spatial recognition interaction? Visuospatial representation implies implicit, visual and spatial processing of actions and concepts at different levels of awareness. Implicit learning is linked to unaware, nonverbal and prototypical processing, especially in the early stages of development when it is prevailing. Spatial processing is studied as knowledge prototypes , conceptual and mind maps . According to the hypothesis that text comprehension and spatial recognition connecting processes may (...) also be implicit, this paper analyzes the possibility to identify and to define implicit non verbal criteria for organizing concepts into spatial representation. The focus of the research question is if prototypical processing (mainly implicit, but also explicit) criteria of conceptual organization may be model based. According to Thinking Prototypes Theory , explicit knowledge could be supported by implicit models of basic processing. On implicit side, conceptual development could be the resultant of the increasing complexity of prototypical implicit models interaction during individual lifespan, as in conceptual change research explicit conceptual development may be dependent on correlation . Unlike Theory Theory in Thinking Prototypes Theory implicit processing may collaborate with explicit knowledge without transforming itself from implicit to explicit. Prototypical implicit processing is considered as an entanglement of basic functions operating synergically in a complex way. Prototypical implicit processing units may be classified as far as they concern different basic thinking operations ( add , chain , each , compare , focus and link ). The experimental design was developed with primary school students in Naples. (shrink)

Empirical discussions of mental representation appeal to a wide variety of representational kinds. Some of these kinds, such as the sentential representations underlying language use and the pictorial representations of visual imagery, are thoroughly familiar to philosophers. Others have received almost no philosophical attention at all. Included in this latter category are analogue magnitude representations, which enable a wide range of organisms to primitively represent spatial, temporal, numerical, and related magnitudes. This article aims to introduce (...) analogue magnitude representations to a philosophical audience by rehearsing empirical evidence for their existence and analysing their format, their content, and the computations they support. 1 Background1.1 Evidence of analogue magnitude representations1.2 Weber’s law1.3 Scepticism about analogue magnitude representations2 Format2.1 Carey’s analogy2.2 Neural realization2.3 Analogue representation2.4 Analogue magnitude representation components3 Content3.1 Do analogue magnitude representations have representational content?3.2 What do analogue magnitude representations represent?3.3 What content types do analogue magnitude representations have?4 Computations4.1 Arithmetic computation4.2 Practical deliberation5 Conclusion. (shrink)

Eye movements during mental imagery are not epiphenomenal but assist the process of image generation. Commands to the eyes for each fixation are stored along with the visual representation and are used as spatial index in a motor‐based coordinate system for the proper arrangement of parts of an image. In two experiments, subjects viewed an irregular checkerboard or color pictures of fish and were subsequently asked to form mental images of these stimuli while keeping their eyes open. During (...) the perceptual phase, a group of subjects was requested to maintain fixation onto the screen's center, whereas another group was free to inspect the stimuli. During the imagery phase, all of these subjects were free to move their eyes. A third group of subjects (in Experiment 2) was free to explore the pattern but was requested to maintain central fixation during imagery. For subjects free to explore the pattern, the percentage of time spent fixating a specific location during perception was highly correlated with the time spent on the same (empty) locations during imagery. The order of scanning of these locations during imagery was correlated to the original order during perception. The strength of relatedness of these scanpaths and the vividness of each image predicted performance accuracy. Subjects who fixed their gaze centrally during perception did the same spontaneously during imagery. Subjects free to explore during perception, but maintaining central fixation during imagery, showed decreased ability to recall the pattern. We conclude that the eye scanpaths during visual imagery reenact those of perception of the same visual scene and that they play a functional role. (shrink)

Theories of the representation of specific kinetic and spatiotem-poral features of movement range from the explicit assertion that temporal aspects of movement are not represented to the idea that they are represented and that they have neurophysiological correlates. Jeannerod's thesis is that mental and visual images have common mechanisms and that there is a link between the image to move and the mechanisms involved with movement. The target article takes the position that certain parameters are coded in motor (...) class='Hi'>representations but that the duration of an action is not one of them. This position is based on the work of Gottlieb et al. and of Decety et al.. Both these studies are worth considering in detail. In Note 1, Jeannerod suggests that: “in time-constrained tasks subjects control the amplitude parameter of force impulses, whereas in spatially constrained tasks the duration of the force impulse is affected by accuracy demands.” This is not exactly correct. Excitation pulse intensity is modulated both in tasks that require spatial and those that require temporal accuracy. Excitation pulse duration is modulated for changes in movement distance and inertial load. If subjects are required to be very accurate spatially, they will move at less than maximum speed for a given distance and this is achieved by lower levels of excitation intensity. (shrink)