This article discusses how research on the image-based analysis of facial images has informed this debate by demonstrating that a single representational system for facial identity and facial expression is not only computationally viable, but can simulate existing cognitive data demonstrating apparent dissociable processing of these two facial properties. It discusses the increasing number of cognitive studies that provide support for this view. Neuropsychological case studies of brain-injured patients and provide limited evidence for separate visual routes processing (...) facial identity and facial expression. It deals with neuroimaging studies addressing both facial identity and facial expression processing which shows that the fusiform gyrus contributes to the recognition of both facial properties. Research continues to reinforce the proposal that a common visual framework supports the representation of at least some aspects of facial identity and facial expression. (shrink)

Oyeyemi's critique of racism in the United States focuses on the visual binary between whiteness and blackness, which she shows working in multiple ways to warp and distort relationships. In the Whitman family, children are valued (or not valued) according to how their skin color registers on a scale determined by white superiority. Oyeyemi's approach to racism takes the circuitous route of retelling the fairy tale of “Little Snow White,” thus calling into her own narrative a foundational text of (...) Western cultural aesthetics which links beauty to whiteness. (Snow White, whose skin is “white as snow,” is “fairest in the land.”) Rather than narrate a new version of the fairy tale, Oyeyemi separates out its elements – magic mirror, evil stepmother, and beautiful white stepdaughter – and develops each into a new thematic configuration. My analysis focuses on the subtle ways that Oyeyemi's reshaping of mirror, evil stepmother, and innocent beautiful young girl exposes the harms to children inflicted by allegiance to a (false) structure of visible difference between white skin and black skin. (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)

Norman presents intriguing arguments in support of a mapping between ecological and constructivist visual cognition, on the one hand, onto the dorsal ventral dual route processing hypothesis, on the other hand. Unfortunately, his account is incompatible with developmental data on the functional emergence of the dorsal and ventral routes. We argue that it is essential for theories of adult visual cognition to take constraints from development seriously.

A visual analogue, two-route model of somatosensory processing is advanced in this commentary. Touch for perception is seen as separate from, although interconnected with, touch for action. Separate modules are additionally proposed for internal (body) and external (object-related) somatosensation. Here we ask whether dissociation (divide) guarantees better efficiency (impera) in terms of the heuristic model within the somatosensory modality and across modalities.

Drawing on video-recorded data from pre-climbing route mapping with visually impaired climbers and a sight guide, this study uses conversation analysis to investigate the situated deployment of the Italian presentative (e) hai ‘(and) you have’ within locally routinized multimodal Gestalts. The study shows that the guide uses (e) hai to progress route mapping and engage the athlete in tactile actions that target specific features of the route. In this context, (e) hai is packaged with noun phrases, silent pauses, bodily movements, (...) and touch. The arrangement of such syntactic and embodied components is shown to follow a recurrent trajectory in which, between (e) hai and its grammatical completion, syntactic suspension creates a dedicated slot for guide and athlete to physically attain the target object. Routine embeddedness of (e) hai within such arrangement is shown to provide specific affordances to the athletes to anticipate subsequent action and engage in its embodied implementation. (shrink)

Social advertising often employs persuasive imagery in support of a morally laden cause. These visual arguments can take the form of veridical representations of the given situation or the form of purposeful visual blends. Both visual routes to persuasion have serious ethical issues to confront. In what concerns the purportedly veridical images, controversies about picture retouching and framing have cast many doubts on their success in offering unmediated access to a given reality. Editorial interests have proven (...) far too influential on the destiny of what and how is presented to the audience from the amount of visual material available on a topic. Even when the audience is certain that photos are not doctored, the use of veridical images may be seen as unethical. Their disproportionate affective impact may lead the audience to hold biased opinions, since other concerns may be impossible to capture in a vivid picture. Visual blends may be the answer to this problem, employing the fictional or the figurative to help the viewer grasp the moral anatomy of a given situation. Their generous use of figurative meaning may be seen as their strength and their weakness at the same time. It makes them less likely to face accusations of distorting reality, because they do not claim to be windows on reality per se. At the same time, it makes them vulnerable to interpretations that miss their true point – one might appreciate the artistry of a visual metaphor or a visual pun and fail to consider the statement it makes about a given situation. Contemporary philosophical approaches to the place of visuals in moral persuasion inform my analysis of the use of visual arguments in charity-oriented advertising. (shrink)

First published in 1995, The Visual Brain in Action remains a seminal publication in the cognitive sciences. It presents a model for understanding the visual processing underlying perception and action, proposing a broad distinction within the brain between two kinds of vision: conscious perception and unconscious 'online' vision. It argues that each kind of vision can occur quasi-independently of the other, and is separately handled by a quite different processing system. In the 11 years since publication, the book (...) has provoked considerable interest and debate - throughout both cognitive neuroscience and philosophy, while the field has continued to flourish and develop. -/- For this new edition, the text from the original edition has been left untouched, standing as a coherent statement of the authors' position. However, a very substantial epilogue has been added to the book in which Milner and Goodale review some of the key developments that support or challenge the views that were put forward in the first edition. The new chapter summarizes developments in various relevant areas of psychology, neuroscience and behaviour. It notably supplements the main text by updating the reader on the contributions that have emerged from the use of functional neuroimaging, which was in its infancy when the first edition was written. Neuroimaging, and functional MRI in particular, has revolutionized the field over the past 11 years by allowing investigators to plot in detail the patterns of activity within the visual brains of behaving and perceiving humans. The authors show how its use now allows scientists to test and confirm their proposals, based as they then were largely on evidence accrued from primate neuroscience in conjunction with studies of neurological patients. (shrink)

Man is endowed with brain and mind for comprehending reality of the world. Brain is material entity and is observable, while mind is a non-physical conceived entity. Scientific investigations enhance our knowledge of the functioning of brain and its constituents. They indicate mind-brain association but do not rule out the possibility, in which mind is a property of brain. The perceived reality of the world has both objective and subjective components. The objective components are attributed to brain either alone or (...) in association with mind. The subjective components are considered to be the creations of mind but they appear to contain grains of reality. Attempts made to separate these grains have succeeded partially. One hopes for complete success only after the incorporation of a few missing ingredients. It is our contention that the missing ingredients are human being as an entangled quantum entity - photon field, quantum entity's capability to read information from photon fields of other humans and from its own field reflected by the environment. The evidence for the first ingredient is provided by the analysis of spontaneously emitted visible range photon signals by human beings. The other two ingredients put usual charge- photon interaction in proper context. The experimental results relevant to mind- brain interface are briefly described. A few minutes' time series of small portion of these signals determines their nine properties, which establish quantum nature of signal, and specify quantum state of the dominant component to be squeezed state. Six properties differ in signals emitted at 12 anatomical sites of the same person. Profile of a property for a person is the set of its values at 12 sites. Profile is very informative and can discriminate persons with differing holistic features. Cluster analysis offers procedures for measuring qualitative holistic features e.g. procedure for measuring ‘meditativeness' of a person. The incorporation of other two ingredients chalks out a route for answering the question who we are? (shrink)

The guide dog robot (GDR) is a low-speed companion robot that serves visually impaired people and is used to guide blind people to walk steadily, carrying a variety of intelligent technologies and needing to have the ability to guide with optimal energy consumption in specific scenarios. This paper proposes an innovative technique for virtual-real collaborative path planning and navigation of the GDR specific indoor scenarios, and designs an experimental method for virtual-real collaborative path planning of the GDR specific scenarios. The (...) energy consumption integral equation is used to solve for the energy consumption of the GDR with virtual-real synergy, and the difference in energy consumption is compared for three different navigation directions: horizontal, vertical and oblique obstacle avoidance. The results show that the optimized GDR saves 6.91% in rectilinear movement and 10.60% in curved movement. The efficiency of planning and navigating the GDR in specific domestic scenarios is verified by a virtual-real cooperative. The realization of optimal path planning for energy consumption is instrumental in exploring many of the most significant thought in the path planning and navigation of mobile robots in indoor specific scenarios. (shrink)

The aim of this study was to separately analyze the role of featural and configural face representations. Stimuli containing only featural information were created by cutting the faces into their parts and scrambling them. Stimuli only containing configural information were created by blurring the faces. Employing an old‐new recognition task, the aim of Experiments 1 and 2 was to investigate whether unfamiliar faces (Exp. 1) or familiar faces (Exp. 2) can be recognized if only featural or configural information is provided. (...) Both scrambled and blurred faces could be recognized above chance level. A further aim of Experiments 1 and 2 was to investigate whether our method of creating configural and featural stimuli is valid. Pre‐activation of one form of representation did not facilitate recognition of the other, neither for unfamiliar faces (Exp. 1) nor for familiar faces (Exp. 2). This indicates a high internal validity of our method for creating configural and featural face stimuli. Experiment 3 examined whether features placed in their correct categorical relational position but with distorted metrical distances facilitated recognition of unfamiliar faces. These faces were recognized no better than the scrambled faces in Experiment 1, providing further evidence that facial features are stored independently of configural information. From these results we conclude that both featural and configural information are important to recognize a face and argue for a dual‐mode hypothesis of face processing. Using the psychophysical results as motivation, we propose a computational framework that implements featural and configural processing routes using an appearance‐based representation based on local features and their spatial relations. In three computational experiments (Experiments 4–6) using the same sets of stimuli, we show how this framework is able to model the psychophysical data. (shrink)

The ability to imagine objects undergoing rotation (mental rotation) improves markedly with practice, but an explanation of this plasticity remains controversial. Some researchers propose that practice speeds up the rate of a general-purpose rotation algorithm. Others maintain that performance improvements arise through the adoption of a new cognitive strategy—repeated exposure leads to rapid retrieval from memory of the required response to familiar mental rotation stimuli. In two experiments we provide support for an integrated explanation of practice effects in mental rotation (...) by combining behavioral and EEG measures in a way that provides more rigorous inference than is available from either measure alone. Before practice, participants displayed two well-established signatures of mental rotation: Both response time and EEG negativity increased linearly with rotation angle. After extensive practice with a small set of stimuli, both signatures of mental rotation had all but disappeared. In contrast, after the same amount of practice with a much larger set both signatures remained, even though performance improved markedly. Taken together, these results constitute a reversed association, which cannot arise from variation in a single cause, and so they provide compelling evidence for the existence of two routes to expertise in mental rotation. We also found novel evidence that practice with the large but not the small stimulus set increased the magnitude of an early visual evoked potential, suggesting increased rotation speed is enabled by improved efficiency in extracting three-dimensional information from two-dimensional stimuli. (shrink)

Previous studies have identified the critical role of the left fusiform cortex in visual word form processing, learning, and memory. However, this so-called visual word form area's other functions are not clear. In this study, we used fMRI and the subsequent memory paradigm to examine whether the putative VWFA was involved in the processing and successful memory encoding of faces as well as words. Twenty-two native Chinese speakers were recruited to memorize the visual forms of faces and (...) Chinese words. Episodic memory for the studied material was tested 3. h after the scan with a recognition test. The fusiform face area and the VWFA were functionally defined using separate localizer tasks. We found that, both within and across subjects, stronger activity in the VWFA was associated with better recognition memory of both words and faces. Furthermore, activation in the VWFA did not differ significantly during the encoding of faces and words. Our results revealed the important role of the so-called VWFA in face processing and memory and supported the view that the left mid-fusiform cortex plays a general role in the successful processing and memory of different types of visual objects. © 2010 Elsevier Inc. (shrink)

Neuroscience studies show many examples of very early modulation of visual cortex responses. It is argued that such early routing is essential for a rapid processing of information by the visual system.

In a study concerning visual body part recognition, a “self-advantage” effect, whereby self-related body stimuli are processed faster and more accurately than other-related body stimuli, was revealed, and the emergence of this effect is assumed to be tightly linked to implicit motor simulation, which is activated when performing a hand laterality judgment task in which hand ownership is not explicitly required. Here, we ran two visual hand recognition tasks, namely, a hand laterality judgment task and a self-other discrimination (...) task, to investigate whether the self-advantage emerged even if implicit motor imagery was assumed to be working less efficiently and how individual traits [such as autistic traits and the extent of positive self-body image, as assessed via the Autism Spectrum Quotient and the Body Appreciation Scale-2, respectively] modulate performance in these hand recognition tasks. Participants were presented with hand images in two orientations [i.e., upright and upside-down ] and asked to judge whether it was a left or right hand. They were also asked to determine whether it was their own, or another person’s hand. Data collected from men and women were analyzed separately. The self-advantage effect in the hand laterality judgment task was not revealed, suggesting that only two orientation conditions are not enough to trigger this motor simulation. Furthermore, the men’s group showed a significant positive correlation between AQ scores and reaction times in the laterality judgment task, while the women’s group showed a significant negative correlation between AQ scores and differences in RTs and a significant positive correlation between BAS-2 scores and dprime in the self-other discrimination task. These results suggest that men and women differentially adopt specific strategies and/or execution processes for implicit and explicit hand recognition tasks. (shrink)

This article proposes the concept of blind visuality as a response to the injunction to look differently at both visual images, and vision itself, posed by Bruce Horak’s exhibition Through a Tired Eye. The brightly colored impressionistic paintings suggest an artist who revels in the domain of the visual, yet he describes his practice as a representation of blindness. This accessible exposition of blind visuality speaks to the broad question of what critical disability arts contribute to discourses about (...) vision, visuality and spectatorship in the arts. I analyze Horak’s paintings as examples of blind epistemology and haptic visuality, showing that this work evokes a way of seeing that blurs the boundaries between vision and embodied feeling. I argue that by expanding understandings of vision and multi-sensory knowledge, deconstructing the separation between vision and haptic perception, and challenging western ocularcentricism, blind visuality poses an alternative economy of looking that reflects disability aesthetics, shifts from individualism to relationality, and challenges understandings of perception/knowledge as a form of mastery. (shrink)

The aim of this study was to find out how people process the dialectal variation encountered in the daily linguistic input. We conducted an eye tracking study (Visual Word Paradigm) that targeted the predictive processing of grammatical gender markers. Three different groups of Norwegian speakers took part in the experiment: one group of students from the capital Oslo, and two groups of dialect speakers from the Western Norwegian town Sogndal. One Sogndal group was defined as ``stable dialect speakers'', and (...) one as ``unstable dialect speakers'', based on a background questionnaire. The students participated in two eye tracking experiments each, one conducted in the their own dialect, and one in the other dialect (i.e., Sogn dialect for the Oslo students, and Oslo dialect for the Sogndal students). The gender systems in the two dialects differ: the Sogn dialect makes an obligatory three-gender split (Masculine, Feminine and Neuter) whereas the Oslo dialect only obligatorily makes a two gender distinction. The research question was whether speakers could use gender markers to predict the upcoming target noun in both local and non-local dialect mode, and furthermore, if they correctly could adjust their expectations based on dialect mode. The results showed that the Sogn speakers could predict upcoming linguistic material both in the local and Oslo dialect, but only the stable group were able to adjust their predictions based on the dialect mode. The unstable group applied a more general Oslo-compatible parsing to both the local and the non-local dialect. The Oslo speakers on the other hand were able to use gender markers as predictors only in their own dialect. We argue that the stable Sogn group should be treated as a bilingual group, as they show native-like skills in both varieties, while the unstable Sogn group can be seen as accommodated monolinguals, in that they treat the two varieties as sharing an underspecified grammar. The Oslo group on the other hand lacks sufficient competence in the other dialect to make use of grammatical markers to make predictions. (shrink)

& Visual object representation was studied in free-ranging rhesus monkeys. To facilitate comparison with humans, and to provide a new tool for neurophysiologists, we used a looking time procedure originally developed for studies of human infants. Monkeys’ looking times were measured to displays with one or two distinct objects, separated or together, stationary or moving. Results indicate that rhesus monkeys..

Can visual thinking be a means of discovery in elementary analysis, as well as a means of illustration and a stimulus to discovery? The answer to the corresponding question for geometry and arithmetic seems to be ‘yes’ (Giaquinto [1992], [1993]), and so a positive answer might be expected for elementary analysis too. But I argue here that only in a severely restricted range of cases can visual thinking be a means of discovery in analysis. Examination of persuasive (...) class='Hi'>visual routes to two simple theorems (Rolle, Bolzano) shows that they are not ways of discovering the theorems; the type of visual thinking involved can never be used to discover analytic theorems of a certain generality. The hypothesis that visual thinking is never a means of discovering the existence or nature of the limit of some infinite process is considered, and a likely counter-example is set out. It is still possible that restricted theorems can be discovered visually: an example from Littlewood is examined in detail and not found wanting. Even when visual thinking is not a means of discovery it can provide the idea for a proof in a direct way; an example is presented (Intermediate Value Theorem). In conclusion: it may be possible to discover theorems in elementary real analysis by visual means, but only theorems of a restricted kind; however, visual thinking in analysis can be very useful in other ways. (shrink)

Capacities for abstract thinking and problem‐solving are central to human cognition. Processes of abstraction allow the transfer of experiences and knowledge between contexts helping us make informed decisions in new or changing contexts. While we are often inclined to relate such reasoning capacities to individual minds and brains, they may in fact be contingent on human‐specific modes of collaboration, dialogue, and shared attention. In an experimental study, we test the hypothesis that social interaction enhances cognitive processes of rule‐induction, which in (...) turn improves problem‐solving performance. Through three sessions of increasing complexity, individuals and groups were presented with a problem‐solving task requiring them to categorize a set of visual stimuli. To assess the character of participants’ problem representations, after each training session, they were presented with a transfer task involving stimuli that differed in appearance, but shared relations among features with the training set. Besides, we compared participants’ categorization behaviors to simulated agents relying on exemplar learning. We found that groups performed superior to individuals and agents in the training sessions and were more likely to correctly generalize their observations in the transfer phase, especially in the high complexity session, suggesting that groups more effectively induced underlying categorization rules from the stimuli than individuals and agents. Crucially, variation in performance among groups was predicted by semantic diversity in members’ dialogical contributions, suggesting a link between social interaction, cognitive diversity, and abstraction. (shrink)

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

The article considers how the use of duplicates and the practice of photography interacted in museums of ethnography, contributing to the ambivalent framing of ethnographic objects as items that can be both scientific specimens and works of art. It focuses on the Musée d'ethnographie du Trocadéro in Paris and on the key period of its reorganization between 1928 and 1935, which was central to the institutionalization of French ethnology. By examining the place of duplicates in this museum, as well as (...) the major role attributed to photographs of objects and their materiality, the paper shows that these others of the ethnographic artefacts, often considered separately from their originals, still participated in the same project: the development of the museum and its growing cultural influence. While the duplicates positioned the museum in the various networks of the scientific community, the photographs appealed to the avant-garde, amateurs, African and Oceanian art dealers and the general public. (shrink)

Andrew Torrance has recently argued that we can distinguish analytic theology from analytic philosophy of religion if we understand theology as, fundamentally, a scientific enterprise. However, this distinction holds only if philosophy of religion is not itself a science in the sense intended by Torrance. I argue that philosophy of religion is a science in this sense, and so, that Torrance cannot distinguish theology from philosophy of religion in the way suggested. Nevertheless, I offer two alternative routes to the (...) distinction based on the nature of the respective objects of study in theology and philosophy of religion. Thus, I demonstrate that there is a coherent model available to Torrance which preserves the distinction he seeks. (shrink)

Among the extant masterworks of Roman art, there is probably none that has generated more scholarly debate than the Portland Vase over the interpretation of its elegant frieze. No fewer than forty-four different theories attempting to interpret the scenes on the vase have appeared in the last 400 years. In the main, the theories fall into two categories, those relating the frieze to Greek myth, and those linking the figures to Roman personages. Moreover, there is no consensus whether the frieze (...) is two separate scenes or one continuous story. The obstacle to interpreting the frieze is that all but one of the figures lack identifying attributes. This paper will demonstrate (1) that in lieu of standard iconography, a synthesis of visual and literary tropes in the form of hidden letters, that is, cryptograms, tells the viewer how to read the frieze; (2) that scene A of the frieze illustrates specifically lines 26-30 of Catullus 64 by visually rendering the epithets and tropes used in those lines; (3) that visual reproductions of other tropes in Catullus 64 further substantiate the relationship between frieze and poem; (4) that scene B of the frieze is an intentional aberration from the poem; (5) that there is a complex and unfinished interaction between scenes A and B which the viewer must complete; and (6) that in the final analysis, the frieze duplicates both the theme and central structure of Catullus 64.10 . (shrink)

An important debate in the reasoning literature concerns the extent to which inference processes are domain-free or domain-specific. Typically, evidence in support of the domain-specific position comprises the facilitation observed when abstract reasoning tasks are set in realistic context. Three experiments are reported here in which the sources of facilitation were investigated for contextualised versions of Raven's Progressive Matrices (Richardson, 1991) and non-verbal analogies from the AH4 test (Richardson & Webster, 1996). Experiment 1 confirmed that the facilitation observed for the (...) contextualised matrices was in part due to extraneous aspects of commentaries originally intended to activate domainspecific processes. Experiments 2 and 3 indicated that the remainder of the facilitation for the matrices, and all of the facilitation for the analogies, could be explained by visual salience: Converting the item elements into realistic objects had enabled them and their transitions to be identified more easily. Hence, performance at simplified abstract items was as good as, or better than, at contextualised items. It is concluded that facilitation effects cannot be interpreted as showing that domain-specific processes constitute a self-contained system separate from domain-free processes. In turn, this means that domain-free processes cannot be dismissed as being unimportant for reasoning. (shrink)

& Awareness of change within a visual scene only occurs in subjects were aware of, replicated those attentional effects, but the presence of focused attention. When two versions of a.

Neuroscientists are able to detect physical changes in information entropy in the available neurodata. However, the information paradigm is inadequate to describe fully nervous dynamics and mental activities such as perception. This paper suggests explanations to neural dynamics that provide an alternative to thermodynamic and information accounts. We recall the Banach–Tarski paradox, which informally states that when pieces of a ball are moved and rotated without changing their shape, a synergy between two balls of the same volume is achieved instead (...) of the original one. We show how and why BTP might display this physical and biological synergy meaningfully, making it possible to model nervous activities. The anatomical and functional structure of the central nervous system’s nodes and edges makes it possible to perform a sequence of moves inside the connectome that doubles the amount of available cortical oscillations. In particular, a BTP-based mechanism permits scale-invariant nervous oscillations to amplify and propagate towards widely separated brain areas. Paraphrasing the BTP’s definition, we could state that: when a few components of a self-similar nervous oscillation are moved and rotated throughout the cortical connectome, two self-similar oscillations are achieved instead of the original one. Furthermore, based on topological structures, we illustrate how, counterintuitively, the amplification of scale-free oscillations does not require information transfer. (shrink)

This study investigates switching costs in landmark-based wayfinding using olfactory and visual landmark information. It has already been demonstrated that there seem to be no switching costs, in terms of correct route decisions, when switching between acoustically and visually presented landmarks. Olfaction, on the other hand, is not extensively focused on in landmark-based wayfinding thus far, especially with respect to modality switching. The goal of this work is to empirically test and compare visual and olfactory landmark information with (...) regard to their suitability for wayfinding including a modality switch. To investigate this, an experiment within a virtual environment was conducted in which participants were walked along a virtual route of 12 intersections. At each intersection, landmark information together with directional information was presented, which was to be memorized and recalled in the following phase, either in the same or in the other modality. The results of the study show that, in contrast to the no-switching costs between auditory and visual landmarks in previous studies, switching costs occur when switching modality from visual to olfactory and vice versa. This is indicated by both longer decision times and fewer correct decisions. This means that a modality switch involving olfactory landmark information is possible but could lead to poorer performance. Therefore, olfaction may still be valuable for landmark-based-wayfinding. We argue that the poorer performance in the switching-condition is possibly due to higher cognitive load and the separate initial processing of odors and images in different cognitive systems. (shrink)

One often hears it said that our visual-perceptual contact with the world is “perspectival.” But this can mean quite different things. Three different senses in which our visual contact with the world is “perspectival” are distinguished. The first involves the detection or representation of behaviorally important relations, holding between a perceiving subject and the world. These include time to contact, body-scaled size, egocentric position, and direction of heading. The second perspective becomes at least explicitly manifest in taking up (...) the “proximal mode” and involves the representation of relational “appearance properties,” such as, perhaps , angular size and angular/projective shape at or from a viewpoint. The third perspective is associated with the pencil of rays structured by the position and geometry of the eyes. The relationships between these three perspectives are charted, and their connection with conscious experiential awareness discussed. So, e.g., there is no simple or direct route from the detection of the relations constitutive of perspective2 to detection of the relations constitutive of perspective1. The relations definitive of perspective3 are probably not themselves detected or represented by the visual system, but define the informational arena within which detection of the relations definitive of perspective1 and perspective2 takes place. (shrink)