Neuroscientists commonly assume that the brain generates representations of a scene in various non-retinotopic 3D coordinate frames, for example in 'egocentric' and 'allocentric' frames. Although neurons in early visual cortex might be described as representing a scene in an eye-centred frame, using 2 dimensions of visual direction and one of binocular disparity, there is no convincing evidence of similarly organized cortical areas using non-retinotopic 3D coordinate frames nor of any systematic transfer of information from one frame to another. We propose (...) that perception and action in a 3D world could be achieved without generating ego- or allocentric 3D coordinate frames. Instead, we suggest that the fundamental operation the brain carries out is to compare a long state vector with a matrix of weights to choose an output. The processes involved in perception of a 3D scene and action within it depend, we suggest, on successive iterations of this basic operation. Advantages of this proposal include the fact that it relies on computationally well-defined operations corresponding to well-established neural processes. Also, we argue that from a philosophical perspective it is at least as plausible as theories postulating 3D coordinate frames. Finally, we suggest a variety of experiments that would falsify our claim. (shrink)

Very encouraging results have been obtained from a new program that derives a dense three-dimensional evidence grid representation of a robot's surroundings from wide-angle stereoscopic images. The pro gram adds several spatial rays of evidence to a grid for each of about 2,500 local image features chosen per stereo pair. It was used to construct a 256x256x64 grid, representing 6 by 6 by 2 meters, from a hand- collected test set of twenty stereo image pairs of an office scene. Fifty (...) nine stereo pairs of an 8 by 8 meter laboratory were also processed. The positive (probably occupied) cells of the grids, viewed in perspec tive, resemble dollhouse scenes. Details as small as the curvature of chair armrests are discernible. The processing time, on a 100 MIPS Sparc 20, is less than five seconds per stereo pair, and total memory is under 16 megabytes. The results seem abundantly adequate for very reliable navigation of freely roaming mobile robots, and plausibly adequate for shape identification of objects bigger than 10 centimeters. The program is a first proof of concept, and awaits optimizations, enhancements, variations, extensions and applications. (shrink)

Two experiments were performed to explore the mechanisms of human 3D shape perception. In Experiment 1, the subjects’ performance in a shape constancy task in the presence of several cues (edges, binocular disparity, shading and texture) was tested. The results show that edges and binocular disparity, but not shading or texture, are important in 3D shape perception. Experiment 2 tested the effect of several simplicity constraints, such as symmetry and planarity on subjects’ performance in a shape constancy task. The 3D (...) shapes were represented by edges or vertices only. The results show that performance with or without binocular disparity is at chance level, unless the 3D shape is symmetric and/or its faces are planar. In both experiments, there was a correlation between the subjects’ performance with and without binocular disparity. Our study suggests that simplicity constraints, not depth cues, play the primary role in both monocular and binocular 3D shape perception. These results are consistent with our computational model of 3D shape recovery. (shrink)

There has been a surge in mass media reports extolling the potential for using three-dimensional printing of biomaterials to treat a wide range of clinical conditions. Given that mass media is recognized as one of the most important sources of health and medical information for the general public, especially prospective patients, we report and discuss the ethical consequences of coverage of 3D bioprinting in the media. First, we illustrate how positive mass media narratives of a similar biofabricated technology, namely the (...) Macchiarini scaffold tracheas, which was involved in lethal experimental human trials, influenced potential patient perceptions. Second, we report and analyze the positively biased and enthusiastic portrayal of 3D bioprinting in mass media. Third, we examine the lack of regulation and absence of discussion about risks associated with bioprinting technology. Fourth, we explore how media misunderstanding is dangerously misleading the narrative about the technology. (shrink)

The experiments reported herein probe the visual cortical mechanisms that control near–far percepts in response to two-dimensional stimuli. Figural contrast is found to be a principal factor for the emergence of percepts of near versus far in pictorial stimuli, especially when stimulus duration is brief. Pictorial factors such as interposition (Experiment 1) and partial occlusion Experiments 2 and 3) may cooperate, as generally predicted by cue combination models, or compete with contrast factors in the manner predicted by the (...) FACADE model. In particular, if the geometrical conŽ guration of an image favors activation of cortical bipole grouping cells, as at the top of a T-junction, then this advantage can cooperate with the contrast of the conŽ guration to facilitate a near–far percept at a lower contrast than at an X-junction. Varying the exposure duration of the stimuli shows that the more balanced bipole competition in the X-junction case takes longer exposure times to resolve than the bipole competition in the T-junction case (Experiment 3). (shrink)

Humanoid robots are projected to be mass marketed in the future in several fields of application. Today, however, user evaluations of humanoid robots are often based on mediated depictions rather than actual observations or interactions with a robot, which holds true not least for scientific user studies. People can be confronted with robots in various modes of presentation, among them 2D videos, 3D, i.e., stereoscopic videos, immersive Virtual Reality, or live on site. A systematic investigation into how such differential modes (...) of presentation influence user perceptions of a robot is still lacking. Thus, the current study systematically compares the effects of different presentation modes with varying immersive potential on user evaluations of a humanoid service robot. Participants observed an interaction between a humanoid service robot and an actor either on 2D or 3D video, via a virtual reality headset or live. We found support for the expected effect of the presentation mode on perceived immediacy. Effects regarding the degree of human likeness that was attributed to the robot were mixed. The presentation mode had no influence on evaluations in terms of eeriness, likability, and purchase intentions. Implications for empirical research on humanoid robots and practice are discussed. (shrink)

Facial information is a powerful channel for human-to-human communication. Characteristically, faces can be defined as biological objects that are four-dimensional (4D) patterns, whereby they have concurrently a spatial structure as well as temporal dynamics. The spatial characteristics of facial objects possess three dimensions (3D), namely breadth, height and importantly, depth. The temporal properties of facial objects are defined by how a 3D facial structure evolves dynamically over time; where time is referred to as the fourth dimension (4D). Our entire perspective (...) of another’s face, whether it be social, affective or cognitive perceptions, is therefore built on a combination of 3D and 4D visual cues. Counterintuitively, over the past few decades of experimental research in psychology, facial stimuli have largely been presented to participants as a spatial pattern that has been flattened into two dimensions (2D), while remaining largely static. The following review aims to advance and update facial researchers, on the recent revolution in computer-generated, realistic 4D facial models produced from real-life human subjects. We delve in-depth to summarize recent studies which have utilized facial stimuli that possess 3D structural cues (geometry and depth) and 4D temporal cues (3D structure + dynamic viewpoint and movement). In sum, we have found that higher-order perceptions such as identity, gender, ethnicity, emotion and personality, are critically influenced by the 4D characteristics embedded within natural human faces. In future, it is recommended that facial stimuli incorporate the 4D space-time perspective with the proposed time-resolved methods. (shrink)

Despite the increasing number of studies on user experience and user interfaces, few studies have examined emotional interaction between humans and deformable objects. In the current study, we investigated how the anthropomorphic design of a flexible display interacts with emotion. For 101 unique 3D images in which an object was bent at different axes, 281 participants were asked to report how strongly the object evoked five elemental emotions (e.g., happiness, disgust, anger, fear, and sadness) in an online survey. People rated (...) the object’s shape using three emotional categories: happiness, disgust–anger, and sadness–fear. It was also found that a combination of axis of bending (horizontal or diagonal axis) and convexity (bending convexly or concavely) predicted emotional valence, underpinning the anthropomorphic design of flexible displays. Our findings provide empirical evidence that axis of bending and convexity can be an important antecedent of emotional interaction with flexible objects, triggering at least three types of emotion in users. (shrink)

Every linear perspective image has a center of the perspective construction. Only when observed from that location does a 2D image provide the same stimulus as the original 3D scene. Geometric analyses indicate that observing the image from other vantage points should affect the perceived spatial structure of the scene conveyed by the image, involving transformations such as shear, compression, and dilation. Based on previous research, this paper presents a detailed account of these transformations. The analyses are presented in a (...) uniform manner, illustrated with special 3D diagrams, and embedded in a wider framework of related perspective paradigms. Such analyses provide the potential theoretical basis for empirical work on the effects of changes of observer vantage points on the perception of spatial structure in perspective images. (shrink)

It is common for visitors to have rich and varied experiences in the limited space of a classical Chinese garden. This leads to the sense that the garden’s scale is much larger than it really is. A main reason for this perceptual bias is the gardener’s manipulation of visual information. Most studies have discussed this phenomenon in terms of qualitative description with fragmented perspectives taken from static points, without considering ambient visual information or continuously changing observation points. A general question (...) arises, then, on why depth perception can vary from one observation point to another along a garden path. To better understand the spatial experience in classical Chinese gardens, this study focused on variations in perceived depth among different observation points and aimed to identify influential visual information through psychophysical experimentation. As stimuli for the experiment, panoramic photos of Liu garden were taken from three positions at Lvyin Pavilion. Considering the effects of pictorial visual cues on depth perception, the photos were processed to create 18 kinds of stimuli. Two tasks were presented to the participants. In Task 1, 71 participants were asked to rate the depth value of the garden using the magnitude estimation method in a cave automatic virtual environment. Statistical analysis of Task 1 revealed that depth values differed significantly among different viewpoints. In Task 2, participants were asked to compare 18 stimuli and 3D images presented on three connected monitors and to judge the depth of the garden using the adjustment method. The results of Task 2 again showed that depth values differed significantly among different viewpoints. In both tasks, ambient information significantly influenced depth perception. (shrink)

The study of cases of illusory or unstable perception of some visual stimuli allows exploration of the psychology of perception of the surrounding world. The wired construction known as “Necker cube” is one such stimulus: it can be perceived as a cube whose front face is seen higher than the back face or vice versa. The switch can occur intentionally or spontaneously. The investigations were focused on switching parameters, relation of the switching to eye position, pre-history, and environment. Here we (...) define that the kernel of the problem is recognizing the 2D drawing as a 3D Necker cube. To this end, we have expanded Gestalt's psychology methods that allow us to recognize 2D figures in drawings for recognizing 3D figure in a flat drawing (including the Necker cube). The presented algorithm for recognizing the cube based on the imitation principle allowed the development of the model of switching between two possible perceptions of the Necker cube. The paper shows that the predictions are in conformity with previously available experimental data. The results confirm the imitation principle of perception, and suggest expanding our research on perception to a wider class of 3D figures, opening a window into the internal processes of perception. (shrink)

Specular reflections and refractive distortions are complex image properties of solid transparent objects, but despite this complexity, we readily perceive the 3D shapes of these objects. We have found in past work that relevant sources of scene complexity have differential effects on 3D shape perception, with specular reflections increasing perceived thickness, and refractive distortions decreasing perceived thickness. In an object with both elements, such as glass, the two optical properties may complement each other to support reliable perception of 3D shape. (...) We investigated the relative dominance of specular reflection and refractive distortions in the perception of shape. Surprisingly, the ratio of specular reflection to refractive component was almost equal to that of ordinary glass and ice, which promote correct percepts of 3D shape. The results were also explained by the variance in local RMS contrast in stimulus images but may depend on overall luminance and contrast of the surrounding light field. (shrink)

Researchers have long debated the extent to which an individual’s skin tone influences their perceived race. Brooks and Gwinn demonstrated that the race of surrounding faces can affect the perceived skin tone of a central target face without changing perceived racial typicality, suggesting that skin lightness makes a small contribution to judgments of race compared to morphological cues. However, the lack of a consistent light source may have undermined the reliability of skin tone cues, encouraging observers to rely disproportionately on (...) morphological cues instead. The current study addresses this concern by using 3D models of male faces with typically Black African or White European appearances that are illuminated by the same light source. Observers perceived target faces surrounded by White faces to have darker skin than those surrounded by Black faces, particularly for faces of intermediate lightness. However, when asked to judge racial typicality, a small assimilation effect was evident, with target faces perceived as more stereotypically White when surrounded by White than when surrounded by Black faces at intermediate levels of typicality. This evidence of assimilation effects for perceived racial typicality despite concurrent contrast effects on perceived skin lightness supports the previous conclusion that perceived skin lightness has little influence on judgments of racial typicality for racially ambiguous faces, even when lighting is consistent. (shrink)

Although acoustic frequency is not a spatial property of physical objects, in common language, pitch, i.e., the psychological correlated of frequency, is often labeled spatially (i.e., “high in pitch” or “low in pitch”). Pitch-height is known to modulate (and interact with) the response of participants when they are asked to judge spatial properties of non-auditory stimuli (e.g., visual) in a variety of behavioral tasks. In the current study we investigated whether the modulatory action of pitch-height extended to the haptic estimation (...) of height of a virtual step. We implemented a HW/SW setup which is able to render virtual 3D objects (stair-steps) haptically through a PHANTOM device, and to provide real-time continuous auditory feedback depending on the user interaction with the object. The haptic exploration was associated with a sinusoidal tone whose pitch varied as a function of the interaction point’s height within (i) a narrower and (ii) a wider pitch range, or (iii) a random pitch variation acting as a control audio condition. Explorations were also performed with no sound (haptic only). Participants were instructed to explore the virtual step freely, and to communicate height estimation by opening their thumb and index finger to mimic the step riser height, or verbally by reporting the height in centimeters of the step riser. We analyzed the role of musical expertise by dividing participants into non musicians and musicians. Results showed no effects of musical pitch on high-realistic haptic feedback. Overall there is no difference between the two groups in the proposed multimodal conditions. Additionally, we observed a different haptic response distribution between musicians and non musicians when estimations of the auditory conditions are matched with estimations in the no sound condition. (shrink)

Computational theories of vision typically rely on the analysis of two aspects of human visual function: (1) object and shape recognition (2) co-calibration of sensory measurements. Both these approaches are usually based on an inverse-optics model, where visual perception is viewed as a process of inference from a 2D retinal projection to a 3D percept within a Euclidean space schema. This paradigm has had great success in certain areas of vision science, but has been relatively less successful in understanding perceptual (...) representation, namely, the nature of the perceptual encoding. One of the drawbacks of inverse-optics approaches has been the difficulty in defining the constraints needed to make the inference computationally tractable (e.g. regularity assumptions, Bayesian priors, etc.). These constraints, thought to be learned assumptions about the nature of the physical and optical structures of the external world, have to be incorporated into any workable computational model in the inverse-optics paradigm. But inference models that employ an inverse optics plus structural assumptions approach inevitably result in a na. (shrink)

The segregation of image parts into foreground and background is an important aspect of the neural computation of 3D scene perception. To achieve such segregation, the brain needs information about border ownership; that is, the belongingness of a contour to a specific surface represented in the image. This article presents psychophysical data derived from 3D percepts of figure and ground that were generated by presenting 2D images composed of spatially disjoint shapes that pointed inward or outward relative to the (...) continuous boundaries that they induced along their collinear edges. The shapes in some images had the same contrast (black or white) with respect to the background gray. Other images included opposite contrasts along each induced continuous boundary. Psychophysical results demonstrate conditions under which figure-ground judgment probabilities in response to these ambiguous displays are determined by the orientation of contrasts only, not by their relative contrasts, despite the fact that many border ownership cells in cortical area V2 respond to a preferred relative contrast. Studies are also reviewed in which both polarity-specific and polarity-invariant properties obtain perceptual figure-ground grouping results. The FACADE and 3D LAMINART models are used to explain these data. Keywords: figure-ground separation, border ownership, perceptual grouping, surface filling-in, V2, V4, FACADE Theory. (shrink)

According to the decomposition thesis, perceptual experiences resolve without remainder into their different modality-specific components. Contrary to this view, I argue that certain cases of multisensory integration give rise to experiences representing features of a novel type. Through the coordinated use of bodily awareness—understood here as encompassing both proprioception and kinaesthesis—and the exteroceptive sensory modalities, one becomes perceptually responsive to spatial features whose instances couldn’t be represented by any of the contributing modalities functioning in isolation. I develop an argument for (...) this conclusion focusing on two cases: 3D shape perception in haptic touch and experiencing an object’s egocentric location in crossmodally accessible, environmental space. (shrink)

Do contemporary big-budget blockbuster films like Gravity move something in us that is fundamentally the same as what avant-garde and experimental films have done for more than a century? In a powerful challenge to mainstream film theory, Cinema's Bodily Illusions demonstrates that this is the case. Scott C. Richmond bridges genres and periods by focusing, most palpably, on cinema's power to evoke illusions: feeling like you're flying through space, experiencing 3D without glasses, or even hallucinating. He argues that cinema is, (...) first and foremost, a technology to modulate perception. He presents a theory of cinema as a proprioceptive technology: cinema becomes art by modulating viewers' embodied sense of space. It works primarily not at the level of the intellect but at the level of the body. Richmond develops his theory through examples of direct perceptual illusion in cinema: hallucinatory flicker phenomena in Tony Conrad's The Flicker, eerie depth effects in Marcel Duchamp's Anémic Cinéma, the illusion of bodily movement through onscreen space in Stanley Kubrick's 2001, Godfrey Reggio's Koyaanisqatsi, and Alfonso Cuarón's Gravity. In doing so he combines insights from Maurice Merleau-Ponty's phenomenology of perception and James J. Gibson's ecological approach to perception. The result is his distinctive ecological phenomenology, which allows us to refocus on the cinema's perceptual, rather than representational, power. Arguing against modernist habits of mind in film theory and aesthetics, and the attendant proclamations of cinema's death or irrelevance, Richmond demonstrates that cinema's proprioceptive aesthetics make it an urgent site of contemporary inquiry. (shrink)

3D FORMOTION, a unified cortical model of motion integration and segmentation, explains how brain mechanisms of form and motion processing interact to generate coherent percepts of object motion from spatially distributed and ambiguous visual information. The same cortical circuits reproduce motion-induced distortion of position maps, including both flash-lag and flash-drag effects.

This paper proposes a novel experimental approach that would help to determine whether perspectival shapes, such as the elliptical profile of a tilted plate or coin, are part of perceptual experience. If they are part of perceptual experience, then it should be possible to identify these shapes simply by attending appropriately to them. Otherwise, in order to identify perspectival shapes they must first be constructed in the visual imagination. We propose that these accounts of perspectival identification can be tested by (...) measuring the interference between visual and verbal working memory load, respectively, and the identification of perspectival shapes in the appearance of a 3D object. (shrink)

The article deals with the structure and function of perceptual judgment in the perception theories of the Buddhist Diṅṅāga and the Vaiśeṣika Praśastapāda. I show their indebtedness to the Vyākaraṇa tradition and particularly to Patañjali. Following Shōryū Katsura’s idea that the status of perceptual judgment with regard to the Buddhist system of instruments of valid cognition was first established by Dharmakīrti, I argue that Diṅṅāga’s examples in his definition of perception in Pramāṇasamuccaya-vṛtti I,3d could be considered as perceptual judgments in (...) the sense of Charles Peirce. After the examination of Diṅṅāga’s and Praśastapāda’s examples of perceptual judgments, I come to the conclusion that Diṅṅāga, as a nominalist, sees in them an expression of ordinary linguistic behaviour shaped by convention and grammatical tradition, while Praśastapāda, as a realist, seeks to show that perceptual judgments follow the Vaiśeṣika ontological categories. If in Diṅṅāga’s epistemology perceptual judgement remains outside the pramāṇa system, in Praśastapāda’s Vaiśeṣika it pertains to the pramāṇa of perception. (shrink)

Often implicit in visual display design and development is a gold standard of photorealism. By approximating direct perception, photorealism appeals to users and designers by being both attractive and apparently effortless. The vexing result from numerous performance evaluations, though, is that increasing realism often impairs performance. Smallman and St. John (2005) labeled misplaced faith in realistic information display Naïve Realism and theorized it resulted from a triplet of folk fallacies about perception. Here, we illustrate issues associated with the wider trend (...) towards realism by focusing on a specific current trend for high-fidelity perspective view (3D) geospatial displays. In two experiments, we validated Naïve Realism for different terrain understanding tasks, explored whether certain individuals are particularly prone to Naïve Realism, and determined the ability of task feedback to mitigate Naïve Realism. Performance was measured for laying and judging a concealed route across realistic terrain shown in different display formats. Task feedback was either implicit, in Experiment 1, or explicit in Experiment 2. Prospective and retrospective intuitions about the best display formats for the tasks were recorded and then related to task performance and participant spatial ability. Participants generally intuited they would perform tasks better with more realism than they actually required. For example, counter to intuitions, lowering fidelity of the terrain display revealed the gross scene layout needed to lay a well-concealed route. Individuals of high spatial ability calibrated their intuitions with only implicit task feedback, whereas those of low spatial ability required salient, explicit feedback to calibrate their intuitions about display realism. Results are discussed in the wider context of applying perceptual science to display design, and combating folk fallacies. (shrink)

The laws and principles which predict how perceptual qualities can be extracted from the most elementary visual signals were discovered by the Gestalt psychologists(e.g., Wertheimer,1923; Metzger,1930, translated and re-editedbySpillmann in 2009 and2012, respectively). Their seminal work has inspired visual science ever since, andhas led to exciting discoveries which have confirmed the Gestalt idea that the human brain would have an astonishing capacity for selecting and combining critical visual signals to generate output representations for decision making and action. This capacity of (...) selection and integration enables the perception of form and space, and the correct estimation of relative positions, trajectories, and distances of objects represented in planar images. This paper addresses problems of perceptual organization with critical implications for visual interfaces, and the design of surgical simulator platforms in particular. (shrink)

Pictures are 2D surfaces designed to elicit 3D-scene-representing experiences from their viewers. In this essay, I argue that philosophers have tended to underestimate the relevance of research in vision science to understanding the nature of pictorial experience. Both the deeply entrenched methodology of virtual psychophysics as well as empirical studies of pictorial space perception provide compelling support for the view that pictorial experience and seeing face-to-face are experiences of the same psychological, explanatory kind. I also show that an empirically informed (...) account of pictorial experience provides resources to develop a novel, resemblance-based account of depiction. According to what I call the deep resemblance theory, pictures work by presenting virtual models of objects and scenes in phenomenally 3D, pictorial space. (shrink)

Therapeutic strategies capable of inducing and enhancing prosthesis embodiment are a key point for better adaptation to and acceptance of prosthetic limbs. In this study, we developed a training protocol using an EMG-based human-machine interface that was applied in the preprosthetic rehabilitation phase of people with amputation. This is a case series with the objective of evaluating the induction and enhancement of the embodiment of a virtual prosthesis. Six men and a woman with unilateral transfemoral traumatic amputation without previous use (...) of prostheses participated in the study. Participants performed a training protocol with the EMG-based HMI, composed of six sessions held twice a week, each lasting 30 mins. This system consisted of myoelectric control of the movements of a virtual prosthesis immersed in a 3D virtual environment. Additionally, vibrotactile stimuli were provided on the participant’s back corresponding to the movements performed. Embodiment was investigated from the following set of measurements: skin conductance response, crossmodal congruency effect, ability to control the virtual prosthesis, and reports before and after the training. The increase in the skin conductance response in conditions where the virtual prosthesis was threatened, recalibration of the peripersonal space perception identified by the crossmodal congruency effect, ability to control the virtual prosthesis, and participant reports consistently showed the induction and enhancement of virtual prosthesis embodiment. Therefore, this protocol using EMG-based HMI was shown to be a viable option to achieve and enhance the embodiment of a virtual prosthetic limb. (shrink)

A coin rotating back in depth in some sense presents a changing, elliptical shape. How are we to understand such (in this case) ‘appearances of ellipticality’? How is the experiential sense of such shifting shape appearances related to the experiential sense of enduring shape definitive of perceived shape constancy? Is the experiential recovery of surface shape based on the prior (perhaps more fundamental) recovery of point or element 3D spatial locations?—or is the perception of shape a largely independent perceptual achievement? (...) Do we gain access to enduring shape properties by first detecting and working from ‘shape appearances’? These are some of the topics taken up in this paper. (shrink)

Psychology and philosophy have long reflected on the role of perspective in vision. Since the dawn of modern vision science—roughly, since Helmholtz in the late 1800s—scientific explanations in vision have focused on understanding the computations that transform the sensed retinal image into percepts of the three-dimensional environment. The standard view in the science is that distal properties—viewpoint-independent properties of the environment (object shape) and viewpoint-dependent relational properties (3D orientation relative to the viewer)–are perceptually represented and that properties of the (...) proximal stimulus (in vision, the retinal image) are not. This view is woven into the nature of scientific explanation in perceptual psychology, and has guided impressive advances over the past 150 years. A recently published article suggests that in shape-perception, the standard view must be revised. It argues, on the basis of new empirical data, that a new entity—perspectival shape—should be introduced into scientific explanations of shape perception. Specifically, the article’s centrally advertised claim is that, in addition to distal shape, perspectival shape is perceived. We argue that this claim rests on a series of mistakes. Problems in experimental design entail that the article provides no empirical support for any claims regarding either perspective or the perception of shape. There are further problems in scientific reasoning and conceptual development. Detailing these criticisms and explaining how science treats these issues is meant to clarify method and theory, and to improve exchanges between the science and philosophy of perception. (shrink)

Over a decade ago, I introduced a large-scale theory of the cognitive brain which explained for the first time how the human brain is able to create internal models of its intimate world and invent models of a wider universe. An essential part of the theoretical model is an organization of neuronal mechanisms which I have named the Retinoid Model (Trehub, 1977, 1991). This hypothesized brain system has structural and dynamic properties enabling it to register and appropriately integrate disparate foveal (...) stimuli into a perspectival, egocentric representation of an extended 3D world scene including a neuronally-tokened locus of the self which, in this theory, is the neuronal origin of retinoid space. As an integral part of the larger neuro-cognitive model, the retinoid system is able to perform many other useful perceptual and higher cognitive functions. In this paper, I draw on the hypothesized properties of this system to argue that neuronal activity within the retinoid structure constitutes the phenomenal content of consciousness and the unique sense of self that each of us experiences. -/- Trehub, A. (1977). Neuronal models for cognitive processes: Networks for learning, perception, and imagination. _Journal of Theoretical Biology_ 65: 141-169. -/- Trehub, A. (1991). _The Cognitive Brain_. MIT Press. -/- . (shrink)

Neuroarchitecture uses neuroscientific tools to better understand architectural design and its impact on human perception and subjective experience. The form or shape of the built environment is fundamental to architectural design, but not many studies have shown the impact of different forms on the inhabitants’ emotions. This study investigated the neurophysiological correlates of different interior forms on the perceivers’ affective state and the accompanying brain activity. To understand the impact of naturalistic three-dimensional (3D) architectural forms, it is essential to perceive (...) forms from different perspectives. We computed clusters of form features extracted from pictures of residential interiors and constructed exemplary 3D room models based on and representing different formal clusters. To investigate human brain activity during three-dimensional perception of architectural spaces, we used a mobile brain/body imaging (MoBI) approach recording the electroencephalogram (EEG) of participants while they naturally walk through different interior forms in virtual reality (VR). The results revealed a strong impact of curvature geometries on activity in the anterior cingulate cortex (ACC). Theta band activity in ACC correlated with specific feature types (rs (14) = 0.525, p = 0.037) and geometry (rs (14) = - 0.579, p = 0.019), providing evidence for a role of this structure in processing architectural features beyond their emotional impact. The posterior cingulate cortex and the occipital lobe were involved in the perception of different room perspectives during the stroll through the rooms. This study sheds new light on the use of mobile EEG and VR in architectural studies and provides the opportunity to study human brain dynamics in participants that actively explore and realistically experience architectural spaces. (shrink)

How do we recognize identities between seen shapes and felt ones? Is this due to associative learning, or to intrinsic connections these sensory modalities? We can address this question by testing the capacities of newly sighted subjects to match seen and felt shapes, but only if it is shown that the subjects can see the objects well enough to form adequate visual representations of their shapes. In light of this, a recent study by R. Held and colleagues fails to demonstrate (...) that their newly sighted subjects’ inability to match seen and felt shape was due to a lack of intermodal connections rather than a purely visual deficit, as they may not have been able visually to represent 3D shape in the perspective-invariant way required for intermodal matching. However, the study could be modified in any of several ways to help avoid this problem. (shrink)

Perceptual neuroscience has identified mechanisms of perceptual grouping which account for the ways in which visual sensitivity to ordered structure and regularities expresses itself, in behavior and in the brain. The need to actively construct order, notably representations of objects in depth, is mandated as soon as visual signals reach the retina, given the occlusion of retinal signals by retinal veins and other retinal elements or blur. Multiple stages of neural processing transform fragmented signals into visual key representations of 3D (...) scenes that can be used to control effective behaviors. Since our survival depends on our ability to pick up order in the physical world, and since we conceive the physical world as an ordered one, our perception must somehow be sensitive to order. The articles from this collection illustrate how texture dissimilarity, boundary completion, surface filling-in, and figure-ground segregation generate perceptual order. (shrink)

You might reasonably surmise from the title of this paper that I will be discussing a theory of vision. After all, what is a theory of vision but a theory of how the world is connected to our visual representations? Theories of visual perception universally attempt to give an account of how a proximal stimulus (presumably a pattern impinging on the retina) can lead to a rich representation of a three dimensional world and thence to either the recognition of known (...) objects or to the coordination of actions with visual information. Such theories typically provide an effective (i.e., computable) mapping from a 2D pattern to a representation of a 3D scene, usually in the form of a symbol structure. But such a mapping, though undoubtedly the essential purpose of a theory of vision, leaves at least one serious problem that I intend to discuss here. It is this problem, rather than a theory of vision itself, that is the subject of this talk. (shrink)

This article defends the claim that a significant part of visual perception (called “early vision”) is impervious to the influence of beliefs, expectations or knowledge. We examine a wide range of empirical evidence that has been cited in support of the continuity of vision and cognition and argue that the evidence either shows within- vision top-down effects, or else the extra-visual effects that are demonstrated occur before the operation of the autonomous early vision system (through the allocation of focal attention) (...) or after the visual system has produced its 3D shape-description (through the intervention of post-visual decision processes). (shrink)

Taking technological developments in urban mapping and the megacity phenomena of rapid change and sprawling space as its starting point, this essay provides a history of the present through a genealogy of maps of Montpellier in France, a rapidly growing modern city that provides examples from the earliest printed maps of the 16th century through to the most recent innovations in public-sponsored 3D mapping. By tracing the shifting correlations of narrative elements, it places in historical perspective the relationship between those (...) concepts, such as verticality and horizontality, and perception and representation, which are problematized in the contemporary contexts of megacities and digital technology. (shrink)

Much working time is spent in meetings and, as a consequence, meetings have become the subject of multidisciplinary research. Virtual Meeting Rooms (VMRs) are 3D virtual replicas of meeting rooms, where various modalities such as speech, gaze, distance, gestures and facial expressions can be controlled. This allows VMRs to be used to improve remote meeting participation, to visualize multimedia data and as an instrument for research into social interaction in meetings. This paper describes how these three uses can be realized (...) in a VMR. We describe the process from observation through annotation to simulation and a model that describes the relations between the annotated features of verbal and non-verbal conversational behavior. As an example of social perception research in the VMR, we describe an experiment to assess human observers’ accuracy for head orientation. (shrink)

This paper presents an ethnomethodological analysis of the representation of space in hand-drawn maps. The rendering practice of hand drawn maps includes some systematic devices by which real space is transformed into two-dimensional space on paper and a map is recognized as the map representing a certain space. In other words, members use these devices not only to trace real space but also to enable the recognition of space in a specific mode. The paper deals with three distinctive patterns affording (...) accountability of geographical features: retention of the three-dimensionality of real space; formal resemblance with intertextuality; and identification of space by means of words. Retention of the 3D of space on map is the device that assigns 3D effect to maps and contributes to the perception of the figure as being similar to real space. Intertextuality bestows formal resemblance on various maps to secure the intersubjectivity and scientific objectivity of maps. Words entered on hand-drawn maps enable a reading of a correspondence of maps with real space. The representation of space makes sense by virtue of these devices that accomplish the recognizability of space between the drawers and readers of hand-drawn maps. (shrink)

Cyberspace, a term popularized in the 1984 novel Neuromancer, was used by William Gibson to describe the ‘consensual hallucination’ and interstitial online world that lies between the reality of our world and that of the surreal terrain of dreamscapes. While many attempts have been made to describe this intangible, yet seemingly perceptible space, the digital domain as a metaphor mirrors in many ways our own inadequate understanding of consciousness. Conversely, the physicist Michio Kaku explains that our reality is bounded by (...) hyperspace – a multi-dimensioned space beyond our quotidian 3D existence that runs parallel, or tangential, to us along with the phenomenon of time. Indeed, if space and time (here considered as space–time) are a consolidated whole in the physical sense, perhaps our consciousness, as a structure manifest within this continuum may itself be thought of as a sensorial projection of this amalgam that attempts to observe and make sense, or meaning, of this condition. In truth, what if our need and delight in storytelling is driven by the evolution of our biology, as well as our impulse to locate our place in the universe? This article will attempt to examine and delimit the narrative confines of space–time as an appeal to, and an endeavour at, uncovering the alterity of storytelling as a function of consciousness. It will visit the realms of the holograph, quantum mechanics, virtual and augmented realities, as well as other scientific and philosophical tracts as a means to investigate and explore the physiology of space and our imperative desire to share stories. (shrink)