The multisensory body revealed through its cast shadows

One key issue when conceiving the body as a multisensory object is how the cognitive system integrates visible instances of the self and other bodies with one\u2019s own somatosensory processing, to achieve self-recognition and body ownership. Recent research has strongly suggested that shadows cast by our own body have a special status for cognitive processing, directing attention to the body in a fast and highly specific manner. The aim of the present article is to review the most recent scientific contributions addressing how body shadows affect both sensory/perceptual and attentional processes. The review examines three main points: (1) body shadows as a special window to investigate the construction of multisensory body perception; (2) experimental paradigms and related findings; (3) open questions and future trajectories. The reviewed literature suggests that shadows cast by one\u2019s own body promote binding between personal and extrapersonal space and elicit automatic orienting of attention toward the bodypart casting the shadow. Future research should address whether the effects exerted by body shadows are similar to those observed when observers are exposed to other visual instances of their body. The results will further clarify the processes underlying the merging of vision and somatosensation when creating body representations

Perceptual organization and its influence upon attention

Humans are able to control so much of their environment not through brute strength or enhanced sensory receptors, but through our ability to understand the world around us. In order to make sense of the world around us we need to organize the information that our sensory systems receive. One of the most fundamental steps in this organizational process lies in the construction of objects. By breaking down our sensory input into objects the mind provides a basis upon which it can begin to scaffold our understanding of the world. This thesis therefore explores the basic stages at which the visual system organizes our sensory input into distinct objects. It explores these stages by exploiting the fact that the brain’s limited processing resources can be selectively allocated on the basis of ‘object-hood’. This allocation of processing resources, or attention, on the basis of these early stages of segmentation is commonly referred to as ‘object based attention’. ‘Object based attention’ and perceptual organisation are explored in three sections in this thesis: Understanding the Phenomenon of Object Based Attention. The first three chapters of this thesis seeks to further our understanding of the phenomenon of ‘object based attention’, for example, chapter 3 explores whether the visual system can simultaneously parse several objects as potential units of attention, or whether it can only segment one or two objects at a time. Object Based Attention, a Tool to Explore the Nature of Perceptual Organisation The second section of this thesis attempts to use the phenomenon of ‘object based attention’ as a tool to explore the nature of perceptual representations, for example chapter 5 tests whether different modalities (in particular vision and touch) are able to directly share information about objects in order to build up an integrated model of the external world. Object Based Attention, Perceptual Organisation and Shape Processing Area LO. In the final section of this thesis the nature of perceptual organization is explored in a patient with a very specific form of brain damage that enables us to ask what areas of the brain are critically required for different aspects of perceptual organization

Visual glue

technical reportOne key function of graphics systems is to present information about the 3-D structure of modeled environments. For real-time simulations, conveying a sense of contact between touching surfaces and relative position and motion between proximate objects is particularly critical. Neither stereo nor occlusion cues are completely effective for such fine judgments. Conventional wisdom often argues that shadows play a critical role. Less often, it is argued that interreflection also contributes to the sense that two surfaces are touching. This paper explores the actual utility of shadows and interreflection in signaling contact and suggests how this information can be exploited in real-time rendering systems to glue objects to surfaces

An Empirical Evaluation of Visual Cues for 3D Flow Field Perception

Three-dimensional vector fields are common datasets throughout the sciences. They often represent physical phenomena that are largely invisible to us in the real world, like wind patterns and ocean currents. Computer-aided visualization is a powerful tool that can represent data in any way we choose through digital graphics. Visualizing 3D vector fields is inherently difficult due to issues such as visual clutter, self-occlusion, and the difficulty of providing depth cues that adequately support the perception of flow direction in 3D space. Cutting planes are often used to overcome these issues by presenting slices of data that are more cognitively manageable. The existing literature provides many techniques for visualizing the flow through these cutting planes; however, there is a lack of empirical studies focused on the underlying perceptual cues that make popular techniques successful. The most valuable depth cue for the perception of other kinds of 3D data, notably 3D networks and 3D point clouds, is structure-from-motion (also called the Kinetic Depth Effect); another powerful depth cue is stereoscopic viewing, but none of these cues have been fully examined in the context of flow visualization. This dissertation presents a series of quantitative human factors studies that evaluate depth and direction cues in the context of cutting plane glyph designs for exploring and analyzing 3D flow fields. The results of the studies are distilled into a set of design guidelines to improve the effectiveness of 3D flow field visualizations, and those guidelines are implemented as an immersive, interactive 3D flow visualization proof-of-concept application

Illuminating palaeolithic art using virtual reality: A new method for integrating dynamic firelight into interpretations of art production and use

Approaches to Palaeolithic art have increasingly shifted beyond the traditional focus on engraved or depicted forms in isolation, to appreciating the sensorial experience of art making as integral to shaping the form of depictions and the meaning imbued within them. This kind of research appreciates an array of factors pertinent to how the art may have been understood or experienced by people during the Palaeolithic, including placement, lighting, accessibility, sound, and tactility. This paper contributes to this “sensory turn” in Palaeolithic art research, arguing that the roving light cast by the naked flame of fires, torches or lamps is an important dimension in understanding artistic experiences. However, capturing these effects, whether during analysis, as part of interpretation, or presentation, can be challenging. A new method is presented in virtual reality (VR) modelling – applied to Palaeolithic art contexts for the first time - as a safe and non-destructive means of simulating dynamic light sources to facilitate analysis, interpretation, and presentation of Palaeolithic art under actualistic lighting conditions. VR was applied to two Magdalenian case studies: parietal art from Las Monedas (Spain) and portable stone plaquettes from Montastruc (France). VR models were produced using Unity software and digital models of the art captured via whitelight (Montastruc) and photogrammetric (Las Monedas) scans. The results demonstrate that this novel application of VR facilitates the testing of hypotheses related to the sensorial and experiential dimensions of Palaeolithic art, allowing discussions of these elements to be elevated beyond theoretical ideas

"What was Molyneux's Question A Question About?"

Molyneux asked whether a newly sighted person could distinguish a sphere from a cube by sight alone, given that she was antecedently able to do so by touch. This, we contend, is a question about general ideas. To answer it, we must ask (a) whether spatial locations identified by touch can be identified also by sight, and (b) whether the integration of spatial locations into an idea of shape persists through changes of modality. Posed this way, Molyneux’s Question goes substantially beyond question (a), about spatial locations, alone; for a positive answer to (a) leaves open whether a perceiver might cross-identify locations, but not be able to identify the shapes that collections of locations comprise. We further emphasize that MQ targets general ideas so as to distinguish it from corresponding questions about experiences of shape and about the property of tangible (vs. visual) shape. After proposing a generalized formulation of MQ, we extend earlier work (“Many Molyneux Questions,” Australasian Journal of Philosophy 2020) by showing that MQ does not admit a single answer across the board. Some integrative data-processes transfer across modalities; others do not. Seeing where and how such transfer succeeds and fails in individual cases has much to offer to our understanding of perception and its modalities

What was Molyneux's Question A Question About?

Molyneux asked whether a newly sighted person could distinguish a sphere from a cube by sight alone, given that she was antecedently able to do so by touch. This, we contend, is a question about general ideas. To answer it, we must ask (a) whether spatial locations identified by touch can be identified also by sight, and (b) whether the integration of spatial locations into an idea of shape persists through changes of modality. Posed this way, Molyneux’s Question goes substantially beyond question (a), about spatial locations, alone; for a positive answer to (a) leaves open whether a perceiver might cross-identify locations, but not be able to identify the shapes that collections of locations comprise. We further emphasize that MQ targets general ideas so as to distinguish it from corresponding questions about experiences of shape and about the property of tangible (vs. visual) shape. After proposing a generalized formulation of MQ, we extend earlier work (“Many Molyneux Questions,” Australasian Journal of Philosophy 2020) by showing that MQ does not admit a single answer across the board. Some integrative data-processes transfer across modalities; others do not. Seeing where and how such transfer succeeds and fails in individual cases has much to offer to our understanding of perception and its modalities

Irradiated Landscapes: Journey to Prospect Cottage

How does one map a memory of a place, a fragment of time, in a way that is as evocative and vivid as the initial experience? When we prospect a landscape, we witness it as it is now; light and shadow define it, complete with its current solar exposure, humidity and temperature. As we then move through the landscape our brains process this information, leading us to perceive something entirely new. Our memory of that perception is also rewritten each time we recall it. Intended as a process of design research – based at the late Derek Jarman’s Prospect Cottage on Dungeness beach in Kent, UK – this essay attempts to capture the fluidity of these perceived experiences and freeze them into sited mappings, unique to the temporal and climatic experience of the observer. Centered on the production of digitally-crafted ‘perceptual cartographies’, which are designed/generated from the site, it presents an exploration into ways of seeing architecture and landscape. In doing so, the essay calls for the recording of sites and designs in which emotional responses – induced by light – leave traces of the spaces in the individuals who visit them, creating a temporally sensitive and deeply perceptual experience of that place