Research on the Influence of Visual Illusion between Visually Perceived System and Visually Guided Action System

The brain represents the state of the world around us based upon a stream of ambiguous sensory data. This requires the integration of different sources of information, including information received from different sense modalities, and information drawn from past experience. Bayesian theories of perception provide an approach to characterising how systematic differences in the probabilistic integration of information in the brain may underlie the differences that occur between individuals in their perceptual experience. The present thesis explores how perceptual, motor and social aspects of autism spectrum disorder (ASD) may emerge from variation in the neurocognitive processes described by Bayesian theories. A focus is on the predictive processing model of brain function, which links Bayesian theories of perception to neural mechanisms. The thesis includes empirical studies that examine perceptual, sensorimotor and cognitive aspects of ASD. ASD and nonclinical autistic traits are first examined in the context of body perception; concerning, specifically, how the brain represents the state of the limbs based on visual, tactile and proprioceptive information, and how this sensory information is integrated with prior expectations regarding the body. These processes are investigated using a multisensory perceptual illusion: the rubber hand illusion. ASD is associated with a largely typical perceptual experience of this illusion, indicating intact multisensory integration in the context of body representation. A reduced influence of the illusion on motor function, however, supports a difference in ASD in the integration of expectations for limb position (influenced by the illusion) with conflicting sensory (proprioceptive) signals. The integration of incoming information with existing expectations about the environment is also examined in the context of statistical learning. A computerised task is developed to assess the integration of iterative feedback with prior information as participants predict the location of a noisy set of visual markers. The hypothesis tested is that features of ASD are associated with a persistently higher weighting of incoming information in driving inference, at the expense of expectations developed from recent experience; in this more cognitive context, these data provide evidence against this hypothesis, suggesting that a more context-dependent atypicality in information processing in ASD is more likely than that initially hypothesised. The thesis also develops theoretical and philosophically-relevant treatments of how the symptoms of ASD may emerge from differences in brain function characterised within a Bayesian framework. This includes drawing on recent theoretical developments regarding the role of volatility processing and action in maintaining optimal inference on the environment. In addition, models of Bayesian inference in the brain can be extended to the social domain. For instance, the process of representing the mental states of other people (i.e., theory of mind) can be cast in terms of implicit inference on the external causes of sensory signals. In light of these expanded models of predictive processing, the differences in information processing hypothesised to occur in ASD have implications not just for perception, but also for motor behaviours, social cognition and social interaction. The overall view that emerges is that diverse aspects of ASD may be captured in terms of how incoming sensory signals are integrated, in a probabilistic manner, with the brain’s hierarchical and multimodal model of its environment. A promising direction for this field is in developing this idea in the context of action (i.e., active inference) and more recent models of how the brain estimates the optimal weighting of sensory information. This area of research has the potential to provide a nuanced perspective on the neurocognitive basis of ASD and the relationship between sensory mechanisms and autistic behaviours.

Visual size illusions have been shown to affect perceived object size but not the aperture of the hand when reaching to those same objects. Thus, vision for perception is said to be dissociated from vision for action. The present study examines the effect of visual-position and visual-shape illusions on both the visually perceived center of an object and the position of a grasp on that object when a balanced lift is required. The results for both experiments show that although the illusions influence both the perceived and the grasped estimates of the center position, the grasp position is more veridical. This partial dissociation is discussed in terms of its implications for streams of visual processing.

Luria (Luria, Cognitive development: Its cultural and social foundations, Harvard University Press, 1976) famously observed that people who never learnt to read and write do not perceive visual illusions. We conducted a conceptual replication of the Luria study of the effect of literacy on the processing of visual illusions. We designed two carefully controlled experiments with 161 participants with varying literacy levels ranging from complete illiterates to high literates in Chennai, India. Accuracy and reaction time in the identification of visual shape and color illusions and the identification of appropriate control images were measured. Separate statistical analyses of Experiments 1 and 2 as well as pooled analyses of both experiments do not provide any support for the notion that literacy affects the perception of visual illusions. Our large sample, carefully controlled study strongly suggests that literacy does not meaningfully affect the identification of visual illusions and raises some questions about other reports of cultural effects on illusion perception.

Animated optical illusions – how to effectively create them and how they are perceived

A Visual Information System represents a radical departure from the rigid text-in/text out paradigm of conventional Information Systems. It significantly enlarges the applications scope of information systems and typically sits on top of a general purpose multimedia operating system supported by multimedia hardware and a high bandwidth network. Unlike a conventional Information System, the types of storage and I/O devices required to support a Visual Information System generally include a much greater variety of facilities for efficient visual information presentation and visualisation. Apart from providing multi-mode delivery, the effective correlation between information of the same media type and information belonging to different media types forms an integral part of such systems. The essential building blocks of a Visual Information System are described, and the management of different types of information contents are discussed.KeywordsDatabase Management SystemQuery ModelVisual QueryVideo Object PlaneCriminal ProfileThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

The science and technology of image transmission and display has evolved primarily from the diciplines of computer science, electrical engineering and physics. Thus, it is only natural that techniques and attitudes which have developed are characterized by the style in which people in these areas approach the subject of images and their transmission, display, and processing. For example, one finds many important differences between the methods of television and those of photography. Moreover, an even greater contrast is found when comparing the methods of electrical engineering, physics, television and photography with those now understood to be employed by the human eye and the human visual system. Specifically, let us contrast the method by which television, photography and the human visual system, represent image information. In television (particularly digital imaging), image values are represented by signals analogous to quantities of light. They are called intensities. In photography, on the other hand, the representing quantities are concentrations of silver or dyes. Consequently, due to the natural exponentiating laws governing the interaction of light with these media, they are analogous to the logarithm of quantities of light. They are called densities. The human visual system, on the other hand, (while being generally logarithmically sensitive) moves a large step further away from representation by physical quantities of light and produces at very early stages in its processing highly modified versions of the patterns of light or their logarithms. The natural question then arrises, why should the human visual system try to do this; and since it does, what consequences are implied in terms of the television and photographic presentations normally employed?

Visual information systems contain a substantial amount of non-alphanumeric information, and represent a radical departure from the largely text-based paradigm of conventional information systems. For the effective operation of an information system, data search and management mechanisms play a pivotal role, and a key requirement of such a system is the ability to search and locate information much more efficiently than a manual approach. However, for a visual information system where most data and relationships are non-alphanumeric, locating the correct information poses a new challenge. In particular, the database characteristics and storage structures required to support a visual information system are substantially different from those for a conventional information system. Here, the principal functions and components of a database management system for the effective management of visual information are presented.

Recently MR (Mixed Reality) techniques are used in many fields, and one of them is work support. Work support using MR techniques can display work instructions directly in the work space and help user to work effectively especially in assembling tasks. MR work support for assembling tasks often uses HMD (Head Mounted Display) to construct MR environment. However, there are some problems for the use of HMD, such as a burden to the head, a narrow view and a motion picture sickness. One of the techniques to solve such problems is pepper's ghost which is an optical illusion using a glass. In this paper, we propose the naked eye MR work supporting system for assembling tasks using pepper's ghost. This system enables a beginner to assemble some blocks into one object by the naked eye with a few burdens.

It is proposed the visual information structures formation model for the visual information systems processing. Unlike the known models this model simultaneously takes into account the transformation of geospatial coordinates into coordinates of the visual information structure and the transformation of brightness. Also provides the ability to correctly process and analyze the visual information structures in the visual information systems.

Visual illusions are fascinating because visual perception misjudges the actual physical properties of an image or a scene. This paper examines the perception of visual illusions in three-dimensional space. Six diverse visual illusions were implemented for both immersive virtual reality and monitor based environments. A user-study with 30 healthy participants took place in laboratory conditions comparing the perceptual effects of the two different mediums. Experimental data were collected from both a simple ordering method and electrical activity of the brain. Results showed unexpected outcomes indicating that only some of the illusions have a stronger effect in immersive virtual reality, others in monitor based environments while the rest with no significant effects.

Two experiments are reported in which a decrement in the magnitude of the Muller-Lyer illusion was found if free eye movements were allowed. Little or no decrement was obtained if Ss fixated one point of the figure during inspection. In one experiment eye movements were recorded. Saccades across the perceptually short side of the Muller-Lyer figure were found to be shorter than across the perceptually long side. After inspection with free eye movements, the saccades became more nearly equal on the two sides. Such changes in eye movements did not occur if Ss fixated one point during the inspection period. The data are interpreted in terms of perception being determined by the efferent readiness activated by visual input. According to this interpretation, the decrement in the magnitude of the illusion results from recalibration of the efferent programs.

Perceptual illusions refer to systematically oriented errors in the perception of figures or scenes, and these errors are observed in almost all people. For centuries, they have been called ‘opto-geometric illusions’ because it was thought that they concerned only visual perception. Although visual errors are relatively rare, comments and questions about visual illusions are found as early as in the Greek and Roman literature. In scientific psychology, the theoretical and practical problems raised by these deformations have been intensively studied since the end of the 19th Century, and the elements of the figure inducing each error are now identified. However, there is no general theory explaining all the visual illusions. Instead, each figure must be analysed in order to determine the specific processes leading to the error. KeywordsVisual IllusionPerceptual ErrorHaptic PerceptionExploratory MovementPonzo IllusionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Systematic review of visual illusions in schizophrenia

2 - The human visual system described through visual illusions

Psychological research has shown that cognitive illusions, of which visual illusions are just a special case, are systematic and pervasive, raising epistemological questions about how error in all forms of research can be identified and eliminated. The quantitative sciences make use of statistical techniques for this purpose, but it is not clear what the qualitative equivalent is, particularly in view of widespread scepticism about validity and objectivity. I argue that, in the light of cognitive psychology, the 'error question' cannot be dismissed as a positivist obsession, and that the concepts of truth and objectivity are unavoidable. However, they constitute only a 'minimal realism', which does not necessarily bring a commitment to 'absolute' truth, certainty, correspondence, causation, reductionism, or universal laws in its wake. The assumption that it does reflects a misreading of positivism and, ironically, precipitates a 'crisis of legitimation and representation', as described by constructivist authors.