Diagnostic Palpation in Osteopathic Medicine: A Putative Neurocognitive Model of Expertise

This thesis examines the extent to which the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Chapter 2 and Chapter 3 review, respectively, the literature on the role of analytical and non-analytical processing in osteopathic and medical clinical decision making; and the relevant research on the use of vision and haptics and the development of expertise within the context of an osteopathic clinical examination. The two studies reported in Chapter 4 examined the mental representation of knowledge and the role of analogical reasoning in osteopathic clinical decision making. The results reported there demonstrate that the development of expertise in osteopathic medicine is associated with the processes of knowledge encapsulation and script formation. The four studies reported in Chapters 5 and 6 investigate the way in which expert osteopaths use their visual and haptic systems in the diagnosis of somatic dysfunction. The results suggest that ongoing clinical practice enables osteopaths to combine visual and haptic sensory signals in a more efficient manner. Such visuo-haptic sensory integration is likely to be facilitated by top-down processing associated with visual, tactile, and kinaesthetic mental imagery. Taken together, the results of the six studies reported in this thesis indicate that the development of expertise in diagnostic palpation in osteopathic medicine is associated with changes in cognitive processing. Whereas the experts’ diagnostic judgments are heavily influenced by top-down, non-analytical processing; students rely, primarily, on bottom-up sensory processing from vision and haptics. Ongoing training and clinical practice are likely to lead to changes in the clinician’s neurocognitive architecture. This thesis proposes an original model of expertise in diagnostic palpation which has implications for osteopathic education. Students and clinicians should be encouraged to appraise the reliability of different sensory cues in the context of clinical examination, combine sensory data from different channels, and consider using both analytical and nonanalytical reasoning in their decision making. Importantly, they should develop their skills of criticality and their ability to reflect on, and analyse their practice experiences in and on action

Tactual perception: a review of experimental variables and procedures

This paper reviews literature on tactual perception. Throughout this review we will highlight some of the most relevant variables in touch literature: interaction between touch and other senses; type of stimuli, from abstract stimuli such as vibrations, to two- and three-dimensional stimuli, also considering concrete stimuli such as the relation between familiar and unfamiliar stimuli or the haptic perception of faces; type of participants, separating studies with blind participants, studies with children and adults, and an analysis of sex differences in performance; and finally, type of tactile exploration, considering conditions of active and passive touch, the relevance of movement in touch and the relation between exploration and time. This review intends to present an organised overview of the main variables in touch experiments, attending to the main findings described in literature, to guide the design of future works on tactual perception and memory.This work was funded by the Portuguese “Foundation for Science and Technology” through PhD scholarship SFRH/BD/35918/2007

Spatial representation and visual impairement - Developmental trends and new technological tools for assessment and rehabilitation

It is well known that perception is mediated by the five sensory modalities (sight, hearing, touch, smell and taste), which allows us to explore the world and build a coherent spatio-temporal representation of the surrounding environment. Typically, our brain collects and integrates coherent information from all the senses to build a reliable spatial representation of the world. In this sense, perception emerges from the individual activity of distinct sensory modalities, operating as separate modules, but rather from multisensory integration processes. The interaction occurs whenever inputs from the senses are coherent in time and space (Eimer, 2004). Therefore, spatial perception emerges from the contribution of unisensory and multisensory information, with a predominant role of visual information for space processing during the first years of life. Despite a growing body of research indicates that visual experience is essential to develop spatial abilities, to date very little is known about the mechanisms underpinning spatial development when the visual input is impoverished (low vision) or missing (blindness). The thesis's main aim is to increase knowledge about the impact of visual deprivation on spatial development and consolidation and to evaluate the effects of novel technological systems to quantitatively improve perceptual and cognitive spatial abilities in case of visual impairments. Chapter 1 summarizes the main research findings related to the role of vision and multisensory experience on spatial development. Overall, such findings indicate that visual experience facilitates the acquisition of allocentric spatial capabilities, namely perceiving space according to a perspective different from our body. Therefore, it might be stated that the sense of sight allows a more comprehensive representation of spatial information since it is based on environmental landmarks that are independent of body perspective. Chapter 2 presents original studies carried out by me as a Ph.D. student to investigate the developmental mechanisms underpinning spatial development and compare the spatial performance of individuals with affected and typical visual experience, respectively visually impaired and sighted. Overall, these studies suggest that vision facilitates the spatial representation of the environment by conveying the most reliable spatial reference, i.e., allocentric coordinates. However, when visual feedback is permanently or temporarily absent, as in the case of congenital blindness or blindfolded individuals, respectively, compensatory mechanisms might support the refinement of haptic and auditory spatial coding abilities. The studies presented in this chapter will validate novel experimental paradigms to assess the role of haptic and auditory experience on spatial representation based on external (i.e., allocentric) frames of reference. Chapter 3 describes the validation process of new technological systems based on unisensory and multisensory stimulation, designed to rehabilitate spatial capabilities in case of visual impairment. Overall, the technological validation of new devices will provide the opportunity to develop an interactive platform to rehabilitate spatial impairments following visual deprivation. Finally, Chapter 4 summarizes the findings reported in the previous Chapters, focusing the attention on the consequences of visual impairment on the developmental of unisensory and multisensory spatial experience in visually impaired children and adults compared to sighted peers. It also wants to highlight the potential role of novel experimental tools to validate the use to assess spatial competencies in response to unisensory and multisensory events and train residual sensory modalities under a multisensory rehabilitation

Perceptual Strategies and Neuronal Underpinnings underlying Pattern Recognition through Visual and Tactile Sensory Modalities in Rats

The aim of my PhD project was to investigate multisensory perception and multimodal recognition abilities in the rat, to better understand the underlying perceptual strategies and neuronal mechanisms. I have chosen to carry out this project on the laboratory rat, for two reasons. First, the rat is a flexible and highly accessible experimental model, where it is possible to combine state-of-the-art neurophysiological approaches (such as multi-electrode neuronal recordings) with behavioral investigation of perception and (more in general) cognition. Second, extensive research concerning multimodal integration has already been conducted in this species, both at the neurophysiological and behavioral level. My thesis work has been organized in two projects: a psychophysical assessment of object categorization abilities in rats, and a neurophysiological study of neuronal tuning in the primary visual cortex of anaesthetized rats. In both experiments, unisensory (visual and tactile) and multisensory (visuo-tactile) stimulation has been used for training and testing, depending on the task. The first project has required development of a new experimental rig for the study of object categorization in rat, using solid objects, so as to be able to assess their recognition abilities under different modalities: vision, touch and both together. The second project involved an electrophysiological study of rat primary visual cortex, during visual, tactile and visuo-tactile stimulation, with the aim of understanding whether any interaction between these modalities exists, in an area that is mainly deputed to one of them. The results of both of the studies are still preliminary, but they already offer some interesting insights on the defining features of these abilities

More Than a Feeling: Learning to Grasp and Regrasp using Vision and Touch

For humans, the process of grasping an object relies heavily on rich tactile feedback. Most recent robotic grasping work, however, has been based only on visual input, and thus cannot easily benefit from feedback after initiating contact. In this paper, we investigate how a robot can learn to use tactile information to iteratively and efficiently adjust its grasp. To this end, we propose an end-to-end action-conditional model that learns regrasping policies from raw visuo-tactile data. This model -- a deep, multimodal convolutional network -- predicts the outcome of a candidate grasp adjustment, and then executes a grasp by iteratively selecting the most promising actions. Our approach requires neither calibration of the tactile sensors, nor any analytical modeling of contact forces, thus reducing the engineering effort required to obtain efficient grasping policies. We train our model with data from about 6,450 grasping trials on a two-finger gripper equipped with GelSight high-resolution tactile sensors on each finger. Across extensive experiments, our approach outperforms a variety of baselines at (i) estimating grasp adjustment outcomes, (ii) selecting efficient grasp adjustments for quick grasping, and (iii) reducing the amount of force applied at the fingers, while maintaining competitive performance. Finally, we study the choices made by our model and show that it has successfully acquired useful and interpretable grasping behaviors.Comment: 8 pages. Published on IEEE Robotics and Automation Letters (RAL). Website: https://sites.google.com/view/more-than-a-feelin

How to Build an Embodiment Lab: Achieving Body Representation Illusions in Virtual Reality

Advances in computer graphics algorithms and virtual reality (VR) systems, together with the reduction in cost of associated equipment, have led scientists to consider VR as a useful tool for conducting experimental studies in fields such as neuroscience and experimental psychology. In particular virtual body ownership, where the feeling of ownership over a virtual body is elicited in the participant, has become a useful tool in the study of body representation, in cognitive neuroscience and psychology, concerned with how the brain represents the body. Although VR has been shown to be a useful tool for exploring body ownership illusions, integrating the various technologies necessary for such a system can be daunting. In this paper we discuss the technical infrastructure necessary to achieve virtual embodiment. We describe a basic VR system and how it may be used for this purpose, and then extend this system with the introduction of real-time motion capture, a simple haptics system and the integration of physiological and brain electrical activity recordings

Augmented visual, auditory, haptic, and multimodal feedback in motor learning: A review

It is generally accepted that augmented feedback, provided by a human expert or a technical display, effectively enhances motor learning. However, discussion of the way to most effectively provide augmented feedback has been controversial. Related studies have focused primarily on simple or artificial tasks enhanced by visual feedback. Recently, technical advances have made it possible also to investigate more complex, realistic motor tasks and to implement not only visual, but also auditory, haptic, or multimodal augmented feedback. The aim of this review is to address the potential of augmented unimodal and multimodal feedback in the framework of motor learning theories. The review addresses the reasons for the different impacts of feedback strategies within or between the visual, auditory, and haptic modalities and the challenges that need to be overcome to provide appropriate feedback in these modalities, either in isolation or in combination. Accordingly, the design criteria for successful visual, auditory, haptic, and multimodal feedback are elaborate

Haptic working memory: performance in interference tasks and span tasks with everyday objects

Tese de doutoramento em Psicologia Especialidade em Psicologia Experimental e Ciências CognitivasIn this work, human haptic working memory is analysed in interference and span tasks, aiming to systematically study memory for touch in natural conditions, and to examine how haptic information is encoded and processed in human memory. The first part of this thesis consists in a literature review of data on haptic perception and haptic memory. Our approach to this review implied a systematisation of the main variables manipulated in tactile and haptic studies, followed by a critical review of studies on memory for touch. The first group of experiments, evaluating the impact of interference tasks in haptic recognition is described in Part II. Participants were required to sequentially touch lists of 50 common (e.g., comb) or uncommon (e.g., plastic onion) everyday objects, either in single task or interference task conditions, and then were asked to perform an immediate incidental haptic recognition memory task, by touching a new list of 50 objects (25 presented and 25 non-presented objects) and to indicate if each object had been touched before. The interference tasks were always performed at encoding and could be haptic (evaluating paper samples), motor (performing a concurrent movement), verbal (evaluating pseudo-word pairs), or visuospatial (evaluating three-dimensional stimuli images). Results showed that participants were able to perform these tasks with a high accuracy rate, either for common or uncommon objects. For common objects, only haptic interference impaired haptic recognition. For uncommon objects, haptic recognition was affected by haptic, verbal and visual interference tasks, but not by motor interference. A final analysis, considering direct comparisons between object types for each interference condition revealed that common objects systematically present higher recognition rates, and are less affected by interference than uncommon objects. Overall, these studies suggest a haptic specificity in working memory, and an object familiarity mediation of the participant’s performance. The third part of this thesis reports a group of exploratory studies on haptic span, recurring to immediate serial recall and reconstruction of order tasks. Considering the relevance of verbal representations for everyday objects, the participant’s performance was studied in single task and articulatory suppression conditions. In immediate serial recall tasks participants were asked to touch lists of common objects (e.g., ball), starting with a list extension of two objects, and going up to ten objects, according to the participant’s performance. Results revealed an haptic span of approximately five items in single task and of four items in articulatory suppression conditions. In reconstruction of order tasks, after the list presentation, all touched objects were available again, and the participants had to order them according to the initial presentation. This task, not implying item identification (naming), allowed a comparison between common and uncommon object’s span. Results showed that similar spans exist for both conditions, with about six items being recalled in single task, and about five items in the articulatory suppression conditions. The present work is a contribute to the field of haptic cognition, specifically haptic memory, by presenting a first attempt to systematically study working memory for touch by adapting classical paradigms in the study of human memory to the haptic sensory modality. Throughout this work, empirical and theoretical topics regarding touch experiments are discussed and future research paths in this field are suggested.Neste trabalho analisa-se a memória de trabalho háptica em humanos, procurando estudá-la de forma sistemática e em condições naturais, explorando a forma como a informação háptica é codificada e processada na memória humana. A primeira parte desta tese consiste numa revisão da literatura existente nas áreas de percepção e memória táctil e háptica. A abordagem à revisão teórica passou pela sistematização das variáveis centrais nos estudos sobre tacto, seguida de uma revisão crítica do estudo da memória táctil. O primeiro grupo de experiências avalia o impacto de tarefas de interferência no reconhecimento háptico e é descrito na Parte II. Os participantes tocaram sequencialmente uma lista de 50 objectos quotidianos comuns (e.g., pente) ou incomuns (e.g., cebola de plástico), em condições de tarefa simples ou em condições de interferência. De seguida foi-lhes solicitada a realização de uma tarefa de reconhecimento háptico imediata e incidental, tocando uma nova lista de 50 objectos (25 apresentados previamente e 25 não apresentados) e indicando para cada objecto se este havia sido tocado anteriormente. A tarefa de interferência foi realizada durante a fase de codificação dos objectos e poderia ser de natureza háptica (avaliação de amostras de papel), motora (realizar um movimento específico), verbal (avaliação de pseudo-palavras), ou visuo-espacial (avaliação de imagens de estímulos tridimensionais). Os resultados demonstram que os participantes foram capazes de realizar a tarefa de reconhecimento háptico com elevadas taxas de acerto, quer para objectos comuns, quer para objectos incomuns. Para os objectos comuns, apenas a interferência háptica prejudicou o reconhecimento háptico. Para os objectos incomuns, o reconhecimento háptico foi prejudicado pela interferência háptica, verbal e visuo-espacial, mas não pela interferência motora. Uma última análise, comparando directamente o desempenho para objectos comuns e incomuns para cada tipo de interferência, revelou que os objectos comuns produzem sistematicamente melhores taxas de reconhecimento e são menos prejudicados pela interferência do que os objectos incomuns. De uma forma geral, os estudos apresentados na segunda parte deste trabalho sugerem a existência de especificidade háptica na memória de trabalho, assim como um efeito mediador da familiaridade dos estímulos no desempenho dos participantes. A terceira parte desta tese descreve um conjunto de estudos exploratórios sobre tarefas de capacidade de memória háptica, recorrendo a tarefas de evocação serial imediata e a tarefas de ordenação. Considerando a relevância das representações verbais para os objectos quotidianos, os participantes nestes estudos realizaram as tarefas de capacidade em condições de tarefa simples e com supressão articulatória Nas tarefas de evocação serial imediata, os participantes tocaram listas de objectos comuns (e.g., bola), começando a tarefa com listas com a extensão de dois objectos, que podiam ser aumentadas até um máximo de 10 objectos, dependendo do desempenho individual. Os resultados demonstram que a capacidade háptica é de aproximadamente cinco itens em condições de tarefa simples, e de quatro itens em condições de supressão articulatória. Nas tarefas de ordenação, após a apresentação das listas, todos os objectos tocados estão disponíveis para o participante, que deverá ordená-los de acordo com a apresentação inicial. Nesta tarefa, uma vez que não é necessária a identificação dos itens, foi possível comparar o desempenho com objectos comuns e incomuns. Os resultados mostram que o número de itens correctamente ordenados é idêntico para objectos comuns e incomuns e corresponde a aproximadamente seis itens em condições de tarefa simples e a cinco itens em condições de supressão articulatória. Este trabalho apresenta-se como um contributo para o campo da cognição háptica, especificamente da memória háptica, apresentando uma primeira tentativa de estudar sistematicamente a memória para o tacto, adaptando paradigmas clássicos no estudo da memória humana à modalidade sensorial háptica. Ao longo deste trabalho, tópicos empíricos e teóricos acerca das experiências com tacto serão discutidos e serão sugeridos caminhos de investigação futura nesta área

Visuo-Haptic Exploration for Multimodal Memory

When faced with a novel object, we explore it to understand its shape. This way we combine information coming from different senses, as touch, proprioception and vision, together with the motor information embedded in our motor execution plan. The exploration process provides a structure and constrains this rich flow of inputs, supporting the formation of a unified percept and the memorization of the object features. However, how the exploration strategies are planned is still an open question. In particular, is the exploration strategy used to memorize an object different from the exploration strategy adopted in a recall task? To address this question we used iCube, a sensorized cube which measures its orientation in space and the location of the contacts on its faces. Participants were required to explore the cube faces where little pins were positioned in varying number. Participants had to explore the cube twice and individuate potential differences between the two presentations, which could be performed either haptically alone, or with also vision available. The haptic and visuo-haptic (VH) exploratory strategies changed significantly when finalized to memorize the structure of the object with respect to when the same object was explored to recall and compare it with its memorized instance. These findings indicate that exploratory strategies are adapted not only to the property of the object to be analyzed but also to the prospective use of the resulting representation, be it memorization or recall. The results are discussed in light of the possibility of a systematic modeling of natural VH exploration strategies

Multisensory Perception and Learning: Linking Pedagogy, Psychophysics, and Human–Computer Interaction

In this review, we discuss how specific sensory channels can mediate the learning of properties of the environment. In recent years, schools have increasingly been using multisensory technology for teaching. However, it still needs to be sufficiently grounded in neuroscientific and pedagogical evidence. Researchers have recently renewed understanding around the role of communication between sensory modalities during development. In the current review, we outline four principles that will aid technological development based on theoretical models of multisensory development and embodiment to foster in-depth, perceptual, and conceptual learning of mathematics. We also discuss how a multidisciplinary approach offers a unique contribution to development of new practical solutions for learning in school. Scientists, engineers, and pedagogical experts offer their interdisciplinary points of view on this topic. At the end of the review, we present our results, showing that one can use multiple sensory inputs and sensorimotor associations in multisensory technology to improve the discrimination of angles, but also possibly for educational purposes. Finally, we present an application, the ‘RobotAngle’ developed for primary (i.e., elementary) school children, which uses sounds and body movements to learn about angles