Moving from stroke to development : a deconstruction of skilled reaching in humans

xiii, 254 leaves : ill. (some col.) ; 29 cmThe purpose of this thesis is to describe the organization of the movements of skilled reaching. Our knowledge of reaching behaviour has been limited to an understanding of specific actions. Results from this thesis describe how reaching is the product of interactions of various parameters that assemble in an integrative way in ontogeny, yet can become dismantled on one level, or generally, throughout multiple levels of what constitutes the behaviour after stroke in adults. These findings demonstrate that skilled reaching constitutes motor parameters that may not be visible in a healthy adult, but that function through development, and by inhibitory systems in adults, to create a smooth and finely articulated action. An examination of the movement patterns of reaching within the full context of the behaviour can be applied to therapeutic strategies for motor disorders and, most importantly, deepen our understanding of the relations between reaching and cognition

Effects of a Multitouch Keyboard on Wrist Posture, Typing Performance and Comfort

Alan Hedge Geri GayThe design of computer keyboards is rapidly evolving as portable computing becomes increasingly ubiquitous due to wireless networking and the increased popularity of personal digital assistants and notebook computers. However, there is a balance between mobility and productivity, in terms of text-entry accuracy and speed, which needs to be maintained as computer keyboards become smaller and slimmer through the introduction of ultra low-profile designs. In addition, the ergonomic benefits, in terms of the reduction of awkward wrist postures and user comfort, of ultra-low profile designs are unclear. This study tests a new prototype ultra-low profile MultiTouch keyless keyboard (MTK) that uses a MultiTouch surface to create an extremely thin typing environment that requires no force to register a keystroke and allows mousing and gestural input on the same surface. In this study, the MTK was tested against a conventional keyboard (CK) for typing speed, accuracy, wrist postures and user comfort. It was hypothesized that the lack of key travel would increase speed and accuracy, while the ultra-thin design would reduce the amount of wrist extension, which could decrease the risk of a wrist injury or other hand and wrist musculoskeletal disorder. Finally, it was hypothesized that there would be a significant short-term learning effect on typing speed and accuracy for the MTK. A laboratory experiment was conducted with 6 males and 6 females typing using two QWERTY keyboard designs: a CK and a MTK. Subjects visited the lab for 1.5 hours for 2 non-consecutive days in the same week, for a total of 3 hours. Each visit consisted of eight randomly assigned 7.5-minute typing tasks of text passages of similar difficulty and identical length. Quantitative measures of typing speed and accuracy were collected using Typing Quick and Easy 13.0 and qualitative measures of user preference and comfort were gathered by self-report questionnaires. A wrist glove electrogoniometer system was used to record right-hand wrist positioning data, which was analyzed to assess the risk of injury. The two keyboards were evaluated in a repeated measures within-subjects factorial design. Subjects, typed slower (F1,11 = 41.86, p=0.000) and less accurately (F1,11 = 23.55, p=0.001) on the MTK during the typing tasks. Subjects preferred the CK and reported a higher level of ease (F1,11 = 49.732, p=0.00) and enjoyment (F1,11 = 51.129, p=0.00) during its use. Mean wrist extension was lower for the MTK (F1,11= 10.205, p=0.000) while radial and ulnar deviation did not differ significantly between the two keyboards. The MTK had a lower percentage of highest-risk wrist extension (F1,11= 6.437, p=0.028), and conversely, a higher percentage of neutral wrist posture (F1,11= 12.947, p=0.004). A significant positive linear trend was observed across the within-subjects scores for speed (F1,11= 9.308, p=0.011) and accuracy (F1,11= 11.903, p=0.005) across tasks in the MTK condition. Limitations to this study include practice effects, due to the naive subjects' lack of training on the MTK and the limited duration of exposure to this novel keyboard. Fatigue effects may have also been a factor, even though the experimental conditions were spread out over two non-consecutive days in the same week. Future research directions include additional testing of the unique mousing and gestural capabilities of the MTK. Other research suggests that practice and extended exposure to the MTK may raise performance to comparable levels associated with CK devices.College of Human Ecology, Cornell Universit

Multisensory learning in adaptive interactive systems

The main purpose of my work is to investigate multisensory perceptual learning and sensory integration in the design and development of adaptive user interfaces for educational purposes. To this aim, starting from renewed understanding from neuroscience and cognitive science on multisensory perceptual learning and sensory integration, I developed a theoretical computational model for designing multimodal learning technologies that take into account these results. Main theoretical foundations of my research are multisensory perceptual learning theories and the research on sensory processing and integration, embodied cognition theories, computational models of non-verbal and emotion communication in full-body movement, and human-computer interaction models. Finally, a computational model was applied in two case studies, based on two EU ICT-H2020 Projects, "weDRAW" and "TELMI", on which I worked during the PhD

The Perception/Action loop: A Study on the Bandwidth of Human Perception and on Natural Human Computer Interaction for Immersive Virtual Reality Applications

Virtual Reality (VR) is an innovating technology which, in the last decade, has had a widespread success, mainly thanks to the release of low cost devices, which have contributed to the diversification of its domains of application. In particular, the current work mainly focuses on the general mechanisms underling perception/action loop in VR, in order to improve the design and implementation of applications for training and simulation in immersive VR, especially in the context of Industry 4.0 and the medical field. On the one hand, we want to understand how humans gather and process all the information presented in a virtual environment, through the evaluation of the visual system bandwidth. On the other hand, since interface has to be a sort of transparent layer allowing trainees to accomplish a task without directing any cognitive effort on the interaction itself, we compare two state of the art solutions for selection and manipulation tasks, a touchful one, the HTC Vive controllers, and a touchless vision-based one, the Leap Motion. To this aim we have developed ad hoc frameworks and methodologies. The software frameworks consist in the creation of VR scenarios, where the experimenter can choose the modality of interaction and the headset to be used and set experimental parameters, guaranteeing experiments repeatability and controlled conditions. The methodology includes the evaluation of performance, user experience and preferences, considering both quantitative and qualitative metrics derived from the collection and the analysis of heterogeneous data, as physiological and inertial sensors measurements, timing and self-assessment questionnaires. In general, VR has been found to be a powerful tool able to simulate specific situations in a realistic and involving way, eliciting user\u2019s sense of presence, without causing severe cybersickness, at least when interaction is limited to the peripersonal and near-action space. Moreover, when designing a VR application, it is possible to manipulate its features in order to trigger or avoid triggering specific emotions and voluntarily create potentially stressful or relaxing situations. Considering the ability of trainees to perceive and process information presented in an immersive virtual environment, results show that, when people are given enough time to build a gist of the scene, they are able to recognize a change with 0.75 accuracy when up to 8 elements are in the scene. For interaction, instead, when selection and manipulation tasks do not require fine movements, controllers and Leap Motion ensure comparable performance; whereas, when tasks are complex, the first solution turns out to be more stable and efficient, also because visual and audio feedback, provided as a substitute of the haptic one, does not substantially contribute to improve performance in the touchless case

Simulating Humans: Computer Graphics, Animation, and Control

People are all around us. They inhabit our home, workplace, entertainment, and environment. Their presence and actions are noted or ignored, enjoyed or disdained, analyzed or prescribed. The very ubiquitousness of other people in our lives poses a tantalizing challenge to the computational modeler: people are at once the most common object of interest and yet the most structurally complex. Their everyday movements are amazingly uid yet demanding to reproduce, with actions driven not just mechanically by muscles and bones but also cognitively by beliefs and intentions. Our motor systems manage to learn how to make us move without leaving us the burden or pleasure of knowing how we did it. Likewise we learn how to describe the actions and behaviors of others without consciously struggling with the processes of perception, recognition, and language

Haptics: Science, Technology, Applications

This open access book constitutes the proceedings of the 12th International Conference on Human Haptic Sensing and Touch Enabled Computer Applications, EuroHaptics 2020, held in Leiden, The Netherlands, in September 2020. The 60 papers presented in this volume were carefully reviewed and selected from 111 submissions. The were organized in topical sections on haptic science, haptic technology, and haptic applications. This year's focus is on accessibility

Imagining & Sensing: Understanding and Extending the Vocalist-Voice Relationship Through Biosignal Feedback

The voice is body and instrument. Third-person interpretation of the voice by listeners, vocal teachers, and digital agents is centred largely around audio feedback. For a vocalist, physical feedback from within the body provides an additional interaction. The vocalist’s understanding of their multi-sensory experiences is through tacit knowledge of the body. This knowledge is difficult to articulate, yet awareness and control of the body are innate. In the ever-increasing emergence of technology which quantifies or interprets physiological processes, we must remain conscious also of embodiment and human perception of these processes. Focusing on the vocalist-voice relationship, this thesis expands knowledge of human interaction and how technology influences our perception of our bodies. To unite these different perspectives in the vocal context, I draw on mixed methods from cog- nitive science, psychology, music information retrieval, and interactive system design. Objective methods such as vocal audio analysis provide a third-person observation. Subjective practices such as micro-phenomenology capture the experiential, first-person perspectives of the vocalists them- selves. Quantitative-qualitative blend provides details not only on novel interaction, but also an understanding of how technology influences existing understanding of the body. I worked with vocalists to understand how they use their voice through abstract representations, use mental imagery to adapt to altered auditory feedback, and teach fundamental practice to others. Vocalists use multi-modal imagery, for instance understanding physical sensations through auditory sensations. The understanding of the voice exists in a pre-linguistic representation which draws on embodied knowledge and lived experience from outside contexts. I developed a novel vocal interaction method which uses measurement of laryngeal muscular activations through surface electromyography. Biofeedback was presented to vocalists through soni- fication. Acting as an indicator of vocal activity for both conscious and unconscious gestures, this feedback allowed vocalists to explore their movement through sound. This formed new perceptions but also questioned existing understanding of the body. The thesis also uncovers ways in which vocalists are in control and controlled by, work with and against their bodies, and feel as a single entity at times and totally separate entities at others. I conclude this thesis by demonstrating a nuanced account of human interaction and perception of the body through vocal practice, as an example of how technological intervention enables exploration and influence over embodied understanding. This further highlights the need for understanding of the human experience in embodied interaction, rather than solely on digital interpretation, when introducing technology into these relationships