4,066 research outputs found

    Causative role of left aIPS in coding shared goals during human-avatar complementary joint actions

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    Successful motor interactions require agents to anticipate what a partner is doing in order to predictively adjust their own movements. Although the neural underpinnings of the ability to predict others' action goals have been well explored during passive action observation, no study has yet clarified any critical neural substrate supporting interpersonal coordination during active, non-imitative (complementary) interactions. Here, we combine non-invasive inhibitory brain stimulation (continuous Theta Burst Stimulation) with a novel human-avatar interaction task to investigate a causal role for higher-order motor cortical regions in supporting the ability to predict and adapt to others' actions. We demonstrate that inhibition of left anterior intraparietal sulcus (aIPS), but not ventral premotor cortex, selectively impaired individuals' performance during complementary interactions. Thus, in addition to coding observed and executed action goals, aIPS is crucial in coding 'shared goals', that is, integrating predictions about one's and others' complementary actions

    Gender differences in spatial ability within virtual reality

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    EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Wayfinding across ocean and tundra: what traditional cultures teach us about navigation

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    Research on human navigation by psychologists and neuroscientists has come mainly from a limited range of environments and participants inhabiting western countries. By contrast, numerous anthropological accounts illustrate the diverse ways in which cultures adapt to their surrounding environment to navigate. Here, we provide an overview of these studies and relate them to cognitive science research. The diversity of cues in traditional navigation is much higher and multimodal compared with navigation experiments in the laboratory. It typically involves an integrated system of methods, drawing on a detailed understanding of the environmental cues, specific tools, and forms part of a broader cultural system. We highlight recent methodological developments for measuring navigation skill and modelling behaviour that will aid future research into how culture and environment shape human navigation

    Hybrid approaches for mobile robot navigation

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    The work described in this thesis contributes to the efficient solution of mobile robot navigation problems. A series of new evolutionary approaches is presented. Two novel evolutionary planners have been developed that reduce the computational overhead in generating plans of mobile robot movements. In comparison with the best-performing evolutionary scheme reported in the literature, the first of the planners significantly reduces the plan calculation time in static environments. The second planner was able to generate avoidance strategies in response to unexpected events arising from the presence of moving obstacles. To overcome limitations in responsiveness and the unrealistic assumptions regarding a priori knowledge that are inherent in planner-based and a vigation systems, subsequent work concentrated on hybrid approaches. These included a reactive component to identify rapidly and autonomously environmental features that were represented by a small number of critical waypoints. Not only is memory usage dramatically reduced by such a simplified representation, but also the calculation time to determine new plans is significantly reduced. Further significant enhancements of this work were firstly, dynamic avoidance to limit the likelihood of potential collisions with moving obstacles and secondly, exploration to identify statistically the dynamic characteristics of the environment. Finally, by retaining more extensive environmental knowledge gained during previous navigation activities, the capability of the hybrid navigation system was enhanced to allow planning to be performed for any start point and goal point

    Biosignals reflect pair-dynamics in collaborative work : EDA and ECG study of pair-programming in a classroom environment

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    Collaboration is a complex phenomenon, where intersubjective dynamics can greatly affect the productive outcome. Evaluation of collaboration is thus of great interest, and can potentially help achieve better outcomes and performance. However, quantitative measurement of collaboration is difficult, because much of the interaction occurs in the intersubjective space between collaborators. Manual observation and/or self-reports are subjective, laborious, and have a poor temporal resolution. The problem is compounded in natural settings where task-activity and response-compliance cannot be controlled. Physiological signals provide an objective mean to quantify intersubjective rapport (as synchrony), but require novel methods to support broad deployment outside the lab. We studied 28 student dyads during a self-directed classroom pair-programming exercise. Sympathetic and parasympathetic nervous system activation was measured during task performance using electrodermal activity and electrocardiography. Results suggest that (a) we can isolate cognitive processes (mental workload) from confounding environmental effects, and (b) electrodermal signals show role-specific but correlated affective response profiles. We demonstrate the potential for social physiological compliance to quantify pair-work in natural settings, with no experimental manipulation of participants required. Our objective approach has a high temporal resolution, is scalable, non-intrusive, and robust.Peer reviewe

    Aerospace medicine and biology. A continuing bibliography with indexes, supplement 206, May 1980

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    This bibliography lists 169 reports, articles, and other documents introduced into the NASA scientific and technical information system in April 1980

    From Nunavut to Micronesia: feedback and description, visual repatriation and online photographs of indigenous peoples

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    David A. Smith is the Indigenous Studies Librarian, University of SaskatchewanTwo pioneering web projects, Project Naming, created by Library and Archives Canada and the Inuit, and the Traditional Micronesian Navigation Collection at the University of Hawaii Library are examined. These sites make direct use of the internet to improve descriptions of their photographic holdings related to Indigenous peoples and to share these images with remote communities and the world. Through the creation of a system of " visual repatriation" and "feedback" and description, the people of Nunavut and the atoll of Satawal (in Micronesia) have the opportunity to view and identify photos of their ancestors, relatives and themselves online while at the same time sharing their knowledge with each host institution to improve descriptions of its holdings. The author concludes that, while challenges remain, these innovative approaches have helped foster meaningful relationships between, and rewards for, the participating host institutions and Indigenous peoples. In addition it is argued that the two projects bode well for: future collaborative efforts between libraries/archives and remote user-groups, understanding of our holdings, and the quality of our services to researcher

    Studying Control Processes for Bridge Teams

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    Several technological advances have been seen the maritime domain to achieve higher operational efficiency and to address the generally recognised causes of most maritime accidents. The International Maritime Organization (IMO) endorses the use of best available technology to “drive continuous improvement and innovation in the facilitation of maritime traffic” in line with the goal of sustainable development. It is commonly acknowledged that modern technology revolutionized marine navigation, and presently it has a large potential to increase safety in navigation. However, the incorporation of new technologies in support of navigation also brought unforeseen critical consequences, contributing to unsafe practices, or even to accidents or incidents. Several issues were associated with human factors. To properly address the adoption of the newest technology in support of safe navigation, IMO established the e-navigation concept, currently under implementation. The complexity of the maritime socio-technical system requires novel theoretical foundations, since many of the present framework rely on the analysis of accidents. The design of complex maritime navigation system must take place on several levels, providing different perspectives over the system problems. The evaluation and design of technologies envisaged by the e-navigation concept requires a better understand of how teams perform the navigation work in the pursuit of safe navigation. This study attempts to provide a better understanding on how maritime navigation is currently done on-board, considering the overarching elements and their interactions. In maritime navigation safety is a transverse issue, and that is why we need to know the conditions for safe navigation to improve the design of ship navigation control. The work supporting this thesis was focused on: (i) understanding how navigation is done and to perceive by the practitioners, (ii) understanding interactions between humans and technological interfaces, and (iii) understanding the relevant soft skills for the navigation functions. To address these topics, data was collected from expert practitioners such as navigators, pilots and instructors, thru semi structured interviews and questionnaires. The mains contribution of this study lies in presenting a framework of maritime navigation, exploring the control processes in the different levels of the maritime socio-technical system. In the view of safe operations, interactions between stakeholders are clarified, trying to determine how they influence safe navigation. This systemic view is then analysed from the perspective of the ship, considering it as a Joint-cognitive system (JCS). It is proposed that this JCS comprises 5 control levels: reactive, proactive, planning, strategic and political-economical. Planning is considered a fundamental process in the maritime Socio-technical system, because it facilitates the interactions between the different control level. It also increases the integrity of communications and enhances the predictability of the different control agents. New directions are proposed to improve the design of navigation system, recommending new roles for human and automated agents, and presenting a new conceptual navigation display.info:eu-repo/semantics/publishedVersio

    The neurophysiological changes associated with motor learning in adults and adolescents

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    One main purpose of this dissertation was to explore how sensorimotor cortical oscillations changed after practicing a novel ankle plantarflexion target matching task. We behaviorally quantified the speed, accuracy, reaction time, velocity, and variability of the participant’s performance of the task, while collecting their neurophysiological responses with magnetoencephalography (MEG). With these data, we assessed how the motor planning and execution stages of movement during a goal directed target matching task changed after practicing a task in typically developing young adults with their non-dominant ankle. We found that the cortical oscillations in the beta frequency range that were sourced from the sensorimotor and occipital cortices were weaker after practice. These individuals also improved behaviorally, with faster speed, greater accuracy, higher velocity, and less variability. The decreased strength likely reflects a more refined motor plan, a reduction in neural resources needed to perform the task, and/or an enhancement of the processes that are involved in the visuomotor transformations that occur prior to the onset of the motor action. The second purpose was to explore how the changes of the sensorimotor cortical oscillations after practicing a novel ankle plantarflexion target matching task differ between adults and adolescents. We assessed these behavioral and neurophysiological changes in a cohort of typically developed adults and adolescents. After practice, all of the participants matched more targets, matched the targets faster, had improved accuracy, faster reaction times, and faster force production. However, the motor performance of the adults exceeded what was seen in the adolescents regardless of practice. In conjunction with the behavioral results, the strength of the beta ERD across the motor planning and execution stages was reduced after practice in the sensorimotor cortices of the adolescents, but was stronger in the adults. These outcomes suggest that there are age-dependent changes in the sensorimotor cortical oscillations after practice, which might be related to familiarity with the motor task. The third purpose was to explore how movement attenuates the somatosensory cortical oscillations and how this attenuation differs in adults and adolescents. We used MEG to address this knowledge gap by applying an electrical stimulation to the tibial nerve as adolescents and adults produced an isometric ankle plantarflexion force, or sat quietly with no motor activity. We found movement-related attenuation of the somatosensory oscillations. Attenuation of the alpha-beta ERS while producing the isometric force was greater in adolescents when compared with adults, while the adults had a greater attenuation of the beta ERD. These results imply that alterations of frequency specific somatosensory cortical oscillations may partly underlie the altered motor performance characteristics seen in adolescents

    To the North Coast of Devon: Collaborative Navigation While Exploring Unfamiliar Terrain

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    Navigation-knowing where one is and finding a safe route-is a fundamental aspect of all exploration. In unfamiliar terrain, one may use maps and instruments such as a compass or binoculars to assist, and people often collaborate in finding their way. This paper analyzes a group of people driving a humvee from a base camp to the north coast of Devon Island in the High Canadian Arctic. A complete audio recording and video during most stops allows a quantitative and semantic analysis of the conversations when the team stopped to take bearings and replan a route. Over a period of 2 hours, the humvee stopped 20 times, with an average duration of 3.15 min/pause and 3.85 min moving forward. The team failed to reach its goal due to difficult terrain causing mechanical problems. The analysis attempts to explain these facts by considering a variety of complicating factors, especially the navigation problem of relating maps and the world to locate the humvee and to plan a route. The analysis reveals patterns in topic structure and turn-taking, supporting the view that the collaboration was efficient, but the tools and information were inadequate for the task. This work is relevant for planning and training for planetary surface missions, as well as developing computer systems that could aid navigation
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