75 research outputs found

    Event-related alpha suppression in response to facial motion

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    This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

    Dynamic Visuomotor Transformation Involved with Remote Flying of a Plane Utilizes the ‘Mirror Neuron’ System

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    Brain regions involved with processing dynamic visuomotor representational transformation are investigated using fMRI. The perceptual-motor task involved flying (or observing) a plane through a simulated Red Bull Air Race course in first person and third person chase perspective. The third person perspective is akin to remote operation of a vehicle. The ability for humans to remotely operate vehicles likely has its roots in neural processes related to imitation in which visuomotor transformation is necessary to interpret the action goals in an egocentric manner suitable for execution. In this experiment for 3rd person perspective the visuomotor transformation is dynamically changing in accordance to the orientation of the plane. It was predicted that 3rd person remote flying, over 1st, would utilize brain regions composing the ‘Mirror Neuron’ system that is thought to be intimately involved with imitation for both execution and observation tasks. Consistent with this prediction differential brain activity was present for 3rd person over 1st person perspectives for both execution and observation tasks in left ventral premotor cortex, right dorsal premotor cortex, and inferior parietal lobule bilaterally (Mirror Neuron System) (Behaviorally: 1st>3rd). These regions additionally showed greater activity for flying (execution) over watching (observation) conditions. Even though visual and motor aspects of the tasks were controlled for, differential activity was also found in brain regions involved with tool use, motion perception, and body perspective including left cerebellum, temporo-occipital regions, lateral occipital cortex, medial temporal region, and extrastriate body area. This experiment successfully demonstrates that a complex perceptual motor real-world task can be utilized to investigate visuomotor processing. This approach (Aviation Cerebral Experimental Sciences ACES) focusing on direct application to lab and field is in contrast to standard methodology in which tasks and conditions are reduced to their simplest forms that are remote from daily life experience

    Post-doctoral research fellowship as a health policy and systems research capacity development intervention: a case of the CHESAI initiative

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    BACKGROUND: Building capacity in health policy and systems research (HPSR), especially in low- and middle-income countries, remains a challenge. Various approaches have been suggested and implemented by scholars and institutions using various forms of capacity building to address challenges regarding HPSR development. The Collaboration for Health Systems Analysis and Innovation (CHESAI) – a collaborative effort between the Universities of Cape Town and the Western Cape Schools of Public Health – has employed a non-research based post-doctoral research fellowship (PDRF) as a way of building African capacity in the field of HPSR by recruiting four post-docs. In this paper, we (the four post-docs) explore whether a PDRF is a useful approach for capacity building for the field of HPSR using our CHESAI PDRF experiences. METHODS: We used personal reflections of our written narratives providing detailed information regarding our engagement with CHESAI. The narratives were based on a question guide around our experiences through various activities and their impacts on our professional development. The data analysis process was highly iterative in nature, involving repeated meetings among the four post-docs to reflect, discuss and create themes that evolved from the discussions. RESULTS: The CHESAI PDRF provided multiple spaces for our engagement and capacity development in the field of HPSR. These spaces provided us with a wide range of learning experiences, including teaching and research, policy networking, skills for academic writing, engaging practitioners, co-production and community dialogue. Our reflections suggest that institutions providing PDRF such as this are valuable if they provide environments endowed with adequate resources, good leadership and spaces for innovation. Further, the PDRFs need to be grounded in a community of HPSR practice, and provide opportunities for the post-docs to gain an in-depth understanding of the broader theoretical and methodological underpinnings of the field. CONCLUSION: The study concludes that PDRF is a useful approach to capacity building in HPSR, but it needs be embedded in a community of practice for fellows to benefit. More academic institutions in Africa need to adopt innovative and flexible support for emerging leaders, researchers and practitioners to strengthen our health systemsIS

    Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty

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    This study explores how researchers’ analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers’ expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team’s workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers’ results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings

    The Crowdsourced Replication Initiative: Investigating Immigration and Social Policy Preferences. Executive Report.

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    In an era of mass migration, social scientists, populist parties and social movements raise concerns over the future of immigration-destination societies. What impacts does this have on policy and social solidarity? Comparative cross-national research, relying mostly on secondary data, has findings in different directions. There is a threat of selective model reporting and lack of replicability. The heterogeneity of countries obscures attempts to clearly define data-generating models. P-hacking and HARKing lurk among standard research practices in this area.This project employs crowdsourcing to address these issues. It draws on replication, deliberation, meta-analysis and harnessing the power of many minds at once. The Crowdsourced Replication Initiative carries two main goals, (a) to better investigate the linkage between immigration and social policy preferences across countries, and (b) to develop crowdsourcing as a social science method. The Executive Report provides short reviews of the area of social policy preferences and immigration, and the methods and impetus behind crowdsourcing plus a description of the entire project. Three main areas of findings will appear in three papers, that are registered as PAPs or in process

    Restoring macrophyte diversity in shallow temperate lakes: biotic versus abiotic constraints

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