232 research outputs found

    When gestures show us the way: Co-speech gestures selectively facilitate navigation and spatial memory.

    Get PDF
    How does gesturing during route learning relate to subsequent spatial performance? We examined the relationship between gestures produced spontaneously while studying route directions and spatial representations of the navigated environment. Participants studied route directions, then navigated those routes from memory in a virtual environment, and finally had their memory of the environment assessed. We found that, for navigators with low spatial perspective-taking performance on the Spatial Orientation Test, more gesturing from a survey perspective predicted more accurate memory following navigation. Thus, co-thought gestures accompanying route learning relate to performance selectively, depending on the gesturers’ spatial ability and the perspective of their gestures. Survey gestures may help some individuals visualize an overall route that they can retain in memory

    The conversational partner's perspective affects spatial memory and descriptions.

    Get PDF
    We examined whether people spontaneously represent the partner’s viewpoint in spatial memory when it is available in advance and whether they adapt their spontaneous descriptions accordingly. In 18 pairs, Directors studied arrays of objects while: (1) not knowing about having to describe the array to a Matcher, (2) knowing about the subsequent description, and (3) knowing the Matcher’s subsequent viewpoint, which was offset by 90, 135, or 180. In memory tests preceding descriptions, Directors represented the Matcher’s viewpoint when it was known during study, taking longer to imagine orienting to perspectives aligned with it and rotating their drawings of arrays toward it. Conversely, when Directors didn’t know their Matcher’s viewpoint, they encoded arrays egocentrically, being faster to imagine orienting to and to respond from perspectives aligned with their own. Directors adapted their descriptions flexibly, using partner-centered spatial expressions more frequently when misaligned by 90 and egocentric ones when misaligned by 135. Knowing their misalignment in advance helped partners recognize when descriptions would be most difficult for Directors (at 135) and to mutually agree on using their perspective. Thus, in collaborative tasks, people don’t rely exclusively on their spatial memory but also use other pertinent perceptual information (e.g., their misalignment from their partner) to assess the computational demands on each partner and select strategies that maximize the efficiency of communication

    The effect of cognition on the visually-induced illusion of self-motion (vection)

    No full text
    INTRODUCTION: The illusion of self-motion induced by moving visual stimuli has typically been attributed to bottom-up perceptual processes. Here, we investigated whether a cognitive factor such as spatial presence can contribute to the illusion. Spatial presence was indirectly manipulated by presenting either a photorealistic image of a natural scene or modified versions of the same stimulus. Those were created by either scrambling image parts in a mosaic-like manner or by slicing the original image horizontally and randomly reassembling it. We expected scene modifications to decrease spatial presence and thus impair vection. METHODS: Twelve observers viewed stimuli projected onto a curved projection screen (FOV: 54 ×40.5 ). Dependent measures included vection onset time, vection intensity, and convincingness of the illusion (0–100 ratings). Spatial presence was assessed with presence questionnaires. RESULTS: Scene modification led to both reduced presence scores and impaired vection: Modified stimuli yielded significantly longer vection onset times, lower perceived intensity, and lower convincingness ratings than the intact market scene. No clear difference was found between the sliced and scrambled stimuli or among the number of slices or mosaics (2, 8, or 32). Results suggest that high level information (consistent reference frame for the intact market scene) dominated over the low-level information (more contrast edges in the scrambled stimulus, which are known to facilitate vection). CONCLUSIONS: Results suggest a direct relation between spatial presence and self-motion perception. We posit that stimuli depicting naturalistic scenes provide observers with a convincing reference frame for the simulated environment which enables them to feel “spatially present”. This, in turn, facilitates the self-motion illusion. This work has important implications for both self-motion perception and motion simulator design and applications

    Diffuse precordial ST-segment elevation in inferior-right myocardial infarction

    Get PDF
    A right ventricular (RV) myocardial infarction (MI) may yield precordial ST-segment elevation (STE). Accordingly, combined inferior and precordial STE may be produced during an inferior-RV MI. Such an electrocardiographic picture may be mistakenly regarded as showing wrapped left anterior descending artery (LADA) occlusion or double vessel occlusion. We present a patient with inferior-RV MI and STE in the inferior, all precordial and right chest leads, in whom the diffuse precordial STE was probably mistakenly regarded as showing anterior MI. However, the STE resolution in V1-V2 and late R’ wave in V1, which were combined with a recanalized RV branch, favored the RV origin of this STE. Furthermore, the LADA was patent when V3-V6 showed severe ischemia, while its lesion was angiographically stable. Thus its simultaneous occlusion was unlikely. The late R’ wave in V1 indicates RV transmural conduction delay;as highlighted herein, it is diagnostic of a RV myocardial infarction. (Cardiol J 2010; 17, 6: 628-631

    Spatial updating in narratives.

    Get PDF
    Across two experiments we investigated spatial updating in environments encoded through narratives. In Experiment 1, in which participants were given visualization instructions to imagine the protagonist’s movement, they formed an initial representation during learning but did not update it during subsequent described movement. In Experiment 2, in which participants were instructed to physically move in space towards the directions of the described objects prior to testing, there was evidence for spatial updating. Overall, findings indicate that physical movement can cause participants to link a spatial representation of a remote environment to a sensorimotor framework and update the locations of remote objects while they move

    Integrins as therapeutic targets: lessons and opportunities.

    Get PDF
    The integrins are a large family of cell adhesion molecules that are essential for the regulation of cell growth and function. The identification of key roles for integrins in a diverse range of diseases, including cancer, infection, thrombosis and autoimmune disorders, has revealed their substantial potential as therapeutic targets. However, so far, pharmacological inhibitors for only three integrins have received marketing approval. This article discusses the structure and function of integrins, their roles in disease and the chequered history of the approved integrin antagonists. Recent advances in the understanding of integrin function, ligand interaction and signalling pathways suggest novel strategies for inhibiting integrin function that could help harness their full potential as therapeutic targets

    Sensorimotor alignment effects in the learning environment and in novel environments.

    Full text link
    Four experiments investigated the conditions contributing to sensorimotor alignment effects (i.e., the advantage for spatial judgments from imagined perspectives aligned with the body). Through virtual reality technology, participants learned object locations around a room (learning room) and made spatial judgments from imagined perspectives aligned or misaligned with their actual facing direction. Senso-rimotor alignment effects were found when testing occurred in the learning room but not after walking 3 m into a neighboring (novel) room. Sensorimotor alignment effects returned after returning to the learning room or after providing participants with egocentric imagery instructions in the novel room. Additionally, visual and spatial similarities between the test and learning environments were indepen-dently sufficient to cause sensorimotor alignment effects. Memory alignment effects, independent from sensorimotor alignment effects, occurred in all testing conditions. Results are interpreted in the context of two-system spatial memory theories positing separate representations to account for sensorimotor and memory alignment effects

    A combinatorial extracellular matrix platform identifies cell-extracellular matrix interactions that correlate with metastasis

    Get PDF
    Extracellular matrix interactions have essential roles in normal physiology and many pathological processes. Although the importance of extracellular matrix interactions in metastasis is well documented, systematic approaches to identify their roles in distinct stages of tumorigenesis have not been described. Here we report a novel-screening platform capable of measuring phenotypic responses to combinations of extracellular matrix molecules. Using a genetic mouse model of lung adenocarcinoma, we measure the extracellular matrix-dependent adhesion of tumour-derived cells. Hierarchical clustering of the adhesion profiles differentiates metastatic cell lines from primary tumour lines. Furthermore, we uncovered that metastatic cells selectively associate with fibronectin when in combination with galectin-3, galectin-8 or laminin. We show that these molecules correlate with human disease and that their interactions are mediated in part by α3β1 integrin. Thus, our platform allowed us to interrogate interactions between metastatic cells and their microenvironments, and identified extracellular matrix and integrin interactions that could serve as therapeutic targets.National Institutes of Health (U.S.) (Grant K99-CA151968)National Institutes of Health (U.S.). Ruth L. Kirschstein National Research Service AwardStand Up To Cancer (SU2C/AACR)David H. Koch Institute for Integrative Cancer Research at MIT (CTC Project)Harvard Stem Cell Institute (SG-0046-08-00)National Cancer Center (Postdoctoral Fellowship)National Cancer Institute (U.S.) (U54CA126515)National Cancer Institute (U.S.) (U54CA112967)Howard Hughes Medical InstituteMassachusetts Institute of Technology. Ludwig Center for Molecular Oncolog
    corecore