2,925 research outputs found

    Social Evaluation of Faces Across Gender and Familiarity

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    Models of social evaluation aim to capture the information people use to form first impressions of unfamiliar others. However, little is currently known about the relationship between perceived traits across gender. In Study 1, we asked viewers to provide ratings of key social dimensions (dominance, trustworthiness, etc.) for multiple images of 40 unfamiliar identities. We observed clear sex differences in the perception of dominance—with negative evaluations of high dominance in unfamiliar females but not males. In Study 2, we used the social evaluation context to investigate the key predictions about the importance of pictorial information in familiar and unfamiliar face processing. We compared the consistency of ratings attributed to different images of the same identities and demonstrated that ratings of images depicting the same familiar identity are more tightly clustered than those of unfamiliar identities. Such results imply a shift from image rating to person rating with increased familiarity, a finding which generalises results previously observed in studies of identification. </jats:p

    Event-related potentials reveal the development of stable face representations from natural variability

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    Natural variability between instances of unfamiliar faces can make it difficult to reconcile two images as the same person. Yet for familiar faces, effortless recognition occurs even with considerable variability between images. To explore how stable face representations develop, we employed incidental learning in the form of a face sorting task. In each trial, multiple images of two facial identities were sorted into two corresponding piles. Following the sort, participants showed evidence of having learnt the faces, performing more accurately on a matching task with seen than unseen identities. Furthermore, ventral temporal event-related potentials were more negative in the N250 time range for previously-seen than previously-unseen identities. These effects appear to demonstrate some degree of abstraction, rather than simple picture learning, as the neurophysiological and behavioural effects were observed with novel images of the previously-seen identities. The results provide evidence of the development of facial representations, allowing a window onto natural mechanisms of face learning

    The Use of a Numerical Weather Prediction Model to Simulate Near-Field Volcanic Plumes

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    In this paper, a state-of the art numerical weather prediction (NWP) model is used to simulate the near-field plume of a Plinian-type volcanic eruption. The NWP model is run at very high resolution (of the order of 100 m) and includes a representation of physical processes, including turbulence and buoyancy, that are essential components of eruption column dynamics. Results are shown that illustrate buoyant gas plume dynamics in an atmosphere at rest and in an atmosphere with background wind, and we show that these results agree well with those from theoretical models in the quiescent atmosphere. For wind-blown plumes, we show that features observed in experimental and natural settings are reproduced in our model. However, when comparing with predictions from an integral model using existing entrainment closures there are marked differences. We speculate that these are signatures of a difference in turbulent mixing for uniform and shear flow profiles in a stratified atmosphere. A more complex implementation is given to show that the model may also be used to examine the dispersion of heavy volcanic gases such as sulphur dioxide. Starting from the standard version of the weather research and forecasting (WRF) model, we show that minimal modifications are needed in order to model volcanic plumes. This suggests that the modified NWP model can be used in the forecasting of plume evolution during future volcanic events, in addition to providing a virtual laboratory for the testing of hypotheses regarding plume behaviour

    Trait evaluations of faces and voices: Comparing within- and between-person variability

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    Human faces and voices are rich sources of information that can vary in many different ways. Most of the literature on face/voice perception has focussed on understanding how people look and sound different to each other (between-person variability). However, recent studies highlight the ways in which the same person can look and sound different on different occasions (within-person variability). Across three experiments, we examined how within- and between-person variability relate to one another for social trait impressions by collecting trait ratings attributed to multiple face images and voice recordings of the same people. We find that within-person variability in social trait evaluations is at least as great as between-person variability. Using different stimulus sets across experiments, trait impressions of voices are consistently more variable within people than between people – a pattern that is only evident occasionally when judging faces. Our findings highlight the importance of understanding within-person variability, showing how judgements of the same person can vary widely on different encounters and quantify how this pattern differs for voice and face perception. The work consequently has implications for theoretical models proposing that voices can be considered ‘auditory faces’ and imposes limitations to the ‘kernel of truth’ hypothesis of trait evaluations

    InterFace : A software package for face image warping, averaging, and principal components analysis

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    We describe InterFace, a software package for research in face recognition. The package supports image warping, reshaping, averaging of multiple face images, and morphing between faces. It also supports principal components analysis (PCA) of face images, along with tools for exploring the “face space” produced by PCA. The package uses a simple graphical user interface, allowing users to perform these sophisticated image manipulations without any need for programming knowledge. The program is available for download in the form of an app, which requires that users also have access to the (freely available) MATLAB Runtime environment

    Prolongation of atrio-ventricular node conduction in a rabbit model of ischaemic cardiomyopathy: Role of fibrosis and connexin remodelling

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    Conduction abnormalities are frequently associated with cardiac disease, though the mechanisms underlying the commonly associated increases in PQ interval are not known. This study uses a chronic left ventricular (LV) apex myocardial infarction (MI) model in the rabbit to create significant left ventricular dysfunction (LVD) 8weeks post-MI. In vivo studies established that PQ interval increases by approximately 7ms (10%) with no significant change in average heart rate. Optical mapping of isolated Langendorff perfused rabbit hearts recapitulated this result; time to earliest activation of the LV was increased by 14ms (16%) in the LVD group. Intra-atrial and LV transmural conduction times were not altered in the LVD group. Isolated AVN preparations from the LVD group demonstrated a significantly longer conduction time (by approximately 20ms) between atrial and His electrograms than sham controls across a range of pacing cycle lengths. This difference was accompanied by increased effective refractory period and Wenckebach cycle length, suggesting significantly altered AVN electrophysiology post-MI. The AVN origin of abnormality was further highlighted by optical mapping of the isolated AVN. Immunohistochemistry of AVN preparations revealed increased fibrosis and gap junction proteins (connexin43 and 40) remodelling in the AVN of LVD animals compared to sham. A significant increase in myocyte-non-myocyte connexin co-localization was also observed after LVD. These changes may increase the electrotonic load experienced by AVN muscle cells and contribute to slowed conduction velocity within the AVN

    A new methodologic approach for clinico-pathologic correlations in invasive placenta previa accreta

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    BACKGROUND: The development of new management strategies for women presenting with placenta accreta spectrum requires quality epidemiology data which have so far been limited by the high variability in clinical and histopathologic data confirming the diagnosis at birth. OBJECTIVE: To evaluate the role of a new methodologic approach for the correlation of clinical and pathological data for women with a history of prior cesarean delivery diagnosed prenatally with placenta previa accreta. STUDY DESIGN: A modified pathologic technique for gross examination of hysterectomy specimens with placenta in-situ consisting of intra-operative examination, immediate post-operative examination and guided histologic sampling was used prospectively in a cohort of 24 patients with singleton pregnancies complicated by placenta low-lying/placenta previa accreta. The maternal characteristics, detailed ultrasound findings, surgical outcomes and histopathologic examination were compared with those of a group of 24 patients with similar clinical characteristics where a standard pathologic examination method was used. RESULTS: The median reporting time for obtaining the complete histopathology results including the microscopic examination was significantly shorter (7 vs 15 days; P<0.001) and the median number of samples taken for histologic examination significantly lower (4 vs 14 samples; P<0.001) in the study group than in the controls. The number of histologic slides showing villous invasion was significantly higher (2 vs 1 slides; P=0.002) and the ratio of the number of samples taken to the numbers of slides confirming villous invasion was significantly lower (2 vs 9; P<0.001) in the study group than in the controls. In all cases of the study group, intra-operative examination identified a dense tangled bed of vessels or multiple vessels running laterally and cranio-caudally in the uterine serosa above the placental insertion which were no longer visible during immediate gross post-operative examination of the hysterectomy specimens. Immediate post-operative dissection enables the differential diagnosis between focal and large increta areas, and between abnormally adherent placenta and invasive placenta accreta. CONCLUSIONS: Valuable clinical information on the serosal vascularity, uterine dehiscence and extension of the accreta area is added with the description of the macroscopic examination during the surgical procedure and immediate dissection of the specimen. This methodological approach is cost-effective and increases the quality of the histologic sampling. It thus provides more accurate correlations with the clinical data and more accurate epidemiologic data collection. Perinatal pathologists should be part of multidisciplinary teams involved the management placenta accreta spectrum disorders

    Audiovisual integration in social evaluation

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    Our social evaluation of other people is influenced by their faces and their voices. However, rather little is known about how these channels combine in forming "first impressions." Over 5 experiments, we investigate the relative contributions of facial and vocal information for social judgments: dominance and trustworthiness. The experiments manipulate each of these sources of information within-person, combining faces and voices giving rise to different social attributions. We report that vocal pitch is a reliable source of information for judgments of dominance (Study 1), but not trustworthiness (Study 4). Faces and voices make reliable, but independent, contributions to social evaluation. However, voices have the larger influence in judgments of dominance (Study 2), whereas faces have the larger influence in judgments of trustworthiness (Study 5). The independent contribution of the 2 sources appears to be mandatory, as instructions to ignore 1 channel do not eliminate its influence (Study 3). Our results show that information contained in both the face and the voice contributes to first impression formation. This combination is, to some degree, outside conscious control, and the weighting of channel contribution varies according the trait being perceived. (PsycINFO Database Recor

    Choosing face : The curse of self in profile image selection

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    This research was supported by Australian Research Council grants to DW (LP130100702) and CS (DP170104602), postdoctoral research support from the Australian Research Council Centre of Excellence in Cognition and its Disorders, University of Western Australia (CE110001021) and an ESRC Overseas Institutional Visit award (ES/1900748/1) to CS. The authors thank Manuela Tan and undergraduate volunteers at the UNSW School of Psychology for assisting with the pilot work that led to this research.Peer reviewedPublisher PD

    Passport officers' errors in face matching

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    Photo-ID is widely used in security settings, despite research showing that viewers find it very difficult to match unfamiliar faces. Here we test participants with specialist experience and training in the task: passport-issuing officers. First, we ask officers to compare photos to live ID-card bearers, and observe high error rates, including 14% false acceptance of 'fraudulent' photos. Second, we compare passport officers with a set of student participants, and find equally poor levels of accuracy in both groups. Finally, we observe that passport officers show no performance advantage over the general population on a standardised face-matching task. Across all tasks, we observe very large individual differences: while average performance of passport staff was poor, some officers performed very accurately--though this was not related to length of experience or training. We propose that improvements in security could be made by emphasising personnel selection
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