563 research outputs found

    Dynamics of trimming the content of face representations for categorization in the brain

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    To understand visual cognition, it is imperative to determine when, how and with what information the human brain categorizes the visual input. Visual categorization consistently involves at least an early and a late stage: the occipito-temporal N170 event related potential related to stimulus encoding and the parietal P300 involved in perceptual decisions. Here we sought to understand how the brain globally transforms its representations of face categories from their early encoding to the later decision stage over the 400 ms time window encompassing the N170 and P300 brain events. We applied classification image techniques to the behavioral and electroencephalographic data of three observers who categorized seven facial expressions of emotion and report two main findings: (1) Over the 400 ms time course, processing of facial features initially spreads bilaterally across the left and right occipito-temporal regions to dynamically converge onto the centro-parietal region; (2) Concurrently, information processing gradually shifts from encoding common face features across all spatial scales (e.g. the eyes) to representing only the finer scales of the diagnostic features that are richer in useful information for behavior (e.g. the wide opened eyes in 'fear'; the detailed mouth in 'happy'). Our findings suggest that the brain refines its diagnostic representations of visual categories over the first 400 ms of processing by trimming a thorough encoding of features over the N170, to leave only the detailed information important for perceptual decisions over the P300

    Emotional Facial Expression Detection in the Peripheral Visual Field

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    BACKGROUND: In everyday life, signals of danger, such as aversive facial expressions, usually appear in the peripheral visual field. Although facial expression processing in central vision has been extensively studied, this processing in peripheral vision has been poorly studied. METHODOLOGY/PRINCIPAL FINDINGS: Using behavioral measures, we explored the human ability to detect fear and disgust vs. neutral expressions and compared it to the ability to discriminate between genders at eccentricities up to 40°. Responses were faster for the detection of emotion compared to gender. Emotion was detected from fearful faces up to 40° of eccentricity. CONCLUSIONS: Our results demonstrate the human ability to detect facial expressions presented in the far periphery up to 40° of eccentricity. The increasing advantage of emotion compared to gender processing with increasing eccentricity might reflect a major implication of the magnocellular visual pathway in facial expression processing. This advantage may suggest that emotion detection, relative to gender identification, is less impacted by visual acuity and within-face crowding in the periphery. These results are consistent with specific and automatic processing of danger-related information, which may drive attention to those messages and allow for a fast behavioral reaction

    Sequential biventricular pacing improves regional contractility, longitudinal function and dyssynchrony in patients with heart failure and prolonged QRS

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    <p>Abstract</p> <p>Aims</p> <p>Biventricular pacing (BiP) is an effective treatment in systolic heart failure (HF) patients with prolonged QRS. However, approximately 35% of the patients receiving BiP are classified as non-responders. The aim of this study is to evaluate the acute effects of VV-optimization on systolic heart function.</p> <p>Methods</p> <p>Twenty-one HF patients aged 72 (46-88) years, QRS 154 (120-190) ms, were studied with echocardiography, Tissue Doppler Imaging (TDI) and 3D-echo the first day after receiving a BiP device. TDI was performed; during simultaneous pacing (LV-lead pacing 4 ms before the RV-lead) and during sequential pacing (LV 20 and 40 ms before RV and RV 20 and 40 ms before LV-lead pacing). Systolic heart function was studied by tissue tracking (TT) for longitudinal function and systolic maximal velocity (SMV) for regional contractility and signs of dyssynchrony assessed by time-delays standard deviation of aortic valve opening to SMV, AVO-SMV/SD and tissue synchronization imaging (TSI).</p> <p>Results</p> <p>The TT mean value preoperatively was 4,2 ± 1,5 and increased at simultaneous pacing to 5,0 ± 1,2 mm (p < 0,05), and at best VV-interval to 5,4 ± 1,2 (p < 0,001). Simultaneous pacing achieved better TT distance compared with preoperative in 16 patients (76%). However, it was still higher after VV-optimization in 12 patients 57%. Corresponding figures for SMV were 3,0 ± 0,7, 3,5 ± 0,8 (p < 0,01), and 3,6 ± 0,8 (p < 0,001). Also dyssynchrony improved.</p> <p>Conclusions</p> <p>VV-optimization in the acute phase improves systolic heart function more than simultaneous BiP pacing. Long-term effects should be evaluated in prospective randomized trials.</p

    Use, acceptability and impact of booklets designed to support mental health self-management and help seeking in schools:Results of a large randomised controlled trial in England

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    Mental health booklets may provide a low-cost means of promoting mental health self-management and help seeking in schools. The aim of the study was to assess the (a) use, (b) acceptability and (c) impact of booklets for students in primary (10-11 years) and secondary school (12-13 years) alone and in conjunction with funding for targeted mental health support. This was a 2 × 2 factorial cluster randomized controlled trial, in which 846 schools in England were randomly allocated to receive/not receive: (1) booklets for students containing information on mental health self-management and help seeking, and (2) funding for mental health support as part of a national mental health initiative. 14,690 students (8139 primary, 6551 secondary) provided self-report on mental health, quality of life (baseline and 1 year follow-up) and help seeking (follow-up). (a) Approximately, 40 % primary school students and 20 % secondary school students reported seeing the booklets. (b) Of these, 87 % of primary school students reported that the booklet was 'very helpful' or 'quite helpful', compared with 73 % in secondary school. (c) There was no detectable impact of booklets on mental health, quality of life or help seeking, either alone or in conjunction with additional funding through the national mental health initiative. Lack of discernable impact of booklets underscores the need for caution in adopting such an approach. However, it is feasible that the impact was obscured by low uptake or that booklets may be more effective when used in a targeted way

    Pre-implant right ventricular function might be an important predictor of the response to cardiac resynchronization therapy

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    <p>Abstract</p> <p>Objective</p> <p>Cardiac resynchronization therapy is proven efficacious in patients with heart failure (HF). Presence of biventricular HF is associated with a worse prognosis than having only left ventricular (LV) HF and pacing might deteriorate heart function. The aim of the study was to assess a possible significance of right ventricular (RV) pre-implant systolic function to predict response to CRT.</p> <p>Design</p> <p>We studied 22 HF-patients aged 72 ± 11 years, QRS-duration 155 ± 20 ms and with an LV ejection fraction (EF) of 26 ± 6% before and four weeks after receiving a CRT-device.</p> <p>Results</p> <p>There were no changes in LV diameters or end systolic volume (ESV) during the study. However, end diastolic volume (EDV) decreased from 226 ± 71 to 211 ± 64 ml (p = 0.02) and systolic maximal velocities (SMV) increased from 2.2 ± 0.4 to 2.6 ± 0.9 cm/s (p = 0.04). Pre-implant RV-SMV (6.2 ± 2.6 cm/s) predicted postoperative increase in LV contractility, p = 0.032.</p> <p>Conclusions</p> <p>Pre-implant decreased RV systolic function might be an important way to predict a poor response to CRT implicating that other treatments should be considered. Furthermore we found that 3D- echocardiography and Tissue Doppler Imaging were feasible to detect short-term changes in LV function.</p

    Tolerability of gefitinib in patients receiving treatment in everyday clinical practice

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    Gefitinib (‘Iressa’, ZD1839), an epidermal growth factor receptor tyrosine kinase inhibitor, has recently been approved in several countries for use in advanced or metastatic non-small-cell lung cancer (NSCLC). In contrast to chemotherapies, which are generally used at or near their maximum-tolerated dose (MTD), gefitinib is used at an optimal biological dose (250 mg day−1), which is substantially below its MTD, minimising the risk of adverse events without compromising efficacy. Tolerability data from the compassionate use of gefitinib in the ‘Iressa’ Expanded Access Programme support the favourable safety profile of the agent reported in Phase I and II trials. In both settings, the majority of adverse drug reactions were mild/moderate and consisted mainly of grade 1/2 diarrhoea and skin rash. Although skin rash has been suggested to predict response to gefitinib, available data do not support this hypothesis. Overall, these tolerability data demonstrate that gefitinib has a relatively benign side-effect profile and is a well-tolerated treatment option for patients with previously treated NCSLC, who currently have few alternatives

    Cultural Diversity and Saccade Similarities: Culture Does Not Explain Saccade Latency Differences between Chinese and Caucasian Participants

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    A central claim of cultural neuroscience is that the culture to which an individual belongs plays a key role in shaping basic cognitive processes and behaviours, including eye movement behaviour. We previously reported a robust difference in saccade behaviour between Chinese and Caucasian participants; Chinese participants are much more likely to execute low latency express saccades, in circumstances in which these are normally discouraged. To assess the extent to which this is the product of culture we compared a group of 70 Chinese overseas students (whose primary cultural exposure was that of mainland China), a group of 45 participants whose parents were Chinese but who themselves were brought up in the UK (whose primary cultural exposure was western European) and a group of 70 Caucasian participants. Results from the Schwartz Value Survey confirmed that the UK-Chinese group were culturally similar to the Caucasian group. However, their patterns of saccade latency were identical to the mainland Chinese group, and different to the Caucasian group. We conclude that at least for the relatively simple reflexive saccade behaviour we have investigated, culture cannot explain the observed differences in behaviour

    Treatment of non-small-cell lung cancer: a perspective on the recent advances and the experience with gefitinib

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    Worldwide, non-small-cell lung cancer (NSCLC) is a leading cause of cancer-related mortality and, until screening detects early disease, treatment for the majority of patients will consist of radiation therapy, chemotherapy or combinations thereof. Modern mono and doublet chemotherapy regimens have translated into modest increases in life expectancy and improved quality of life, but at the expense of systemic and pulmonary adverse events (AEs). There is a great unmet need to provide effective therapy for advanced NSCLC that does not have the toxicity burden of conventional chemotherapy and radiotherapy. Novel drugs that inhibit a range of growth factor receptors, such as the epidermal growth factor receptor tyrosine kinase inhibitors gefitinib (‘Iressa’) and erlotinib (‘Tarceva’) or the monoclonal antibody cetuximab (‘Erbitux’), have recently been evaluated. Having demonstrated antitumour activity and rapid symptom improvement in pretreated patients with advanced NSCLC, gefitinib was approved in the USA, Japan and other countries. Gefitinib is well tolerated with a low incidence of grade 3/4 AEs. Interstitial lung disease has been reported in a small number of patients receiving gefitinib, although this may be attributed to other treatments and conditions. Nevertheless, although the use of novel treatments requires vigilance for unexpected AEs such as pulmonary toxicity, in this area of high unmet clinical need, the benefits outweigh the risks in patients for whom no other proven effective treatment exists

    Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

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    A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%
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