1,598 research outputs found

    In vivo functional and myeloarchitectonic mapping of human primary auditory areas

    Get PDF
    In contrast to vision, where retinotopic mapping alone can define areal borders, primary auditory areas such as A1 are best delineated by combining in vivo tonotopic mapping with postmortem cyto- or myeloarchitectonics from the same individual. We combined high-resolution (800 ÎŒm) quantitative T(1) mapping with phase-encoded tonotopic methods to map primary auditory areas (A1 and R) within the "auditory core" of human volunteers. We first quantitatively characterize the highly myelinated auditory core in terms of shape, area, cortical depth profile, and position, with our data showing considerable correspondence to postmortem myeloarchitectonic studies, both in cross-participant averages and in individuals. The core region contains two "mirror-image" tonotopic maps oriented along the same axis as observed in macaque and owl monkey. We suggest that these two maps within the core are the human analogs of primate auditory areas A1 and R. The core occupies a much smaller portion of tonotopically organized cortex on the superior temporal plane and gyrus than is generally supposed. The multimodal approach to defining the auditory core will facilitate investigations of structure-function relationships, comparative neuroanatomical studies, and promises new biomarkers for diagnosis and clinical studies

    Unlocking the Mysteries of TDP-43

    Get PDF

    Prospective motion correction of 3D echo-planar imaging data for functional MRI using optical tracking.

    Get PDF
    We evaluated the performance of an optical camera based prospective motion correction (PMC) system in improving the quality of 3D echo-planar imaging functional MRI data. An optical camera and external marker were used to dynamically track the head movement of subjects during fMRI scanning. PMC was performed by using the motion information to dynamically update the sequence's RF excitation and gradient waveforms such that the field-of-view was realigned to match the subject's head movement. Task-free fMRI experiments on five healthy volunteers followed a 2×2×3 factorial design with the following factors: PMC on or off; 3.0mm or 1.5mm isotropic resolution; and no, slow, or fast head movements. Visual and motor fMRI experiments were additionally performed on one of the volunteers at 1.5mm resolution comparing PMC on vs PMC off for no and slow head movements. Metrics were developed to quantify the amount of motion as it occurred relative to k-space data acquisition. The motion quantification metric collapsed the very rich camera tracking data into one scalar value for each image volume that was strongly predictive of motion-induced artifacts. The PMC system did not introduce extraneous artifacts for the no motion conditions and improved the time series temporal signal-to-noise by 30% to 40% for all combinations of low/high resolution and slow/fast head movement relative to the standard acquisition with no prospective correction. The numbers of activated voxels (p<0.001, uncorrected) in both task-based experiments were comparable for the no motion cases and increased by 78% and 330%, respectively, for PMC on versus PMC off in the slow motion cases. The PMC system is a robust solution to decrease the motion sensitivity of multi-shot 3D EPI sequences and thereby overcome one of the main roadblocks to their widespread use in fMRI studies

    Neuropathologic basis of frontotemporal dementia in progressive supranuclear palsy.

    Get PDF
    BackgroundProgressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by neuronal loss in the extrapyramidal system with pathologic accumulation of tau in neurons and glia. The most common clinical presentation of PSP, referred to as Richardson syndrome, is that of atypical parkinsonism with vertical gaze palsy, axial rigidity, and frequent falls. Although cognitive deficits in PSP are often ascribed to subcortical dysfunction, a subset of patients has dementia with behavioral features similar to the behavioral variant of frontotemporal dementia. In this study we aimed to identify the clinical and pathological characteristics of PSP presenting with frontotemporal dementia.MethodsIn this study, we compared clinical and pathologic characteristics of 31 patients with PSP with Richardson syndrome with 15 patients with PSP with frontotemporal dementia. For pathological analysis, we used semiquantitative methods to assess neuronal and glial lesions with tau immunohistochemistry, as well image analysis of tau burden using digital microscopic methods.ResultsWe found greater frontal and temporal neocortical neuronal tau pathology in PSP with frontotemporal dementia compared with PSP with Richardson syndrome. White matter tau pathology was also greater in PSP with frontotemporal dementia than PSP with Richardson syndrome. Genetic and demographic factors were not associated with atypical distribution of tau pathology in PSP with frontotemporal dementia.ConclusionsThe results confirm the subset of cognitive-predominant PSP mimicking frontotemporal dementia in PSP. PSP with frontotemporal dementia has distinct clinical features that differ from PSP with Richardson syndrome, as well as differences in distribution and density of tau pathology. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society

    Status, Testosterone, and Human Intellectual Performance: Stereotype Threat as Status Concern

    Get PDF
    Results from two experiments suggest that stereotype-threat effects are special cases of a more general process involving the need to maintain or enhance status. We hypothesized that situations capable of confirming a performance stereotype might represent either a threat to status or an opportunity for enhancement of status, depending on the nature of the stereotype. The positive relationship between baseline testosterone and status sensitivity led us to hypothesize that high testosterone levels in males and females would amplify existing performance expectations when gender-based math-performance stereotypes were activated. In Study 1, high-testosterone females performed poorly on a math test when a negative performance stereotype was primed. In Study 2, high-testosterone males excelled on a math test when a positive performance stereotype was primed. The moderating effect of testosterone on performance suggests that a stereotype-relevant situation is capable of conferring either a loss or a gain of status on targets of the stereotype.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Progressive Apraxia of Speech: Might There Be Subtypes?

    Get PDF
    This study examined speech and language characteristics of three groups of individuals with neurodegenerative disease: (1) primary progressive apraxia of speech (AOS) without aphasia (N=18), (2) agrammatic primary progressive aphasia (agPPA) less severe than AOS (N=10), and (3) agPPA more severe than AOS (N=9). Findings indicate that differences in the predominant characteristics of AOS (predominance of articulatory versus prosodic abnormalities) distributed differently among the three groups, independent of AOS severity. Neuroimaging findings also differed among the groups. Results suggest that neurodegenerative AOS may include perceptually distinguishable subtypes that are related to the presence or absence of aphasia and neuroimaging findings

    Insects as food and feed: European perspectives on recent research and future priorities

    Get PDF
    This paper discusses the current state and priorities of Europe-based research on insects as food and feed, based on presentations at a workshop held in December 2015, and discussions that followed. We divide research into studies that focus on farming, health and nutrition, and those that prioritise psychological, social and political concerns. Edible insects are not necessarily universally beneficial. However, certain food insects can convert organic waste material, and provide nutrient-rich protein for humans and animals. Recent research is not concordant when trying to identify social and psychological barriers to insects as food in Europe, indicating the complexity of the issue of consumer acceptance. Innovative means of marketing insects as food include 3D printing, scientific comics, and the promotion of rural food culture in an urban setting. Edible insects are intimately connected to strong cultural and regional values, and their increasing commercialisation may empower and/or disenfranchise those who hold such values. We conclude with a discussion about the future priorities of edible insect research in Europe. We acknowledge the political nature of the ‘entomophagy’ movement. With legislative change, the insect food industry potential presents an opportunity to challenge the dynamics of current food systems. We identify the following priorities for future research: the need to better understand environmental impacts of insect procurement on both a regional and global scale, to investigate factors affecting the safety and quality of insect foods, to acknowledge the complexity of consumer acceptance, and to monitor the social and economic impacts of this growing industry.The authors would like to thank the Great British Sasakawa Foundation and BioBridge Ltd for financial support. Jonas House’s research received funding from the Economic and Social Research Council, grant number ES/J500215/1

    TEMPERATURE-DEPENDENCE OF DOMAIN-WALL COERCIVE FIELD IN MAGNETIC GARNET-FILMS

    Get PDF
    The coercive properties of magnetically uniaxial liquid-phase epitaxy garnet films were investigated between 10 K and the Neel temperature (T(N) less-than-or-equal-to 500 K). Two independent methods, the results of which are nearly identical (magnetical response of oscillating domain walls and the method of coercive loops measured in a vibrating sample magnetometer), were used. Besides the usual domain-wall coercive field, H(dw), the critical coercive pressure, p(dw), was also introduced as it describes in a direct way the interactions of the domain walls with the wall-pinning traps. Both H(dw) and p(dw) were found to increase exponentially with decreasing temperature. Three different types of wall-pinning traps were identified in the sample and their strength, their rate of change with temperature, and their temperature range of activity were determined
    • 

    corecore