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of 33799 results
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AbstractIntroduction: The striatum, a fundamental component of the basal ganglia is the main structure compromised in Huntington's disease (HD). However, it is still unknown if degeneration in other brain regions could also contribute to the major motor signs i...Nov 15, 2016
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AbstractThe basal forebrain (BF) is among the first brain structures to degenerate in Alzheimer’s disease (AD). In cognitively normal older adults expressing abnormal cerebrospinal levels of beta amyloid, we previously demonstrated with in vivo structural magne...Nov 14, 2017
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Repetition suppression, or fMRI-adaptation, refers to decreased neural activity for repeated versus novel stimuli as measured with functional magnetic resonance imaging (fMRI). Recently, this technique has been widely used, especially in probing the plasticity of the nervous system and theOct 24, 2007
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The primary somatosensory cortex (S1) can be subdivided cytoarchitectonically into four distinct Brodmann areas (3a, 3b, 1, and 2), but these areas have never been successfully delineated in vivo in single human subjects. Here, we demonstrate the functional parcellation of four areas of S1 in individual human subjects based on high-resolution functional MRI measurements made at 7 T using vibrotactile stimulation. By stimulating four sites along the length of the index finger, we were able to identify and locate map reversals of the base to tip representation of the index finger in S1. We suggest that these reversals correspond to the areal borders between the mirrored representations in the four Brodmann areas, as predicted from electrophysiology measurements in nonhuman primates. In all subjects, maps were highly reproducible across scanning sessions and stable over weeks. In four of the six subjects scanned, four, mirrored, within-finger somatotopic maps defining the extent of the Brodmann areas could be...Nov 7, 2012
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An event-related functional magnetic resonance imaging study of prefrontal cortex was conducted during which subjects performed a visual “oddball” target detection task. Exemplars of three stimulus categories were presented at a rate of one per 1.5 sec for 10 runs, each consisting of 132 trials. Standards were color squares of varying sizes that were presented on ∼92% of trials. Targets were color circles of varying sizes presented irregularly on ∼4% of trials. Novels were pictures of everyday objects that were also presented irregularly on ∼4% of trials. Ten subjects participated in two separate sessions in which they were required to count mentally or to push a button whenever a target appeared. Targets evoked activation within prefrontal cortex, primarily within the middle frontal gyri (MFG). This MFG activation did not differ as a function of the required response. Novels did not evoke significant activity within this region despite evidence from a separate behavioral and event-related potential study ...Sep 1, 2000
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AbstractAutism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by altered social, communicative, and repetitive behaviors, though of unknown etiology. The Van de Water lab has previously identified a set of potentially pathogenic autoanti...Nov 9, 2021
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Cardiovascular exercise (CE) is a promising intervention strategy to facilitate cognition and motor learning in healthy and diseased populations of all ages. CE elevates humoral parameters, such as growth factors, and stimulates brain changes potentially relevant for learning and behavioral adaptations. However, the causal relationship between CE-induced brain changes and human's ability to learn remains unclear. We tested the hypothesis that CE elicits a positive effect on learning via alterations in brain structure (morphological changes of gray and white matter) and function (functional connectivity and cerebral blood flow in resting state). We conducted a randomized controlled trial with healthy male and female human participants to compare the effects of a 2 week CE intervention against a non-CE control group on subsequent learning of a challenging new motor task (dynamic balancing; DBT) over 6 consecutive weeks. We used multimodal neuroimaging [T1-weighted magnetic resonance imaging (MRI), diffusion-...Mar 18, 2020
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AbstractHuntington’s disease (HD) is caused by an expansion of the CAG repeat in the huntingtin gene and is characterized predominately by striatal neurodegeneration. HD therapeutic development would be facilitated by translatable biomarkers of treatment respon...Oct 22, 2019
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Functional magnetic resonance imaging (fMRI) combined with population receptive field (pRF) mapping allows for associating positions on the visual cortex to areas on the visual field. Apart from applications in healthy subjects, this method can also be used to examine dysfunctions in patients suffering from partial visual field losses. While such objective measurement of visual deficits (scotoma) is of great importance for, e.g., longitudinal studies addressing treatment effects, it requires a thorough assessment of accuracy and reproducibility of the results obtained. In this study, we quantified the reproducibility of pRF mapping results within and across sessions in case of central visual field loss in a group of 15 human subjects. We simulated scotoma by masking a central area of 2° radius from stimulation to establish ground-truth conditions. This study was performed on a 7T ultra-high field MRI scanner for increased sensitivity. We found excellent intrasession and intersession reproducibility for the...Sep 1, 2022
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How humans achieve such a high degree of prosocial behavior is a subject of considerable interest. Exploration of the neural foundations of human prosociality has garnered significant attention in recent decades. Nevertheless, the neural mechanisms underlying human prosociality remain to be elucidated. To address this knowledge gap, we analyzed multimodal brain imaging data and data from 15 economic games. The results revealed several significant associations between brain characteristics and prosocial behavior, including stronger interhemispheric connectivity and larger corpus callosum volume. Greater functional segregation and integration, alongside fewer myelin maps combined with a thicker cortex, were linked to prosocial behavior, particularly within the social brain regions. The current study demonstrates that these metrics serve as brain markers of human prosocial behavior and provides novel insights into the structural and functional brain basis of human prosocial behavior.Mar 1, 2025