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1981 - 1990
of 33813 results
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The human brain is asymmetric in gross structure as well as functional organization. However, the developmental basis and trajectory of this asymmetry is unclear, and its relationship(s) to functional and cognitive development, especially language, remain to be fully elucidated. During infancy and early childhood, in concert with cortical gray matter growth, underlying axonal bundles become progressively myelinated. This myelination is critical for efficient and coherent interneuronal communication and, as revealed in animal studies, the degree of myelination changes in response to environment and neuronal activity. Using a novel quantitative magnetic resonance imaging method to investigate myelin content in vivo in human infants and young children, we investigated gross asymmetry of myelin in a large cohort of 108 typically developing children between 1 and 6 years of age, hypothesizing that asymmetry would predict language abilities in this cohort. While asymmetry of myelin content was evident in multipl...Oct 9, 2013
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Bin Ji, Hiroyuki Kaneko, Takafumi Minamimoto, Haruhisa Inoue, Hiroki Takeuchi, et al. (see pages [11544–11558][1]) A major goal of neuroscience research is to develop treatments for neurodegenerative diseases and CNS injuries. Strategies for doing this include promoting growth of damaged orNov 9, 2016
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AbstractIntroduction: Deletions and duplications of the chromosome 16p11.2 locus are associated with autism spectrum disorders, schizophrenia, cognitive and language deficits. Diffusion tensor imaging (DTI) studies have reported increases and decreases in fract...Nov 10, 2021
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AbstractThe medial temporal lobe (MTL) consists of the hippocampus and extra-hippocampal cortical structures, and plays an essential role in memory function. Specific MTL subregions are differentially involved in both normal memory function and various neurolog...Nov 12, 2016
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Chemosensory communication of affect and motivation is ubiquitous among animals. In humans, emotional expressions are naturally associated with faces and voices. Whether chemical signals play a role as well has hardly been addressed. Here, we use functional magnetic resonance imaging to show that the right orbitofrontal cortex, right fusiform cortex, and right hypothalamus respond to airborne natural human sexual sweat, indicating that this particular chemosensory compound is encoded holistically in the brain. Our findings provide neural evidence that socioemotional meanings, including the sexual ones, are conveyed in the human sweat.Dec 31, 2008
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Task-based functional magnetic resonance imaging (tfMRI) has been widely used to induce functional brain activities corresponding to various cognitive tasks. A relatively under-explored question is whether there exist fundamental differences in fMRI signal composition patterns that can effectively classify the task states of tfMRI data, furthermore, whether there exist key functional components in characterizing the diverse tfMRI signals. Recently, fMRI signal composition patterns of multiple tasks have been investigated via deep learning models, where relatively large populations of fMRI datasets are indispensable and the neurologic meaning of their results is elusive. Thus, the major challenges arise from the high dimensionality, low signal-to-noise ratio, interindividual variability, a small sample size of fMRI data, and the explainability of classification results. To address the above challenges, we proposed a computational framework based on group-wise hybrid temporal and spatial sparse representatio...May 1, 2022
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The transition from adolescence to adulthood is associated with brain remodeling in the final stages of developmental growth. It is also a period when a large proportion of this age group engages in binge alcohol drinking (occasional consumption of four to five drinks leading to intoxication) and heavy alcohol drinking (binge drinking on ≥5 d in a month). Here we report on magnetic resonance imaging of developmental changes in the brain occurring during late adolescence and early adulthood (3.5–7.5 years of age) in a rhesus macaque model of alcohol self-administration. Monkeys were imaged prior to alcohol exposure, and following ∼6 and ∼12 months of daily (22 h/d) access to ethanol and water. The results revealed that the brain volume increases by 1 ml/1.87 years throughout the late adolescence and early adulthood in controls. Heavy alcohol drinking reduced the rate of brain growth by 0.25 ml/year per 1 g/kg daily ethanol. Cortical volume increased throughout this period with no significant effect of alcoh...Mar 1, 2019
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AbstractRecent theoretical studies as well as measurements in phantoms have suggested that neural bulk activity like alpha waves, which are believed to involve current dipoles of up to 100nAm in humans, may lead to a modulation of the phase and amplitude of the...Nov 6, 2007
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The mechanisms underlying accumulation of Alzheimer's disease (AD)-related tau pathology outside of the medial temporal lobe (MTL) in older adults are unknown but crucial to understanding cognitive decline. A growing body of evidence from human and animal studies strongly implicates neural connectivity in the propagation of tau in humans, but the pathways of neocortical tau spread and its consequences for cognitive function are not well understood. Using resting state functional magnetic resonance imaging (fMRI) and tau PET imaging from a sample of 97 male and female cognitively normal older adults, we examined MTL structures involved in medial parietal tau accumulation and associations with memory function. Functional connectivity between hippocampus (HC) and retrosplenial cortex (RsC), a key region of the medial parietal lobe, was associated with tau in medial parietal lobe. By contrast, connectivity between entorhinal cortex (EC) and RsC did not correlate with medial parietal lobe tau. Further, greater ...Oct 20, 2021
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AbstractPrior studies have used fMRI to measure the onset of neural activity from a stable baseline with a temporal precision on the order of 100 msec. Many important neural processes, however, reveal themselves as increases in activity that lie on top of another neural response. We attempted to determine whether fMRI could measure the timing of an increase that occurred 200 msec after initial response. Subjects viewed stimuli from three conditions. In our baseline condition, a low contrast flickering checkerboard was presented for 600 msec. We added a 400 msec contrast increment to this stimulus either at a 200 msec delay or immediately upon stimulus presentation; thus in the delay condition the low contrast checkerboard increased its contrast after 200 msec and remained high contrast for 400 msec, while in the immediate condition a high contrast flickering checkerboard reduced its contrast after 400 msec and remained low for 200 msec. We acquired BOLD fMR images every 100 msec (TR) while these conditions were pr...Nov 13, 2005