Showing papers in "NeuroImage in 1999"

TL;DR: A set of automated procedures for obtaining accurate reconstructions of the cortical surface are described, which have been applied to data from more than 100 subjects, requiring little or no manual intervention.

TL;DR: A set of procedures for modifying the representation of the cortical surface to inflate it so that activity buried inside sulci may be visualized, cut and flatten an entire hemisphere, and transform a hemisphere into a simple parameterizable surface such as a sphere for the purpose of establishing a surface-based coordinate system are designed.

TL;DR: Functional magnetic resonance imaging results suggest that a distinct region in the left inferior frontal cortex is involved in semantic processing, whereas other regions may subserve phonological processes engaged during both semantic and phonological tasks.

TL;DR: Deconvolution may be effective in diminishing the hemodynamically imposed temporal blurring and may have potential applications in quantitating responses in eventrelated fMRI.

TL;DR: It is suggested that activations common to all subjects reflect aspects of functional anatomy that may be "typical" of the population from which that group was sampled, and these commonalities can be identified by a conjunction analysis of the activation effects.

TL;DR: In fMRI there are two classes of inference: one aims to make a comment about the "typical" characteristics of a population, and the other about "average" characteristics, which applies to studies of normal subjects that try to identify some qualitative aspect of normal functional anatomy.

TL;DR: The most efficient designs for evoked responses, as opposed to differential responses, require trial-free periods during which baseline levels can be attained, and the most efficient design is a conventional block design.

TL;DR: An atlas of the human cerebellum is prepared using high-resolution magnetic resonance-derived images warped into the proportional stereotaxic space of Talairach and Tournoux to provide a template for more precise identification of cerebellar topography in functional imaging studies in normals and clinical-pathologic correlations in patients.

TL;DR: Increasing the amount of to-be-maintained information, without any overt manipulation requirement, resulted in the recruitment of wide-spread frontal-lobe regions.

TL;DR: The utility of these methods for localizing relatively subtle structural changes that occur between childhood and adolescence has not been examined and the age effects observed appear to result from regions that consistently segment as gray matter in the younger group and consistently segments as white matter inThe older group.

TL;DR: The use of two different tasks in the same set of subjects allowed us to provide an unequivocal demonstration that the neural networks subserving spatial attention and working memory intersect at several frontoparietal sites, and support the view that major cognitive domains are represented by partially overlapping large-scale neural networks.

TL;DR: Two different clustering algorithms are presented and used to identify regions of similar activations in an fMRI experiment involving a visual stimulus and a novel metric is employed that measures the similarity between the activation stimulus and the fMRI signal.

TL;DR: A visualization method of magnetoencephalographic data that is based on minimum-norm estimates that can represent several local or distributed sources and does not need explicit a priori information is studied.

TL;DR: The overall finding that some aspects of the hemodynamic coupling between neural activity and BOLD fMRI signal change with age cautions against simple interpretations of the results of imaging studies that compare young and elderly subjects.

TL;DR: Only genuine microstructural analysis can define the borders between these cortical areas, and additional significant borders which do not correlate with visible changes in cytoarchitecture can be found within areas 3b and 1.

TL;DR: This paper presents a topographical description of the regions showing significant contributions of cardiac-related signal variance in the brain and suggests that reduced sensitivity due to cardiac-induced noise in the BOLD signal is systematically greater in specific areas, typically near major blood vessels.

TL;DR: It is demonstrated that in VS patients various prefrontal and premotor areas have in common that they are less tightly connected with the posterior cingulate cortex than in normal controls, which provides a strong argument for an alteration of cortical connectivity inVS patients.

TL;DR: The results may suggest that alpha ERD reflects changes in the background oscillatory activity in wide cortical sensorimotor areas, whereas MRPs represent mainly increased, task-specific responses of SMA and contralateral M1-S1.

TL;DR: The results demonstrate that a noninvasive, multimodal brain imaging technique can reveal individual cortical brain activity with high temporal and spatial resolution, independent of a priori physiological assumptions.

TL;DR: Findings support the role of paralimbic structures as neural substrates of anticipatory anxiety and the failure to demonstrate behavioral and neurophysiological changes with the distractor task may reflect the modest increases in anxiety with the shock, the relatively simple distractionor task, and small sample size.

TL;DR: Significant drifting was present in data acquired from cadavers and nonhomogeneous phantoms and all pulse sequences tested, implying that scanner instabilities and not motion or physiological noise may be the major cause of the drift.

TL;DR: Three distinct regions in the left ventral occipitotemporal cortex appear to be important for converting orthography into phonology; their response to words irrespective of task is consistent with established psychological evidence that implicit phonological processing is stronger for words than objects.

TL;DR: Both exogenous (based on spatial priming) and endogenous ( based on expectancy cueing) shifts of attention are subserved by a common network of cortical and subcortical regions, however, the differences between the two tasks, especially in the degree of rightward asymmetry, suggests that the pattern of activation within this network may show variations that reflect the specific attributes of the attentional task.

TL;DR: The results suggest that spatial working memory tasks activate very similar cortical regions for school-age children and adults.

TL;DR: Anatomical atlases based on this procedure provide a new tool for the interpretation of structural data obtained from functional imaging techniques, and offers a new level of reproducibility and observer independence.

TL;DR: For instance, this article employed fMRI to index neural activity in prefrontal cortex during tests of recognition and source memory and found that high density recognition was associated with increased activity in right and, to a lesser extent, left, anterior prefrontal cortex (BA 10), replicating the findings of two previous PET studies.

TL;DR: The analysis of the decreases and increases in the BOLD signal across the STD, DEV, and rest conditions suggests that the left posterior superior temporal gyrus is implicated in the preattentive change detection of acoustic changes in speech as well as nonspeech stimuli, whereas the left supramarginal g Cyrus is more specifically engaged in the detection of changes in phonological units.

TL;DR: Analysis of quantitative and nonquantitative data showed the same pattern of results, suggesting that, for clinical purposes, quantitation and invasive arterial cannulation can be avoided and should facilitate a wider application of the technique and the extension of SPM clinical analysis to H215O PET or high resolution SPECT perfusion studies.

TL;DR: An alternative method of data analysis is proposed that emphasizes global integration rather than isolated regional changes in response to psychological tasks, and suggests that brain abnormalities in schizophrenia are best characterized as a disturbance in the integration of activity across a number of brain regions.

TL;DR: The receiver operator characteristic (ROC) method is used to compare the efficacy of various steps in calculating an activation map in the study of a single subject based on optimizing the ratio of the number of detected activations to thenumber of false-positive findings.