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The stages of integration leading from local feature analysis to object recognition were explored in human visual cortex by using the technique of functional magnetic resonance imaging. Here we report evidence for object-related activation. Such activation was located at the lateral-posterior aspect of the occipital lobe, just abutting the posterior aspect(More)
BACKGROUND AND PURPOSE Stroke recovery mechanisms remain incompletely understood, particularly for subjects with cortical stroke, in whom limited data are available. We used functional magnetic resonance imaging to compare brain activations in normal controls and subjects who recovered from hemiparetic stroke. METHODS Functional magnetic resonance imaging(More)
Previous studies have found that the P300 or P3 event-related potential (ERP) component is useful in the diagnosis and treatment of many disorders that influence CNS function. However, the anatomic locations of brain regions involved in this response are not precisely known. In the present event-related functional magnetic resonance imaging (fMRI) study,(More)
BACKGROUND Functional MRI (fMRI) is of potential value in determining hemisphere dominance for language in epileptic patients. OBJECTIVE To develop and validate an fMRI-based method of determining language dominance for patients with a wide range of potentially operable brain lesions in addition to epilepsy. METHODS Initially, a within-subjects design(More)
Candidate brain regions constituting a neural network for preattentive phonetic perception were identified with fMRI and multivariate multiple regression of imaging data. Stimuli contrasted along speech/nonspeech, acoustic, or phonetic complexity (three levels each) and natural/synthetic dimensions. Seven distributed brain regions' activity correlated with(More)
Recordings in experimental animals have detailed the tonotopic organization of auditory cortex, including the presence of multiple tonotopic maps. In contrast, relatively little is known about tonotopy within human auditory cortex, for which even the number and location of tonotopic maps remains unclear. The present study begins to develop a more complete(More)
PURPOSE To determine the accuracy of functional MR imaging in locating language areas for planning surgical resection. METHODS Intraoperative photographs were digitized and overlaid on functional MR language maps. The sensitivity and specificity of functional MR imaging for identifying language areas were determined for five different language tasks by(More)
OBJECTIVE To investigate the relationship between white matter abnormalities and impairment of gait and balance in older persons. METHODS Quantitative MRI was used to evaluate the brain tissue compartments of 28 older individuals separated into normal and impaired groups on the basis of mobility performance testing using the Short Physical Performance(More)
Conventional clinical neuroimaging is insensitive to axonal injury in traumatic brain injury (TBI). Immunocytochemical staining reveals changes to axonal morphology within hours, suggesting potential for diffusion-weighted magnetic resonance (MR) in early diagnosis and management of TBI. Diffusion tensor imaging (DTI) characterizes the three-dimensional(More)
Using functional magnetic resonance imaging (fMRI), we investigated whether the response of auditory and visual cortex was modulated by attending selectively to either heard or seen numbers presented simultaneously. Alternating attention between modalities modulated fMRI signal within the corresponding sensory cortex. This study provides evidence that(More)