Precise timing of sound is crucial in music for both performing and listening. Indeed, listening to rhythmic sound sequences activates not only the auditory system but also the sensorimotor system. Previously, we showed the significance of neural beta-band oscillations (15-30 Hz) for the timing processing that involves such auditory-motor coordination.
View Article and Find Full Text PDFThe effects of physiological noise may significantly limit the reproducibility and accuracy of BOLD fMRI. However, physiological noise evidences a complex, undersampled temporal structure and is often non-orthogonal relative to the neuronally-linked BOLD response, which presents a significant challenge for identifying and removing such artifact. This paper presents a multivariate, data-driven method for the characterization and removal of physiological noise in fMRI data, termed PHYCAA (PHYsiological correction using Canonical Autocorrelation Analysis).
View Article and Find Full Text PDFSubject-specific artifacts caused by head motion and physiological noise are major confounds in BOLD fMRI analyses. However, there is little consensus on the optimal choice of data preprocessing steps to minimize these effects. To evaluate the effects of various preprocessing strategies, we present a framework which comprises a combination of (1) nonparametric testing including reproducibility and prediction metrics of the data-driven NPAIRS framework (Strother et al.
View Article and Find Full Text PDFBackground And Purpose: Intravenous tissue plasminogen activator for ischemic stroke is approved for eligible patients who can be treated within a 3-hour window, but treatment rates remain disappointingly low, often <5%. To improve rapid access to stroke thrombolysis in Toronto, Canada, a citywide prehospital acute stroke activation protocol was implemented by the provincial government to transport acute stroke patients directly to one of 3 regional stroke centers, bypassing local hospitals. This comprised a paramedic screening tool, ambulance destination decision rule, and formal memorandum of understanding of system stakeholders.
View Article and Find Full Text PDFProspective memory (PM) is the ability to carry out a planned intention at a future time. We studied PM deficits in a group of community-dwelling stroke survivors compared with normal controls. Twelve stroke patients and 12 matched controls performed a series of tests assessing executive function, prospective (PM) and retrospective memory (RM).
View Article and Find Full Text PDFFunctional imaging is beginning to outline the brain's functional architecture and mechanisms of recovery from injury. I will review primarily the motor-function literature from normal populations, learning trials, stroke recovery, and rehabilitation with a neural network approach that may prove fruitful in further advancing our understanding of brain plasticity in response to focal lesions. A key consideration in this review will be how the development of distributed motor networks might constrain recovery as a function of the altered connectivity between damaged and nondamaged areas.
View Article and Find Full Text PDFTop Stroke Rehabil
October 2003
Neurocognitive sequelae of stroke create a significant impact on the patient and frequently disrupt recovery from the physical manifestations. This article strives to review types of neurocognitive changes after stroke and discuss the underlying pathophysiology. Management options are presented for the diverse changes that may be encountered.
View Article and Find Full Text PDFTop Stroke Rehabil
October 2003
Strokes are focal lesions in the brain and as such bring about deficits and portend a course of recovery depending on the nature of the lesion. Given the large number of possible combinations of locations, sizes, and types of lesions, a clear and reliable formula for predicting outcomes based on these characteristics has been statistically difficult, particularly early in the course of recovery. Severity of deficit and age of the patient accounts for sufficient variability that the influence of other factors becomes statistically harder to illustrate.
View Article and Find Full Text PDFThe modern stroke unit is making significant contributions to the care of stroke victims and is proving to be an effective, cost-saving enterprise. The precise factors that contribute to the efficacy of these units have yet to be identified, but a combination of protocolized approaches to patient care, critical paths, a focus of expertise, and heightened index of suspicion for comorbidities all probably play a role. This article outlines the basic features of a modern stroke unit and surveys the literature on stroke unit outcomes.
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