Author
Mark Hallett
Other affiliations: Government of the United States of America, Armed Forces Institute of Pathology, University Hospital of Lausanne ...read more
Bio: Mark Hallett is an academic researcher from National Institutes of Health. The author has contributed to research in topics: Transcranial magnetic stimulation & Motor cortex. The author has an hindex of 186, co-authored 1170 publications receiving 123741 citations. Previous affiliations of Mark Hallett include Government of the United States of America & Armed Forces Institute of Pathology.
Papers published on a yearly basis
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TL;DR: The posturographic protocol has the potential to be a useful tool for evaluating severity and nature of postural instability and the effects of pharmacologic and rehabilitative treatment and results indicate that combining direct body measurements with force-plate data has the Potential to expose the underlying impairments that cause disequilibrium.
129 citations
TL;DR: Effective combinations of computational methods provide possible classification of human movement intention from single trial EEG with reasonable accuracy and could be the basis for a potential brain-computer interface based on human natural movement, which might reduce the requirement of long-term training.
129 citations
TL;DR: These findings may suggest that ERD is compatible with both corticospinal activation and inhibition, ERS indicating the removal of either, resulting in cortical idling.
129 citations
TL;DR: Findings support the involvement of the primary motor area as well as the premotor area in motor ideation.
Abstract: Although motor performance may be enhanced through mental practice, the neurophysiological substrate of mental stimulation (ideation) of a motor task is not well established. We used blood oxygen level-dependent contrast echo planar imaging at 1.5 T to identify regions of increased neural activity during the performance and ideation of a motor task. Five subjects performed a sequential finger-to-thumb opposition task and also imagined themselves performing the task in the absence of actual muscle movement. In all subjects, the left primary sensorimotor cortex showed more activation with actual movement than with motor ideation, but two subjects had significant activation with motor ideation. The left premotor area showed comparable activation with both actual and imagined performance in three subjects. These findings support the involvement of the primary motor area as well as the premotor area in motor ideation. © 1995 Wiley-Liss, Inc.
128 citations
TL;DR: Findings from both human and animal studies of functional brain alterations underlying changes in sensorimotor circuits associated with motor learning and memory, leading to such a disabling motor disorder are focused on.
Abstract: Understanding of the pathophysiology of dystonia derives primarily from studies of focal dystonias. Physiological investigations have revealed a number of abnormalities that may reflect the genetic substrate that predisposes certain individuals to develop dystonia. There is a loss of inhibition in the central nervous system, and a loss of surround inhibition specifically. Plasticity is increased, and there are sensory abnormalities. Which of these disorders is primary is uncertain.
128 citations
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9,362 citations
TL;DR: Past observations are synthesized to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment, and for understanding mental disorders including autism, schizophrenia, and Alzheimer's disease.
Abstract: Thirty years of brain imaging research has converged to define the brain’s default network—a novel and only recently appreciated brain system that participates in internal modes of cognition Here we synthesize past observations to provide strong evidence that the default network is a specific, anatomically defined brain system preferentially active when individuals are not focused on the external environment Analysis of connectional anatomy in the monkey supports the presence of an interconnected brain system Providing insight into function, the default network is active when individuals are engaged in internally focused tasks including autobiographical memory retrieval, envisioning the future, and conceiving the perspectives of others Probing the functional anatomy of the network in detail reveals that it is best understood as multiple interacting subsystems The medial temporal lobe subsystem provides information from prior experiences in the form of memories and associations that are the building blocks of mental simulation The medial prefrontal subsystem facilitates the flexible use of this information during the construction of self-relevant mental simulations These two subsystems converge on important nodes of integration including the posterior cingulate cortex The implications of these functional and anatomical observations are discussed in relation to possible adaptive roles of the default network for using past experiences to plan for the future, navigate social interactions, and maximize the utility of moments when we are not otherwise engaged by the external world We conclude by discussing the relevance of the default network for understanding mental disorders including autism, schizophrenia, and Alzheimer’s disease
8,448 citations
TL;DR: The basal ganglia serve primarily to integrate diverse inputs from the entire cerebral cortex and to "funnel" these influences, via the ventrolateral thalamus, to the motor cortex.
Abstract: Information about the basal ganglia has accumulated at a prodigious pace over the past decade, necessitating major revisions in our concepts of the structural and functional organization of these nuclei. From earlier data it had appeared that the basal ganglia served primarily to integrate diverse inputs from the entire cerebral cortex and to "funnel" these influences, via the ventrolateral thalamus, to the motor cortex (Allen & Tsukahara 1974, Evarts & Thach 1969, Kemp & Powell 1971). In particular, the basal
8,111 citations
TL;DR: FieldTrip is an open source software package that is implemented as a MATLAB toolbox and includes a complete set of consistent and user-friendly high-level functions that allow experimental neuroscientists to analyze experimental data.
Abstract: This paper describes FieldTrip, an open source software package that we developed for the analysis of MEG, EEG, and other electrophysiological data. The software is implemented as a MATLAB toolbox and includes a complete set of consistent and user-friendly high-level functions that allow experimental neuroscientists to analyze experimental data. It includes algorithms for simple and advanced analysis, such as time-frequency analysis using multitapers, source reconstruction using dipoles, distributed sources and beamformers, connectivity analysis, and nonparametric statistical permutation tests at the channel and source level. The implementation as toolbox allows the user to perform elaborate and structured analyses of large data sets using the MATLAB command line and batch scripting. Furthermore, users and developers can easily extend the functionality and implement new algorithms. The modular design facilitates the reuse in other software packages.
7,963 citations
TL;DR: The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or her own research.
Abstract: I have developed "tennis elbow" from lugging this book around the past four weeks, but it is worth the pain, the effort, and the aspirin. It is also worth the (relatively speaking) bargain price. Including appendixes, this book contains 894 pages of text. The entire panorama of the neural sciences is surveyed and examined, and it is comprehensive in its scope, from genomes to social behaviors. The editors explicitly state that the book is designed as "an introductory text for students of biology, behavior, and medicine," but it is hard to imagine any audience, interested in any fragment of neuroscience at any level of sophistication, that would not enjoy this book. The editors have done a masterful job of weaving together the biologic, the behavioral, and the clinical sciences into a single tapestry in which everyone from the molecular biologist to the practicing psychiatrist can find and appreciate his or
7,563 citations