47 research outputs found
Motor action execution in reaction-time movements : Magnetoencephalographic study
No full textOBJECTIVE:
Reaction-time movements are internally planned in the brain. Presumably, proactive control in reaction-time movements appears as an inhibitory phase preceding movement execution. We identified the brain activity of reaction-time movements in close proximity to movement onset and compared it with similar self-paced voluntary movements without external command.
DESIGN:
We recorded 18 healthy participants performing reaction-time and self-paced fast index finger abductions with 306-sensor magnetoencephalography and electromyography. Reaction-time movements were performed as responses to cutaneous electrical stimulation delivered on the hand radial nerve area. Motor field and movement-evoked field 1 corresponding to the sensorimotor cortex activity during motor execution and afferent feedback after the movement were analyzed with Brainstorm's scouts using regions of interest analysis.
RESULTS:
Primary motor and somato sensory cortices were active before and after movement onset. During reaction-time movements, primary motor and somato sensory cortices showed higher activation compared with self-paced movements. In primary motor cortex, stronger preparatory activity was seen in self-paced than in reaction time task.
CONCLUSIONS:
Both primary motor and somato sensory cortices participated in the movement execution and in the prediction of sensory consequences of movement. Cutaneous stimulation facilitated cortical activation during motor field after reaction-time movements, implying the applicability of cutaneous stimulation in motor rehabilitation.peerReviewe
Cerebral sources of electrical potentials related to human vocalization and mouth movement
No full textMultiple Dipole Source Models for Scalp-Recorded Event-Related Potentials: Example from Complex Visual Processing in the Human Brain
No full text2000 Mathematics Subject Classification: 62P10, 92C20Electrical activity of the human brain can be recorded on the scalp. One of the advantages of the electrical recordings is the high temporal resolution by which e.g. cognitive processes can be followed from millisecond to millisecond. It is not uncommon to record simultaneously 128 electrode sites with high sampling rate and thus advanced mathematical and statistical methods
are needed to sufficiently process the obtained data. Here an example of the analysis of the data recorded during a complex visual processing task is presented. Using advanced methods large amounts of data can be reduced and new information of the function of the human brain can be investigated
Short and long latency reflexes in human muscles following electrical and mechanical stimulation
No full textA review of international clinical guidelines for rehabilitation of people with neurological conditions: what recommendations are made for upper limb assessment?
No full textBackground: upper limb impairment is a common problem for people with neurological disabilities, affecting activity, performance, quality of life and independence. Accurate, timely assessments are required for effective rehabilitation, and development of novel interventions. International consensus on upper limb assessment is needed to make research findings be more meaningful, provide a benchmark for quality in clinical practice, more cost-effective neurorehabilitation and improved outcomes for neurological patients undergoing rehabilitation.Aim: to conduct a systematic review, as part of the output of a European COST Action, to identify what recommendations aremade for upper limb assessment.Methods: we systematically reviewed published guidance on measures and protocols for assessing upper limb function inneurological rehabilitation via electronic databases from January 2007 – December 2017. Additional records were then identified through other sources. Records were selected for inclusion based on scanning of titles, abstracts and full text by two authors working independently, and a third author if there was disagreement. Records were included if they referred to ‘rehabilitation’ and ‘assessment’ or ‘measurement’. Reasons for exclusion were documented.Results: From the initial 552 records identified (after duplicates were removed), 34 satisfied our criteria for inclusion and only six recommended specific outcome measures and /or protocols. Records were divided into National Guidelines and other practice guidelines published in peer reviewed journals. There was agreement that assessment is critical, should be conducted early and at regular intervals and that there is a need for standardised measures. Assessments should be conducted by a healthcare professional trained in using the measure and should encompass body function and structure, activity and participation.Conclusions: we present a comprehensive, critical and original summary of current recommendations. Defining a core set of measures and agreed protocols requires international consensus between experts representing the diverse and multi-disciplinary field of neurorehabilitation including clinical researchers and practitioners, rehabilitation technology researchers and commercial developers. Current lack of guidance may hold-back progress in understanding function and recovery. Together with a Delphi consensus study and an overview of systematic reviews of outcome measures it will contribute to the development of international guidelines for upper limb assessment in neurological conditions
Long-term physical activity modifies automatic visual processing
No full textElectrophysiologically registered visual mismatch negativity (vMMN) is known to represent automatic visual processing in human visual cortex. Since physical activity (PA) is generally beneficial to cerebrovascular function, we wanted to find out if automatic visual processing is affected by PA. We investigated the connection between long-term leisure-time PA and precognitive visual processing in 32 healthy young males. Participants were divided into active (n = 16) and inactive (n = 16) group according to their leisure-time PA records from the past three years. vMMN was recorded with electroencephalogram using passive oddball paradigm with visual bars. Standard (90%) and deviant (10%) stimuli in different orientations were presented randomly while participant’s attention was directed to an audio play. No visual task was involved. vMMN difference waveforms were generated and peak latencies and signal integrals were determined in post-stimulus window of 100–300 ms. vMMN latencies were shorter in active participants compared to inactive ones in the occipital cortex. A trend towards larger integral values in occipital area in active participants was observed, albeit non-significant. Physically active participants showed faster automatic processing of deviant stimuli compared to inactive ones in the occipital area. This may imply enhanced early non-attended visual processing in those individuals who are habitually physically active.peerReviewe
European evidence-based recommendations for clinical assessment of upper limb in neurorehabilitation (CAULIN): data synthesis from systematic reviews, clinical practice guidelines and expert consensus: data synthesis from systematic reviews, clinical practice guidelines and expert consensus
No full textPublisher Copyright: © 2021, The Author(s).Background: Technology-supported rehabilitation can help alleviate the increasing need for cost-effective rehabilitation of neurological conditions, but use in clinical practice remains limited. Agreement on a core set of reliable, valid and accessible outcome measures to assess rehabilitation outcomes is needed to generate strong evidence about effectiveness of rehabilitation approaches, including technologies. This paper collates and synthesizes a core set from multiple sources; combining existing evidence, clinical practice guidelines and expert consensus into European recommendations for Clinical Assessment of Upper Limb In Neurorehabilitation (CAULIN). Methods: Data from systematic reviews, clinical practice guidelines and expert consensus (Delphi methodology) were systematically extracted and synthesized using strength of evidence rating criteria, in addition to recommendations on assessment procedures. Three sets were defined: a core set: strong evidence for validity, reliability, responsiveness and clinical utility AND recommended by at least two sources; an extended set: strong evidence OR recommended by at least two sources and a supplementary set: some evidence OR recommended by at least one of the sources. Results: In total, 12 measures (with primary focus on stroke) were included, encompassing body function and activity level of the International Classification of Functioning and Health. The core set recommended for clinical practice and research: Fugl-Meyer Assessment of Upper Extremity (FMA-UE) and Action Research Arm Test (ARAT); the extended set recommended for clinical practice and/or clinical research: kinematic measures, Box and Block Test (BBT), Chedoke Arm Hand Activity Inventory (CAHAI), Wolf Motor Function Test (WMFT), Nine Hole Peg Test (NHPT) and ABILHAND; the supplementary set recommended for research or specific occasions: Motricity Index (MI); Chedoke-McMaster Stroke Assessment (CMSA), Stroke Rehabilitation Assessment Movement (STREAM), Frenchay Arm Test (FAT), Motor Assessment Scale (MAS) and body-worn movement sensors. Assessments should be conducted at pre-defined regular intervals by trained personnel. Global measures should be applied within 24 h of hospital admission and upper limb specific measures within 1 week. Conclusions: The CAULIN recommendations for outcome measures and assessment procedures provide a clear, simple, evidence-based three-level structure for upper limb assessment in neurological rehabilitation. Widespread adoption and sustained use will improve quality of clinical practice and facilitate meta-analysis, critical for the advancement of technology-supported neurorehabilitation.Peer reviewe
Electric source localization adds evidence for task-specific CNVs
No full textThis study was an attempt to replicate recent magnetoencephalographic (MEG) findings on human task-specific CNV sources (Basile et al., Electroencephalography and Clinical Neurophysiology 90, 1994, 157-165) by means of a spatio-temporal electric source localization method (Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 62, 1985, 32-44; Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 65, 1986, 344-360; Scherg and Berg, Brain Electric Source Analysis Handbook, Version 2). The previous MEG results showed CNV sources in the prefrontal cortex of the two hemispheres for two tasks used, namely visual pattern recognition and visual spatial recognition tasks. In the right hemisphere, the sources were more anterior and inferior for the spatial recognition task than for the pattern recognition task. In the present study we obtained CNVs in five subjects during two tasks identical to the MEG study. The elicited electric potentials were modeled with four spatio-temporal dipoles for each task, three of which accounted for the visual evoked response and one that accounted for the CNV. For all subjects the dipole explaining the CNV was always localized in the frontal region of the head, however, the dipole obtained during the visual spatial recognition task was more anterior than the one obtained during the pattern recognition task. Thus, task-specific CNV sources were again observed, although the stable model consisted of only one dipole located close to the midline instead of one dipole in each hemisphere. This was a major difference in the CNV sources between the previous MEG and the present electric source analysis results. We discuss the possible basis for the difference between the two methods used to study slow brain activity that is believed to originate from extended cortical patches
Electric Source Localization Adds Evidence for Task-Specific CNVs
No full textThis study was an attempt to replicate recent magnetoencephalographic (MEG) findings on human task-specific CNV sources (Basile et al., Electroencephalography and Clinical Neurophysiology 90, 1994, 157–165) by means of a spatio-temporal electric source localization method (Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 62, 1985, 32–44; Scherg and von Cramon, Electroencephalography and Clinical Neurophysiology 65, 1986, 344-360; Scherg and Berg, Brain Electric Source Analysis Handbook, Version 2). The previous MEG results showed CNV sources in the prefrontal cortex of the two hemispheres for two tasks used, namely visual pattern recognition and visual spatial recognition tasks. In the right hemisphere, the sources were more anterior and inferior for the spatial recognition task than for the pattern recognition task. In the present study we obtained CNVs in five subjects during two tasks identical to the MEG study. The elicited electric potentials were modeled with four spatio-temporal dipoles for each task, three of which accounted for the visual evoked response and one that accounted for the CNV. For all subjects the dipole explaining the CNV was always localized in the frontal region of the head, however, the dipole obtained during the visual spatial recognition task was more anterior than the one obtained during the pattern recognition task. Thus, task-specific CNV sources were again observed, although the stable model consisted of only one dipole located close to the midline instead of one dipole in each hemisphere. This was a major difference in the CNV sources between the previous MEG and the present electric source analysis results. We discuss the possible basis for the difference between the two methods used to study slow brain activity that is believed to originate from extended cortical patches
