Search results for "Motor"
showing 10 items of 3137 documents
Effect of focal cerebellar lesions on procedural learning in the serial reaction time task
1998
Prior studies have shown that procedural learning is severely impaired in patients with diffuse cerebellar damage (cortical degeneration) as measured by the serial reaction time task (SRTT). We hypothesize that focal cerebellar lesions can also have lateralized effects on procedural learning. Our objective was to assess the effects of focal cerebellar lesions in procedural learning as measured by the SRTT. We studied 14 patients with single, unilateral vascular lesions in the territory of the posterior-inferior or superior cerebellar artery, who were compared with ten age- and sex-matched controls in a one-handed version of the SRTT. Patients with lesions at any other level of the brain or …
Neck Muscle Vibration and Spatial Orientation During Stepping in Place in Humans
2002
Unilateral long-lasting vibration was applied to the sternomastoid muscle to assess the influence of asymmetric neck proprioceptive input on body orientation during stepping-in-place. Blindfolded subjects performed 3 sequences of 3 trials, each lasting 60 s: control, vibration applied during stepping (VDS), and vibration applied before stepping (VBS). VDS caused clear-cut whole body rotation toward the side opposite to vibration. The body rotated around a vertical axis placed at about arm's length from the body. The rotation did not begin immediately on switching on the vibrator. The delay varied from subject to subject from a few seconds to about 10 s. Once initiated, the angular velocity…
Transcranial direct current stimulation of the motor cortex induces distinct changes in thermal and mechanical sensory percepts
2009
Abstract Objective The aim of this single-blinded, complete crossover study was to evaluate the effects of tDCS on thermal and mechanical perception, as assessed by quantitative sensory testing (QST). Methods QST was performed upon the radial part of both hands of eight healthy subjects (3 female, 5 male, 25–41 years of age). These subjects were examined before and after cathodal, anodal or sham tDCS, applied in a random order. TDCS was administered for 15 min at a 1 mA current intensity, with the active electrode placed over the left primary motor cortex and the reference electrode above the right orbit. Results After cathodal tDCS, cold detection thresholds (CDT), mechanical detection thr…
Effects of alertness management training on sleepiness among long-haul truck drivers : a randomized controlled trial
2018
Education is a frequently recommended remedy for driver sleepiness in occupational settings, although not many studies have examined its usefulness. To date, there are no previous on-road randomized controlled trials investigating the benefits of training on sleepiness among employees working in road transport. To examine the effects of an educational intervention on long-haul truck drivers' sleepiness at the wheel, amount of sleep between work shifts, and use of efficient sleepiness countermeasures (SCM) in association with night and non-night shift, a total of 53 truck drivers operating from southern Finland were allocated into an intervention and a control group using a stratified random…
Sedentary behaviour and sleep problems among 42,489 community-dwelling adults in six low- and middle-income countries
2018
There is a lack of multinational research investigating the association between sleep problems and sedentary behaviour. In this study, we investigated the relationship between the time spent sedentary during waking hours and sleep problems in six low- and middle-income countries. Cross-sectional, community-based data from the Study on Global Ageing and Adult Health survey were analysed. Adjusted logistic regression analyses were undertaken to explore the relationship between self-reported sleep problems (such as difficulties falling asleep, waking up frequently during the night or waking up too early in the morning) in the last 30 days and self-reported sedentary time (categorized as <4,…
Evidence for early activation of primary motor cortex and SMA after electrical lower limb stimulation using EEG source reconstruction
2006
Compared to median nerve somatosensory evoked potentials (SEP), less is known about activity evoked by nerve stimulation of the lower limb. To understand the mechanisms and the physiology of sensor- and motor control it is useful to investigate the sensorimotor functions as revealed by a standardized functional status. Therefore, we investigated SEPs of the lower limb in 6 healthy male volunteers. For each side, tibial and peroneal nerves were stimulated transcutaneously at the fossa poplitea. The tibial nerves were also stimulated further distally at the ankle joint. Source localization was applied to 64-EEG-channel data of the SEPs. In contrast to somatosensory areas, which are activated …
Perceptual-Cognitive Skills and Performance in Orienteering
2008
The goal was analysis of the perceptual-cognitive skills associated with sport performance in orienteering in a sample of 22 elite and 17 nonelite runners. Variables considered were memory, basic orienteering techniques, map reading, symbol knowledge, map-terrain-map identification, and spatial organisation. A computerised questionnaire was developed to measure the variables. The reliability of the test (agreement between experts) was 90%. Findings suggested that competence in performing basic orienteering techniques efficiently was a key variable differentiating between the elite and the nonelite athletes. The results are discussed in comparison with previous studies.
Cardiorespiratory and Neuromuscular Responses to Motocross Riding
2008
The aim of the present study was to examine physiological and neuromuscular responses during motocross riding at individual maximal speed together with the riding-induced changes in maximal isometric force production. Seven A-level (group A) and 5 hobby-class (group H) motocross-riders performed a 30-minute riding test on a motocross track and maximal muscle strength and oxygen uptake (VO2max) tests in a laboratory. During the riding the mean (+/-SD) VO2 reduced in group A from 86 +/- 10% to 69 +/- 6% of the maximum (P < 0.001), whereas in group H the corresponding reduction was from 94 +/- 25% to 82 +/- 20% (P < 0.05). This relative VO2 during the riding correlated with riding speed (r = 0…
An ensemble analysis of electromyographic activity during whole body pointing with the use of support vector machines.
2011
Import JabRef | WosArea Life Sciences and Biomedicine - Other Topics; International audience; We explored the use of support vector machines (SVM) in order to analyze the ensemble activities of 24 postural and focal muscles recorded during a whole body pointing task. Because of the large number of variables involved in motor control studies, such multivariate methods have much to offer over the standard univariate techniques that are currently employed in the field to detect modifications. The SVM was used to uncover the principle differences underlying several variations of the task. Five variants of the task were used. An unconstrained reaching, two constrained at the focal level and two …
Somatotopic arrangement of sudomotor axon reflex sweating in humans
2005
Impaired sweating may be one of the first symptoms in neuropathies, and therefore the evaluation of sweating might facilitate their early detection. Sudomotor axon reflexes can be quantified by two different methods: quantitative sudomotor axon reflex testing (QSART) measures the amount of local sweating, whereas staining with the iodine starch reaction assesses the extension of the sudomotor axon reflex area. The aim of our study was to compare both tests at three different sites on the leg: foot, lower leg and thigh.QSART and iodine starch staining after iontophoretic stimulation with acetylcholine were performed on 15 male volunteers (mean age: 25; range 24-27 years) on the left resp. th…