Search results for "Neurophysiology"
showing 10 items of 196 documents
Pain Neurophysiology Education and Therapeutic Exercise for Patients With Chronic Low Back Pain: A Single-Blind Randomized Controlled Trial.
2018
Abstract: Objective To assess the effect of a pain neurophysiology education (PNE) program plus therapeutic exercise (TE) for patients with chronic low back pain (CLBP). Design Single-blind randomized controlled trial. Setting Private clinic and university. Participants Patients with CLBP for ≥6 months (N=56). Interventions Participants were randomized to receive either a TE program consisting of motor control, stretching, and aerobic exercises (n=28) or the same TE program in addition to a PNE program (n=28), conducted in two 30- to 50-minute sessions in groups of 4 to 6 participants. Main Outcomes Measures The primary outcome was pain intensity rated on the numerical pain rating scale whi…
Inter-joint coordination of posture on a seesaw device
2016
Even though specific adjustments of the multi-joint control of posture have been observed when posture is challenged, multi-joint coordination on a seesaw device has never been accurately assessed. The current study was conducted in order to investigate the multi-joint coordination when subjects were standing on either a seesaw device or on a stable surface, with the eyes open or closed. Eighteen healthy active subjects were recruited. A principal component analysis and a Self-Organizing Maps analysis were performed on the joint angles in order to detect and characterize dominant coordination patterns. Intermuscular EMG coherence was analysed in order to assess the neurophysiological mechan…
''Alterations with Movement Duration in the Kinematics of a Whole Body Pointing Movement''
2013
Casteran, Matthieu | Manckoundia, Patrick | Pozzo, Thierry | Thomas, Elizabeth; International audience; ''Our aim was to investigate how the organization of a whole body movement is altered when movement duration (MD) is varied. Subjects performed the same whole body pointing movement over long, normal and short MDs. The kinematic trajectories were then analyzed on a normalized time base. A principal components analysis (PCA) revealed that the degree of coordination between the elevation angles of the body did not change with MD. This lack of significant differences in the coordination was interesting given that small spatial and temporal differences were observed in the individual kinemati…
Object size modulates fronto-parietal activity during reaching movements
2014
In both monkeys and humans, reaching-related sensorimotor transformations involve the activation of a wide fronto-parietal network. Recent neurophysiological evidence suggests that some components of this network host not only neurons encoding the direction of arm reaching movements, but also neurons whose involvement is modulated by the intrinsic features of an object (e.g. size and shape). To date, it has yet to be investigated whether a similar modulation is evident in the human reaching-related areas. To fill this gap, we asked participants to reach towards either a small or a large object while kinematic and electroencephalographic signals were recorded. Behavioral results showed that …
Effects of levodopa oral bolus on the kinematics of the pointing movements in Parkinson's disease patients.
2005
We studied the time-course of a levodopa oral bolus effects on the kinematics of patients affected by a mild akinetic-rigid form of idiopathic Parkinson's disease (PD). Eleven PD patients were evaluated: a) in OFF-state, that is before their first medication or after its withdrawal, b) in ON-state, that is at 1/2, 1, 2, 3, 4, 5, 6, 24, 30 and 48 hours after the administration of 250 mg of levodopa plus 25mg of carbidopa. The main kinematics (i. e.movement time, peak of velocity, peak of acceleration and peak of deceleration) of pointing movements to six target-stimuli placed on the horizontal plane of a table were recorded. Clinical conditions were assessed according to the Motor Examinatio…
The P600-as-P3 hypothesis revisited: single-trial analyses reveal that the late EEG positivity following linguistically deviant material is reaction …
2014
The P600, a late positive ERP component following linguistically deviant stimuli, is commonly seen as indexing structural, high-level processes, e.g. of linguistic (re)analysis. It has also been identified with the P3 (P600-as-P3 hypothesis), which is thought to reflect a systemic neuromodulator release facilitating behavioural shifts and is usually response time aligned. We investigated single-trial alignment of the P600 to response, a critical prediction of the P600-as-P3 hypothesis. Participants heard sentences containing morphosyntactic and semantic violations and responded via a button press. The elicited P600 was perfectly response aligned, while an N400 following semantic deviations …
Modulation of right motor cortex excitability without awareness following presentation of masked self-images.
2004
The neural substrates of self-awareness have been studied with a variety of neurophysiological and behavioral tools. In the present study, unconscious modulation of corticospinal excitability following presentation of self-images was probed with transcranial magnetic stimulation (TMS). TMS-induced motor evoked potentials (MEP) were collected from the contralateral first dorsal interosseus (FDI) muscle while subjects viewed masked pictures of their own face. MEP amplitudes were compared to those obtained when pictures of strangers were masked. Masked self-images induced a relative increase in corticospinal excitability when TMS was applied to the right primary motor cortex. These results dem…
Quantifying changes in EEG complexity induced by photic stimulation.
2009
Summary Objectives: This study aims to characterize EEG complexity, measured as the prediction error resulting from nonlinear prediction, in healthy humans during photic stimulation. Methods: EEGs were recorded from 15 subjects with eyes closed (EC) and eyes open (EO), during the baseline condition and during stroboscopic photic stimulation (PS) at 5, 10, and 15 Hz. The mean squared prediction error (MSPE) resulting from nearest neighbor local linear prediction was taken as complexity index. Complexity maps were generated interpolating the MSPE index over a schematic scalp representation. Results: Statistical analysis revealed that: i) EEG shows good predictability in all conditions and see…
Changes in the probability of firing of motor units following electrical stimulation in human limb muscles
1986
Changes in the probability of motor unit firing was studied in ten different muscles (six muscles in the upper extremity and four muscles in the lower extremity) of eleven healthy human subjects. The responses were elicited by the electrical stimulation of cutaneous or mixed nerves during weak voluntary contraction of the muscle studied, and were recorded by averaging the rectified surface electromyogram. In eight of the ten muscles, well-detectable, short and long latency excitatory phases were observed. The most constant and well-identified excitatory responses were observed in the first interosseus dorsalis muscle in the hand, and in the extensor digitorum brevis muscle in the foot. Thes…
Do Stretch Durations Affect Muscle Mechanical and Neurophysiological Properties?
2016
International audience; The aim of the study was to determine whether stretching durations influence acute changes of mechanical and neurophysiological properties of plantar flexor muscles. Plantar flexors of 10 active males were stretched in passive conditions on an isokinetic dynamometer. Different durations of static stretching were tested in 5 randomly ordered experimental trials (1, 2, 3, 4 and 10×30-s). Fascicle stiffness index, evoked contractile properties and spinal excitability (Hmax/Mmax) were examined before (PRE), immediately after (POST0) and 5 min after (POST5) stretching. No stretch duration effect was recorded for any variable. Moreover, whatever the stretching duration, st…