Search results for "REF"
showing 10 items of 8690 documents
Eye-Hand Coordination in Rhythmical Pointing
2009
International audience; The authors investigated the relation between hand kinematics and eye movements in 2 variants of a rhythmical Fitts's task in which eye movements were necessary or not necessary. P. M. Fitts's (1954) law held in both conditions with similar slope and marginal differences in hand-kinematic patterns and movement continuity. Movement continuity and eye-hand synchronization were more directly related to movement time than to task index of difficulty. When movement time was decreased to fewer than 350 ms, eye-hand synchronization switched from continuous monitoring to intermittent control. The 1:1 frequency ratio with stable pi/6 relative phase changed for 1:3 and 1:5 fre…
Motion sickness induced by otolith stimulation is correlated with otolith-induced eye movements
2008
International audience; This article addresses the relationships between motion sickness (MS) and three-dimensional (3D) ocular responses during otolith stimulation. A group of 19 healthy subjects was tested for motion sickness during a 16 min otolith stimulation induced by off-vertical axis rotation (OVAR) (constant velocity 60 degrees /s, frequency 0.16 Hz). For each subject, the MS induced during the session was quantified, and based on this quantification, the subjects were divided into two groups of less susceptible (MS-), and more susceptible (MS+) subjects. The angular eye velocity induced by the otolith stimulation was analyzed in order to identify a possible correlation between sus…
Famous face recognition and naming test: a normative study.
2003
Tests of famous face recognition and naming, and tasks assessing semantic knowledge about famous people after presentation either of their faces or their names are often used in the neuropsychological examination of aphasic, amnesic and demented patients. A total of 187 normal subjects took part in this study. The aim was to collect normative data for a newly devised test including five subtests: famous face naming, fame judgement after face presentation and after name presentation, semantic knowledge about famous people after face presentation and after name presentation. Norms were calculated taking into account demographic variables such as age, sex and education and adjusted scores were…
Changes of electrically elicited reflexes in hand and forearm muscles in man.
1987
Cutaneo-muscular reflexes with short and long latency excitatory phases following digital nerve stimulation were observed in the first dorsal interosseus muscle of the hand in healthy subjects. The short latency reflex was obtained also with the H-reflex method in the flexor carpi radialis muscle, stimulating the median nerve, with a mean latency (+/- SE) of 15.4 +/- 0.5 ms. The height of the subject correlated with the H-reflex latency. The amplitudes of maximal M-response and maximal H-reflex were higher in athletes than in normals. During weak voluntary contraction of the muscle studied the 50% H-reflex amplitude increased and during passive stretching of wrist flexors the resting amplit…
Automatic algorithm for monitoring systolic pressure variation and difference in pulse pressure.
2009
BACKGROUND: Difference in pulse pressure (dPP) reliably predicts fluid responsiveness in patients. We have developed a respiratory variation (RV) monitoring device (RV monitor), which continuously records both airway pressure and arterial blood pressure (ABP). We compared the RV monitor measurements with manual dPP measurements. METHODS: ABP and airway pressure (PAW) from 24 patients were recorded. Data were fed to the RV monitor to calculate dPP and systolic pressure variation in two different ways: (a) considering both ABP and PAW (RV algorithm) and (b) ABP only (RV(slim) algorithm). Additionally, ABP and PAW were recorded intraoperatively in 10-min intervals for later calculation of dPP …
No evidence for attenuated stress-induced extrastriatal dopamine signaling in psychotic disorder
2015
AbstractStress is an important risk factor in the etiology of psychotic disorder. Preclinical work has shown that stress primarily increases dopamine (DA) transmission in the frontal cortex. Given that DA-mediated hypofrontality is hypothesized to be a cardinal feature of psychotic disorder, stress-related extrastriatal DA release may be altered in psychotic disorder. Here we quantified for the first time stress-induced extrastriatal DA release and the spatial extent of extrastriatal DA release in individuals with non-affective psychotic disorder (NAPD). Twelve healthy volunteers (HV) and 12 matched drug-free NAPD patients underwent a single infusion [18F]fallypride positron emission tomogr…
Net influx of plasma 6-[18F]fluoro-L-DOPA (FDOPA) to the ventral striatum correlates with prefrontal processing of affective stimuli.
2006
Dopaminergic neurotransmission in the ventral and dorsal striatum interact with central processing of rewarding and reward-indicating stimuli, and may affect frontocortical-striatal-thalamic circuits regulating goal-directed behaviour. Thirteen healthy male volunteers were investigated with multimodal imaging, using the radioligand 6-[ 18 F]fluoro-L-DOPA (FDOPA) for positron emission tomography (PET) measurements of dopamine synthesis capacity, and also functional magnetic resonance imaging (fMRI) in a cognitive activation paradigm. We calculated the correlation between FDOPA net blood-brain influx (K app in ; ml/g/min) in the ventral and associative dorsal striatum and BOLD signal changes …
Sensory-specific satiety for a food is unaffected by the ad libitum intake of other foods during a meal. Is SSS subject to dishabituation?
2012
Sensory-specific satiety (SSS) is defined as a decrease in the pleasantness of a specific food that has just been eaten to satiation, while other non-eaten foods remain pleasant. The objectives of this study were the following: (1) to investigate whether SSS for a food is affected by the ad libitum intake of other foods presented sequentially during a meal, (2) to compare the development of SSS when foods are presented simultaneously or sequentially during a meal, and (3) to examine whether SSS is modified when foods are presented in an unusual order within a meal. Twelve participants participated in three tasting sessions. In session A, SSS for protein-, fat- and carbohydrate-rich sandwich…
Foot Strike Pattern, Step Rate, and Trunk Posture Combined Gait Modifications to Reduce Impact Loading during Running
2019
Elevated impact loading can be detrimental to runners as it has been linked to the increased risk of tibial stress fracture and plantar fasciitis. The objective of this study was to investigate the combined effects of foot strike pattern, step rate, and anterior trunk lean gait modifications on impact loading in runners. Nineteen healthy runners performed 12 separate gait modification trials involving: three foot strike patterns (rearfoot, midfoot, and forefoot strike), two step rates (natural and 10% increased), and two anterior trunk lean postures (natural and 10-degree increased flexion). Overall, forefoot strike combined with increased step rate led to the lowest impact loading rates, a…
Structural hemispheric asymmetries underlie verbal Stroop performance
2017
Performance on tasks involving cognitive control such as the Stroop task is often associated with left lateralized brain activations. Based on this neuro-functional evidence, we tested whether leftward structural grey matter asymmetries would also predict inter-individual differences in combatting Stroop interference. To check for the specificity of the results, both a verbal Stroop task and a spatial one were administered to a total of 111 healthy young individuals, for whom T1-weighted magnetic resonance imaging (MRI) images were also acquired. Surface thickness and area estimations were calculated using FreeSurfer. Participants' hemispheres were registered to a symmetric template and Lat…