Search results for " performance."
showing 10 items of 2429 documents
Prism adaptation by mental practice
2012
International audience; The prediction of our actions and their interaction with the external environment is critical for sensorimotor adaptation. For instance, during prism exposure, which deviates laterally our visual field, we progressively correct movement errors by combining sensory feedback with forward model sensory predictions. However, very often we project our actions to the external environment without physically interacting with it (e.g., mental actions). An intriguing question is whether adaptation will occur if we imagine, instead of executing, an arm movement while wearing prisms. Here, we investigated prism adaptation during mental actions. In the first experiment, participa…
COMT genotype predicts BOLD signal and noise characteristics in prefrontal circuits.
2006
Abstract Objective: Prefrontal dopamine (DA) is catabolized by the COMT (catechol- O -methyltransferase) enzyme. Literature suggests that the Val/Met single nucleotide polymorphism (SNP) in the COMT gene predicts executive cognition in humans with Val carriers showing poorer performance due to less available synaptic DA. Recent fMRI studies are thought to agree with these studies having demonstrated prefrontal hyperactivation during n -back and attention-requiring tasks. This was interpreted as “less efficient” processing due to impaired signal-to-noise ratio (SNR) of neuronal activity. However, electrophysiological studies of neuronal SNR in primates and humans imply that prefrontal cortex…
Encoding of faces and objects into visual working memory: an event-related brain potential study.
2013
Visual working memory (VWM) is an important prerequisite for cognitive functions, but little is known on whether the general perceptual processing advantage for faces also applies to VWM processes. The aim of the present study was (a) to test whether there is a general advantage for face stimuli in VWM and (b) to unravel whether this advantage is related to early sensory processing stages. To address these questions, we compared encoding of faces and complex nonfacial objects into VWM within a combined behavioral and event-related brain potential (ERP) study. In detail, we tested whether the N170 ERP component - which is associated with face-specific holistic processing - is affected by mem…
Voluntary activation and mechanical performance of human triceps surae muscle after exhaustive stretch-shortening cycle jumping exercise.
2003
The purpose of this study was to examine neuromuscular factors that may contribute to post exercise force loss and subsequent recovery after exhaustive stretch-shortening cycle (SSC) exercise. Six subjects were fatigued on a sledge apparatus by 100 maximal rebound jumps followed by continuous submaximal jumping until complete exhaustion. Exercise-induced changes in neuromuscular performance were followed up to 7 days post exercise. The total number of jumps in the SSC exercise ranged from 336 to 1392. The SSC exercise induced a significant immediate plantarflexion torque decline of 29, 38 and 44% (P<0.05) in maximal voluntary contraction and evoked maximal twitch and low-frequency (LF) stim…
The relationship between age and fitness profiles in elite male ice hockey players
2021
Background: The present study investigated relationships between age, body composition and performance in elite male ice hockey players.Methods: 199 players performed off-ice tests (countermovement jump height (CMJ) and body composition) and on-ice tests (5-10-5 Pro Agility test, 30-m sprint test and the maximal Yo-Yo Intermittent Recovery Ice Hockey test (Yo-Yo IR1-IHMAX) for assessment of aerobic capacity.Results: No overall correlations between age and performance were present except small-moderate positive associations between age and body-and muscle mass (r=0.24-0.30, ≤0.05). The youngest age group (YOU; 18-21 years) were 4-9% lighter than all other age groups and possessed 7% less mus…
Patterned functional network disruption in amyotrophic lateral sclerosis
2019
Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease primarily affecting motor function, with additional evidence of extensive nonmotor involvement. Despite increasing recognition of the disease as a multisystem network disorder characterised by impaired connectivity, the precise neuroelectric characteristics of impaired cortical communication remain to be fully elucidated. Here, we characterise changes in functional connectivity using beamformer source analysis on resting‐state electroencephalography recordings from 74 ALS patients and 47 age‐matched healthy controls. Spatiospectral characteristics of network changes in the ALS patient group were quantifi…
Conflicts in language processing: A new perspective on the N400-P600 distinction
2011
Conflicts in language processing often correlate with late positive event-related brain potentials (ERPs), particularly when they are induced by inconsistencies between different information types (e.g. syntactic and thematic/plausibility information). However, under certain circumstances, similar sentence-level interpretation conflicts (inanimate subjects) engender negativity effects (N400s) instead. The present ERP study was designed to shed light on this inconsistency. In previous studies showing monophasic positivities (P600s), the conflict was irresolvable and induced via a verb. whereas N400s were elicited by resolvable, argument-induced conflicts. Here, we therefore examined irresolv…
Addition of a second opioid may improve opioid response in cancer pain: preliminary data
2004
Recent experimental data suggest a possible use of an opioid combination to improve analgesia. In cancer patients, a rapid opioid escalation due to either worsening of the pain condition or the development of tolerance is a critical phase, as this condition is associated with a negative prognosis. The aim of this study was to assess the effects of adding a second opioid at low doses in patients with a poor analgesic benefit after dose escalation. Fourteen patients receiving strong opioids who had increased their dosage more than 100% in the last week unsuccessfully were randomly chosen to add a second opioid to the first using an initial equivalent dosage of 20% of the previous therapy. The…
Effect of mental fatigue on speed–accuracy trade-off
2015
International audience; The aim of this study was to investigate the effects of mental fatigue on the duration of actual and imagined goal-directed arm movements involving speed-accuracy trade-off. Ten participants performed actual and imagined point-to-point arm movements as accurately and as fast as possible, before and after a 90-min sustained cognitive task inducing mental fatigue, and before and after viewing a neutral control task (documentary movie) that did not induce mental fatigue. Target width and center-to-center target distance were varied, resulting in five different indexes of difficulty. Prior to mental fatigue, actual and imagined movement duration increased with the diffic…
Alpha-amylase serum levels in professional soccer players are not related with physical fitness.
2017
Backgorund Recent evidence has showed that serum or salivary values of α-amylase predict endurance running performance. In this study we investigate whether serum α-amylase concentration may be associated with training status during a competitive season and after a detraining period in professional soccer players. Methods The study population consisted in 15 male professional soccer players from an Italian major league team (age [mean±SD] 27±5 years, weight 76.9±4.1 kg, height 1.82±0.05 m). Serum α-amylase levels were measured 3 times during the last part of a competitive season (January, March and May) and just before preseason training (July). Results Metabolic and cardiovascular fitness …