scholarly journals Physical or Cognitive Exertion Does Not Influence Cortical Movement Preparation for Rapid Arm Movements

Motor Control ◽  
2020 ◽  
Vol 24 (4) ◽  
pp. 473-498
Author(s):  
Stijn Schouppe ◽  
Jessica Van Oosterwijck ◽  
Jan R. Wiersema ◽  
Stefaan Van Damme ◽  
Tine Willems ◽  
...  
Keyword(s):  
Physical Exertion ◽  
Arm Movement ◽  
Time On Task ◽  
Movement Preparation ◽  
Experimental Conditions ◽  
Healthy Humans ◽  
Task Effects ◽  
Single Bout ◽  
Rapid Arm Movements ◽  
Central Factors

The contribution of central factors to movement preparation (e.g., the contingent negative variation [CNV]) and the influence of fatigue on such factors are still unclear, even though executive cognitive functions are regarded as key elements in motor control. Therefore, this study examined CNV amplitude with electroencephalography in 22 healthy humans during a rapid arm movement task prior to and following three experimental conditions: (a) a no exertion/control condition, (b) a physical exertion, and (c) a cognitive exertion. CNV amplitude was affected neither by a single bout of physical/cognitive exertion nor by the control condition. Furthermore, no time-on-task effects of the rapid arm movement task on the CNV were found. Exertion did not affect cortical movement preparation, which is in contrast to previous findings regarding time-on-task effects of exertion on CNV. Based on the current findings, the rapid arm movement task is deemed suitable to measure cortical movement preparation, without being affected by learning effects and physical/cognitive exertion.

scholarly journals Kinetics and Topology of DNA Associated with Circulating Extracellular Vesicles Released during Exercise

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 522
Author(s):  
Elmo W. I. Neuberger ◽  
Barlo Hillen ◽  
Katharina Mayr ◽  
Perikles Simon ◽  
Eva-Maria Krämer-Albers ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Size Exclusion ◽  
Affinity Capture ◽  
Healthy Humans ◽  
Dnase Digestion ◽  
And Topology ◽  
Single Bout ◽  
Exclusion Chromatography ◽  
Free Circulating Dna ◽  
Line Elements

Although it is widely accepted that cancer-derived extracellular vesicles (EVs) carry DNA cargo, the association of cell-free circulating DNA (cfDNA) and EVs in plasma of healthy humans remains elusive. Using a physiological exercise model, where EVs and cfDNA are synchronously released, we aimed to characterize the kinetics and localization of DNA associated with EVs. EVs were separated from human plasma using size exclusion chromatography or immuno-affinity capture for CD9+, CD63+, and CD81+ EVs. DNA was quantified with an ultra-sensitive qPCR assay targeting repetitive LINE elements, with or without DNase digestion. This model shows that a minute part of circulating cell-free DNA is associated with EVs. During rest and following exercise, only 0.12% of the total cfDNA occurs in association with CD9+/CD63+/CD81+EVs. DNase digestion experiments indicate that the largest part of EV associated DNA is sensitive to DNase digestion and only ~20% are protected within the lumen of the separated EVs. A single bout of running or cycling exercise increases the levels of EVs, cfDNA, and EV-associated DNA. While EV surface DNA is increasing, DNAse-resistant DNA remains at resting levels, indicating that EVs released during exercise (ExerVs) do not contain DNA. Consequently, DNA is largely associated with the outer surface of circulating EVs. ExerVs recruit cfDNA to their corona, but do not carry DNA in their lumen.

Time of day, time of sleep, and time on task effects on sleepiness and cognitive performance of bus drivers

2022 ◽  
Author(s):  
Maryam Maghsoudipour ◽  
Ramin Moradi ◽  
Sara Moghimi ◽  
Sonia Ancoli-Israel ◽  
Pamela N. DeYoung ◽  
...  
Keyword(s):  
Cognitive Performance ◽  
Time Of Day ◽  
Time On Task ◽  
Bus Drivers ◽  
Task Effects

The perceptual acquisition of Thai phonology by English speakers: task and stimulus effects

2003 ◽  
Vol 19 (3) ◽  
pp. 209-223 ◽  
Author(s):  
Joe Pater
Keyword(s):  
Voice Onset Time ◽  
Onset Time ◽  
Acoustic Properties ◽  
Experimental Conditions ◽  
Lexical Representations ◽  
Place Of Articulation ◽  
Task Effects ◽  
Stimulus Effects ◽  
Parallel Effect ◽  
Native Speakers Of English

This article presents a follow-up to Curtin et al.’s study of the perceptual acquisition of Thai laryngeal contrasts by native speakers of English, which found that subjects performed better on contrasts in voice than aspiration. This finding - surprising in light of earlier cross-linguistic voice onset time (VOT) research - was attributed to the fact that the task tapped lexical representations, which are unspecified for aspiration according to standard assumptions in generative phonology. The present study further investigated possible task effects by examining the discrimination and categorization of the same stimuli in various experimental conditions. Stimulus effects were also investigated by performing token-based analyses of the results, and by comparing them to acoustic properties of the tokens. The outcome of the discrimination experiment was the opposite of the earlier study, with significantly better performance on contrasts in aspiration than voice, even on a lexical task. A second finding of this experiment is that place of articulation interacts with the perception of the laryngeal distinctions; the aspiration distinction is discriminated better on the labials, and voice on alveolars. A parallel effect of place of articulation was also found in a categorization experiment.

Do time-on-task effects reveal face specificity in object cognition?

2020 ◽  
Vol 32 (4) ◽  
pp. 423-441
Author(s):  
Dominik-Borna Ćepulić ◽  
Florian Schmitz ◽  
Andrea Hildebrandt
Keyword(s):  
Time On Task ◽  
Task Effects ◽  
Object Cognition

Attenuation of postexertional hypotension by cardiac afferent blockade

1993 ◽  
Vol 265 (4) ◽  
pp. H1179-H1183 ◽  
Author(s):  
H. L. Collins ◽  
S. E. DiCarlo
Keyword(s):  
Treadmill Exercise ◽  
Inhibitory Influence ◽  
Arterial Baroreflex ◽  
Experimental Conditions ◽  
Descending Aorta ◽  
Spontaneously Hypertensive ◽  
Single Bout ◽  
Teflon Catheter ◽  
Cardiac Afferents ◽  
Hypotensive Response

Naloxone eliminates postexertional hypotension (PEH) in human and animal models. The effect of naloxone on sympathetic activity during hemorrhage and generation of arterial baroreflex function curves can be stimulated by blockade of cardiac afferent receptors. We tested the hypothesis that cardiac afferent blockade would eliminate PEH in eight spontaneously hypertensive rats (SHR). Rats were instrumented with a Silastic-tipped catheter inserted into the pericardial space. Four weeks later, a Teflon catheter was placed in the descending aorta via the left common carotid artery for measurement of mean arterial pressure (MAP) and heart rate (HR). MAP and HR were examined before (preexercise) and after (postexercise) a single bout of dynamic treadmill exercise (9-12.0 m/min, 10-18% grade for 30-40 min) under three experimental conditions: control, cardiac efferent blockade, and combined cardiac efferent and afferent blockade. MAP significantly decreased (29 +/- 5 and 25.6 +/- 4 mmHg) in the control and cardiac efferent blockade conditions after exercise. However, when cardiac afferents were blocked, the hypotensive response to mild dynamic exercise was significantly attenuated (-6 +/- 3 mmHg). Thus blockade of cardiac afferents eliminated PEH in the SHR. These data suggest that inhibitory influence of cardiac afferents on the circulation may be enhanced after exercise.

scholarly journals Effects of Different Dispositions of Resistance Exercises on Subjective Perception of Effort, Discomfort and Affectivity in Older Women

2019 ◽  
Vol 21 (4) ◽  
pp. 404
Author(s):  
Alex Silva Ribeiro ◽  
Cristiane Afonso ◽  
Matheus Amarante do Nascimento ◽  
Márcio Rogério Oliveira ◽  
Denilson Castro Teixeira
Keyword(s):  
Older Women ◽  
Plantar Flexion ◽  
Affective Response ◽  
Physical Exertion ◽  
Subjective Perception ◽  
Experimental Conditions ◽  
Randomized Design ◽  
Significant Difference ◽  
Resistance Exercises ◽  
Minute Interval

AbstractThe purpose of the study was to verify the effect of two dispositions of resistance exercises on rate of perceived of effort (RPE), discomfort and affectivity in older women. Twenty older women (68.0±6.6 years, 69.8±12.7 kg, and 155.9±7.0 cm) performed in a balanced and randomized design two experimental conditions, namely: a circuit (CIRC) fashion and another in a traditional (TRAD) fashion. In both conditions, six resistance exercises in the following order were performed: push press with kettlebell, swing with kettlebell, plantar flexion, squatting, ladder displacement and shoulder flexion with naval rope, with the same load and three sets of 15 repetitions/exercise. In the CIRC condition, the exercises were performed in stations, with no interval among them, and at the end of the last exercise, a three-minute interval was performed. For the TRAD condition the exercises were performed in consecutive sets, with intervals of 90s between the sets and the exercises. After 15 min of the closure of each session, the RPE (OMNI), feeling (Hardy and Rejeski) and a discomfort scale were applied. There was no significant difference (P>0.05) among  the sessions for PSE (TRAD = 6.0±1.2 vs. CIRC = 6.1±0.9), feeling (TRAD = 3.7±1.6 vs. CIRC = 3.6±1.2) and discomfort (TRAD = 5.2±1.4 vs. CIRC = 5.1±1.3). The results suggest that PSE, discomfort and affective response to resistance exercises are similar when performed in CIRC or TRAD in older women. Keywords: Exercise. Aging. Physical exertion. ResumoO objetivo do estudo foi verificar o efeito de duas diferentes disposições de execução de exercícios resistidos sobre a percepção subjetiva de esforço (PSE), o desconforto e a afetividade em mulheres idosas. Vinte mulheres idosas (68,0±6,6 anos, 69,8±12,7 kg e 155,9±7,0 cm) foram distribuídas de forma balanceada e aleatorizada para duas condições experimentais: disposição de circuito (CIRC) e disposição tradicional (TRAD). Em ambas as condições, seis exercícios resistidos foram executados na seguinte ordem: push press com kettlebell, swing com kettlebell, flexão plantar, agachamento, deslocamento em escada e flexão de ombros com corda naval, com mesma carga e três séries de 15 repetições/exercício. Na condição CIRC os exercícios foram executados em forma de estações, sem intervalo entre os exercícios e, ao final de cada série foi concedido intervalo de três minutos. Para condição TRAD os exercícios foram executados em séries consecutivas, com intervalos de 90s entre os exercícios e as séries. Após 15 min do termino de cada sessão foram aplicadas as escalas de PSE (OMNI), sentimento (Hardy e Rejeski) e desconforto. Não ocorreram diferenças significativas (P>0,05) entre as sessões para PSE (TRAD = 6,0±1,2 vs CIRC = 6,1±0,9), sentimento (TRAD = 3,7±1,6 vs CIRC = 3,6±1,2) e desconforto (TRAD = 5,2±1,4 vs CIRC = 5,1±1,3). Os resultados sugerem que a PSE, o desconforto e a resposta afetiva aos exercícios resistidos são semelhantes quando realizados em CIRC ou TRAD em mulheres idosas. Palavras-chave: Exercício Físico. Envelhecimento. Esforço Físico.

scholarly journals Monitoring Brain State and Behavioral Performance during Repetitive Visual Stimulation

2021 ◽  
Vol 11 (23) ◽  
pp. 11544
Author(s):  
Alexander K. Kuc ◽  
Semen A. Kurkin ◽  
Vladimir A. Maksimenko ◽  
Alexander N. Pisarchik ◽  
Alexander E. Hramov
Keyword(s):  
Visual Stimulation ◽  
Brain Activity ◽  
Decision Time ◽  
Task Demands ◽  
Brain State ◽  
Time On Task ◽  
Behavioral Performance ◽  
Task Effects ◽  
Perceptual Performance ◽  
Eeg Power

We tested whether changes in prestimulus neural activity predict behavioral performance (decision time and errors) during a prolonged visual task. The task was to classify ambiguous stimuli—Necker cubes; manipulating the degree of ambiguity from low ambiguity (LA) to high ambiguity (HA) changed the task difficulty. First, we assumed that the observer’s state changes over time, which leads to a change in the prestimulus brain activity. Second, we supposed that the prestimulus state produces a different effect on behavioral performance depending on the task demands. Monitoring behavioral responses, we revealed that the observer’s decision time decreased for both LA and HA stimuli during the task performance. The number of perceptual errors lowered for HA, but not for LA stimuli. EEG analysis revealed an increase in the prestimulus 9–11 Hz EEG power with task time. Finally, we found associations between the behavioral and neural estimates. The prestimulus EEG power negatively correlated with the decision time for LA stimuli and the erroneous responses rate for HA stimuli. The obtained results confirm that monitoring prestimulus EEG power enables predicting perceptual performance on the behavioral level. The observed different time-on-task effects on the LA and HA stimuli processing may shed light on the features of ambiguous perception.

Sensorimotor representations for pointing to targets in three-dimensional space

1989 ◽  
Vol 62 (2) ◽  
pp. 582-594 ◽  
Author(s):  
J. F. Soechting ◽  
M. Flanders
Keyword(s):  
Target Location ◽  
Dimensional Space ◽  
Visual Representation ◽  
Three Dimensional ◽  
Arm Movement ◽  
Experimental Conditions ◽  
Extrapersonal Space ◽  
Target Locations ◽  
Sensorimotor Representations ◽  
Three Dimensional Space

1. The accuracy with which subjects pointed to targets in extrapersonal space was assessed under a variety of experimental conditions. 2. When subjects pointed in the dark to remembered target locations, they made substantial errors. Errors in distance, measured from the shoulder to the target, were sometimes as much as 15 cm. Errors in direction, also measured from the shoulder, were smaller. 3. An analysis of the information transmitted by the location of the subject's finger about the location of the target showed that the information about the target's distance was consistently lower than the information about its direction. 4. The errors in distance persisted when subjects had their arm in view and pointed in the light to remembered target locations. 5. The errors were much smaller when subjects used a pointer to point to the target or when they were asked to reproduce the position of their finger after it had been passively moved to the target. 6. From these findings we conclude that subjects have a reasonably accurate visual representation of target location and are able to effectively use kinesthetically derived information about target location. We therefore suggest that errors in pointing result from errors in the sensorimotor transformation from the visual representation of the target location to the kinematic representation of the arm movement.

EXPRESS: Visually Guided Movement with Increasing Time-on-Task: Differential Effects on Movement Preparation and Movement Execution

2021 ◽  
pp. 174702182110480
Author(s):  
Andras Matuz ◽  
Dimitri Van der Linden ◽  
Andras N Zsido ◽  
Arpad Csatho
Keyword(s):  
Movement Time ◽  
Time On Task ◽  
Movement Preparation ◽  
Visually Guided ◽  
Movement Execution ◽  
Pointing Movement ◽  
Movement Error ◽  
Phasic Alertness ◽  
Error Ratio ◽  
Variable Movement

Top-down cognitive control seems to be sensitive to the detrimental effects of fatigue induced by time-on-task (ToT). The planning and preparation of the motor responses may be especially vulnerable to ToT. Yet, effects of ToT specific to the different phases of movements have received little attention. Therefore, in three experiments, we assessed the effect of ToT on a mouse-pointing task. In Experiment 1, there were 16 possible target positions with variable movement directions. In Experiment 2, the layout of the targets was simplified. In Experiment 3, using cuing conditions we examined whether the effects of ToT on movement preparation and execution were caused by an increased orientation deficit or decreased phasic alertness. In each experiment, initiation of movement (preparatory phase) became slower, movement execution became faster and overall response time remained constant with increasing ToT. There was, however, no significant within-person association between the preparatory and execution phases. In Experiments 1 and 2, we found a decreasing movement time/movement error ratio, suggesting a more impulsive execution of the pointing movement. In addition, ToT was also accompanied with imprecise movement execution as indicated by the increased errors, mainly in Experiment 2. The results of Experiment 3 indicated that ToT did not induce orientation and phasic alerting deficits but rather was accompanied by decreased tonic alertness.

Sign in / Sign up

Export Citation Format

Share Document