scholarly journals Reaction to a Visual Stimulus: Anticipation with Steady and Dynamic Contractions

2019 ◽  
Vol 69 (1) ◽  
pp. 17-27
Author(s):  
Agostina Casamento-Moran ◽  
Stefan Delmas ◽  
Seoung Hoon Park ◽  
Basma Yacoubi ◽  
Evangelos A. Christou

Abstract Reacting fast to visual stimuli is important for many activities of daily living and sports. It remains unknown whether the strategy used during the anticipatory period influences the speed of the reaction. The purpose of this study was to determine if reaction time (RT) differs following a steady and a dynamic anticipatory strategy. Twenty‐two young adults (21.0 ± 2.2 yrs, 13 women) participated in this study. Participants performed 15 trials of a reaction time task with ankle dorsiflexion using a steady (steady force at 15% MVC) and a dynamic (oscillating force from 10‐20% MVC) anticipatory strategy. We recorded primary agonist muscle (tibialis anterior; TA) electromyographic (EMG) activity. We quantified RT as the time interval from the onset of the stimulus to the onset of force. We found that a dynamic anticipatory strategy, compared to the steady anticipatory strategy, resulted in a longer RT (p = 0.04). We classified trials of the dynamic condition based on the level and direction of anticipatory force at the moment of the response. We found that RT was longer during the middle descending relative to the middle ascending and the steady conditions (p < 0.01). All together, these results suggest that RT is longer when preceded by a dynamic anticipatory strategy. Specifically, the longer RT is a consequence of the variable direction of force at which the response can occur, which challenges the motor planning process.

2018 ◽  
Vol 120 (4) ◽  
pp. 2059-2065
Author(s):  
Stefan Delmas ◽  
Agostina Casamento-Moran ◽  
Seoung Hoon Park ◽  
Basma Yacoubi ◽  
Evangelos A. Christou

Reaction time (RT) is the time interval between the appearance of a stimulus and initiation of a motor response. Within RT, two processes occur, selection of motor goals and motor planning. An unresolved question is whether perturbation to the motor planning component of RT slows the response and alters the voluntary activation of muscle. The purpose of this study was to determine how the modulation of muscle activity during an RT response changes with motor plan perturbation. Twenty-four young adults (20.5 ±1.1 yr, 13 women) performed 15 trials of an isometric RT task with ankle dorsiflexion using a sinusoidal anticipatory strategy (10–20% maximum voluntary contraction). We compared the processing part of the RT and modulation of muscle activity from 10 to 60 Hz of the tibialis anterior (primary agonist) when the stimulus appeared at the trough or at the peak of the sinusoidal task. We found that RT ( P = 0.003) was longer when the stimulus occurred at the peak compared with the trough. During the time of the reaction, the electromyography (EMG) power from 10 to 35 Hz was less at the peak than the trough ( P = 0.019), whereas the EMG power from 35 to 60 Hz was similar between the peak and trough ( P = 0.92). These results suggest that perturbation to motor planning lengthens the processing part of RT and alters the voluntary activation of the muscle by decreasing the relative amount of power from 10 to 35 Hz. NEW & NOTEWORTHY We aimed to determine whether perturbation to motor planning would alter the speed and muscle activity of the response. We compared trials when a stimulus appeared at the peak or trough of an oscillatory reaction time task. When the stimulus occurred at the trough, participants responded faster, with greater force, and less EMG power from 10-35 Hz. We provide evidence that motor planning perturbation slows the response and alters the voluntary activity of the muscle.


2011 ◽  
Vol 105 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Bernardo Perfetti ◽  
Clara Moisello ◽  
Eric C. Landsness ◽  
Svetlana Kvint ◽  
April Pruski ◽  
...  

In this study, we characterized the patterns and timing of cortical activation of visually guided movements in a task with critical temporal demands. In particular, we investigated the neural correlates of motor planning and on-line adjustments of reaching movements in a choice-reaction time task. High-density electroencephalograohy (EEG, 256 electrodes) was recorded in 13 subjects performing reaching movements. The topography of the movement-related spectral perturbation was established across five 250-ms temporal windows (from prestimulus to postmovement) and five frequency bands (from theta to beta). Nine regions of interest were then identified on the scalp, and their activity was correlated with specific behavioral outcomes reflecting motor planning and on-line adjustments. Phase coherence analysis was performed between selected sites. We found that motor planning and on-line adjustments share similar topography in a fronto-parietal network, involving mostly low frequency bands. In addition, activities in the high and low frequency ranges have differential function in the modulation of attention with the former reflecting the prestimulus, top-down processes needed to promote timely responses, and the latter the planning and control of sensory-motor processes.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Do-Young Kwon ◽  
Byung Kyu Park ◽  
Ji Won Kim ◽  
Gwang-Moon Eom ◽  
Junghwa Hong ◽  
...  

Evaluation of motor symptoms in Parkinson’s disease (PD) is still based on clinical rating scales by clinicians. Reaction time (RT) is the time interval between a specific stimulus and the start of muscle response. The aim of this study was to identify the characteristics of RT responses in PD patients using electromyography (EMG) and to elucidate the relationship between RT and clinical features of PD. The EMG activity of 31 PD patients was recorded during isometric muscle contraction. RT was defined as the time latency between an auditory beep and responsive EMG activity. PD patients demonstrated significant delays in both initiation and termination of muscle contraction compared with controls. Cardinal motor symptoms of PD were closely correlated with RT. RT was longer in more-affected side and in more-advanced PD stages. Frontal cognitive function, which is indicative of motor programming and movement regulation and perseveration, was also closely related with RT. In conclusion, greater RT is the characteristic motor features of PD and it could be used as a sensitive tool for motor function assessment in PD patients. Further investigations are required to clarify the clinical impact of the RT on the activity of daily living of patients with PD.


1991 ◽  
Vol 65 (6) ◽  
pp. 1542-1553 ◽  
Author(s):  
M. Matsumura ◽  
T. Sawaguchi ◽  
T. Oishi ◽  
K. Ueki ◽  
K. Kubota

1. The role of intracortical GABAergic inhibition in the performance of hand movements was studied in macaque monkeys while they performed two behavioral tasks: a raisin pick-up test and a visual reaction-time task. A gamma-aminobutyric acid (GABA) agonist, muscimol (MUS; 1-5 microgram), and an antagonist, bicuculline methiodide (BMI, 1-10 micrograms), were injected at various sites in the precentral motor cortex (MC), at which single-unit activity was related to the manual aspects of the performance of the reaction-time task. 2. Manual dexterity in the raisin pick-up task was severely disturbed by injections of either MUS or BMI into the hand MC. The effect was less severe after injections into the postarcuate premotor cortex (PM). 3. Performance of the reaction-time task was unstable after injection of BMI. The instability was caused by increased electromyogram (EMG) activity and by cocontractions of agonistic and antagonistic muscles of the arm during the pressing or release of the lever. 4. Reaction time was increased by injection of MUS, although the effect was temporary and decayed within 60 min. These deficits were consistent with the time course of the decrease in the total amount of EMG activity of hand muscles related to the task. As in the case of the raisin pick-up task, performance deficits were greater when MUS and BMI were injected into the hand MC and smaller when they were injected into the PM. 5. After injection of BMI, the animals gradually began to display muscle activity in response to a green warning signal that did not require a behavioral response. The muscle activity accelerated to spontaneous muscle twitches without any external stimulus, and the animals were unable to continue the task. These BMI-induced twitches were eliminated by injection of barbiturate. 6. Appropriate levels of GABAergic inhibition in the MC appear, therefore, to be important for the regulation of spatiotemporally organized ensembles of muscle activity, in particular for reciprocal contraction at the task-related joints.


F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 323
Author(s):  
Nouf Al Backer ◽  
Koloud Ateeq Alharbi ◽  
Abdulrahman Alfahadi ◽  
Syed Shahid Habib ◽  
Shahid Bashir

Background: The neuropsychological tests and its subtests are composed of the motor planning task; simple reaction time task and the intradimensional/extradimensional shift (IED) task from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were developed to examine specific components of cognition. The main objective of this study was to examine the reliability of these CANTAB subtests in pediatric patients with learning disabilities (LD) in Saudi Arabia. Methods: We administered the CANTAB subset test to 92 participants with LD and 68 controls with no LD. The tests performed were motor planning task (MOT), simple reaction time task (SRT) and the intradimensional/extradimensional shift (IED). Results: There was no significant age difference between the case and the control group (case: 9.2 ± 2.4 years versus controls: 9.0 ± 1.6 years, p=0.544). The IED and MOT were significantly longer among patients with LD versus control (p <0.001). LD cases had a longer SRT time than controls (cases: 1050.4 ± 626.5 versus controls: 815.5 ± 133.9, p=0.003). LD patients completed an average of 3.0 stages, than the controls, who were able to complete a mean of 8.4 IED stages (p<0.001). SRT was significantly longer in the case group (965.9 ± 716.4) compared to the controls (747.7 ± 120.7, p=0.014). LD cases made more errors in the motor screening tasks (MOT-Error) compared to the control group (case: 14.6 ± 4.5 versus controls: 12.4 ± 2.7, p<0.001). Conclusion: Patients with LD have poor CANTAB subtest results. If these CANTAB subtests do measure cognitive function, this adds to the accumulating evidence of cognitive impairment association in LD, and such studies should remain an active area of research.


2018 ◽  
Vol 18 (1) ◽  
pp. 167-175 ◽  
Author(s):  
Andrés Molero-Chamizo ◽  
José R. Alameda Bailén ◽  
Tamara Garrido Béjar ◽  
Macarena García López ◽  
Inmaculada Jaén Rodríguez ◽  
...  

1979 ◽  
Vol 49 (3) ◽  
pp. 979-987 ◽  
Author(s):  
M. Granjon ◽  
C. A. Possamaï ◽  
G. Reynard ◽  
D. Oberti

In reaction time tasks, where the moment of occurrence of the response signal is uncertain, the temporal constraints of preparatory processes imply that subjects distribute their preparation during the preparatory period. The notion of cost of preparation has been proposed to explain the time course of these processes. This experiment was run to determine the effect of the cost of preparation on a serial-RT task and on a RT task where a rest interval of various possible durations (3, 6, or 9 sec.) is introduced. 12 subjects were tested. Data show that the amount spent on preparation during a trial affects the subject's performance during the next trials. But an hypothesis about memory search must also be advanced to explain the effect of the rest interval on the relationship of RT and the current preparatory period.


F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 323
Author(s):  
Nouf Al Backer ◽  
Koloud Ateeq Alharbi ◽  
Abdulrahman Alfahadi ◽  
Syed Shahid Habib ◽  
Shahid Bashir

Background: The neuropsychological tests and its subtests are composed of the motor planning task; simple reaction time task and the intradimensional/extradimensional shift (IED) task from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were developed to examine specific components of cognition. The main objective of this study was to examine the reliability of these CANTAB subtests in pediatric patients with learning disabilities (LD) in Saudi Arabia. Methods: We administered the CANTAB subset test to 92 participants with LD and 68 controls with no LD. The tests performed were motor planning task (MOT), simple reaction time task (SRT) and the intradimensional/extradimensional shift (IED). Results: There was no significant age difference between the case and the control group (case: 9.2 ± 2.4 years versus controls: 9.0 ± 1.6 years, p=0.544). The IED and MOT were significantly longer among patients with LD versus control (p <0.001). LD cases had a longer SRT time than controls (cases: 1050.4 ± 626.5 versus controls: 815.5 ± 133.9, p=0.003). LD patients completed an average of 3.0 stages, than the controls, who were able to complete a mean of 8.4 IED stages (p<0.001). SRT was significantly longer in the case group (965.9 ± 716.4) compared to the controls (747.7 ± 120.7, p=0.014). LD cases made more errors in the motor screening tasks (MOT-Error) compared to the control group (case: 14.6 ± 4.5 versus controls: 12.4 ± 2.7, p<0.001). Conclusion: Patients with LD have poor CANTAB subtest results. If these CANTAB subtests do measure cognitive function, this adds to the accumulating evidence of cognitive impairment association in LD, and such studies should remain an active area of research.


GeroPsych ◽  
2011 ◽  
Vol 24 (4) ◽  
pp. 169-176 ◽  
Author(s):  
Philippe Rast ◽  
Daniel Zimprich

In order to model within-person (WP) variance in a reaction time task, we applied a mixed location scale model using 335 participants from the second wave of the Zurich Longitudinal Study on Cognitive Aging. The age of the respondents and the performance in another reaction time task were used to explain individual differences in the WP variance. To account for larger variances due to slower reaction times, we also used the average of the predicted individual reaction time (RT) as a predictor for the WP variability. Here, the WP variability was a function of the mean. At the same time, older participants were more variable and those with better performance in another RT task were more consistent in their responses.


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