Selective Inhibition of Movement

2007 ◽  
Vol 97 (3) ◽  
pp. 2480-2489 ◽  
Author(s):  
James P. Coxon ◽  
Cathy M. Stinear ◽  
Winston D. Byblow
Keyword(s):  
Task Performance ◽  
Selective Inhibition ◽  
Selective Excitation ◽  
Motor Output ◽  
Cortical Representation ◽  
Inhibitory Pathway ◽  
Fixed Target ◽  
Bimanual Task ◽  
Neural Inhibition ◽  
Left And Right

In studies of volitional inhibition, successful task performance usually requires the prevention of all movement. In reality, movements are selectively prevented in the presence of global motor output. The aim of this study was to investigate the ability to prevent one movement while concurrently executing another, referred to as selective inhibition. In two experiments, participants released switches with either their index and middle fingers (unimanual) or their left and right index fingers (bimanual) to stop two moving indicators at a fixed target (Go trials). Stop trials occurred when either one or both indicators automatically stopped before reaching the target, signaling that prevention of the prepared movement was required. Stop All and selective Stop trials were randomly interspersed among more frequently occurring Go trials. We found that selective inhibition is harder to perform than nonselective inhibition, for both unimanual and bimanual task contexts. During selective inhibition trials, lift time of the responding digit was delayed in both experiments by ≤100 ms, demonstrating the generality of the result. A nonselective neural inhibitory pathway may temporarily “brake” the required response, followed by selective excitation of the to-be-moved digit's cortical representation. After selective inhibition trials, there were persistent asynchronies between finger lift times of subsequent Go trials. The persistent effects reflect the behavioral consequences of nonspecific neural inhibition combined with selective neural disinhibition.

scholarly journals Gender-Dependent Bimanual Task Performance

Medicina ◽  
2011 ◽  
Vol 47 (9) ◽  
pp. 73
Author(s):  
Dalia Mickevičienė ◽  
Kristina Motiejūnaitė ◽  
Diana Karanauskienė ◽  
Albertas Skurvydas ◽  
Daiva Vizbaraitė ◽  
...  
Keyword(s):  
Reaction Time ◽  
Task Performance ◽  
Target Location ◽  
Maximal Velocity ◽  
Men And Women ◽  
Left Hand ◽  
Bimanual Task ◽  
Significant Difference ◽  
Left And Right ◽  
Speed Accuracy

Background and Objective. Many studies have suggested that each hand has a different special talent; however, there is a lack of data in the area of goal-directed bimanual hand coordination and its dependence on gender. The aim of this paper was to investigate gender-dependent bimanual speed-accuracy task performance. Material and Methods. Twelve healthy young males and twelve healthy young females (all righthanded) performed protractile movements with both arms simultaneously by pushing joysticks toward two targets as quickly and accurately as possible. Results. Though no significant difference was observed in the reaction time during a unimanual speed-accuracy task between the left and right hands as well as men and women, during a bimanual task, the reaction time of both the hands was significantly longer in women than men. There was no significant difference in the velocity of both the hands during a bimanual speed-accuracy task between men and women, while the accuracy of the left hand was significantly greater in men than women. There was no significant difference in intraindividual variability in the reaction time, maximal velocity, and path of movement between men and women as well as the left and right hands, but variability in the average velocity of the right hand both in women and men was significantly greater compared with their left hand. Conclusions. Whereas people typically look at the target location for a reaching movement, it is possible that two objects are simultaneously fixated.

Experiments on the central pattern generator for swimming in amphibian embryos

1982 ◽  
Vol 296 (1081) ◽  
pp. 229-243 ◽  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Pattern Generator ◽  
Pattern Generation ◽  
Motor Output ◽  
Cycle Period ◽  
Sensory Stimuli ◽  
Swimming Pattern ◽  
Left And Right

The central nervous system of paralysed Xenopus laevis embryos can generate a motor output pattern suitable for swimming locomotion. By recording motor root activity in paralysed embryos with transected nervous systems we have shown that: (a) the spinal cord is capable of swimming pattern generation; (b) swimming pattern generator capability in the hindbrain and spinal cord is distributed; (c) caudal hindbrain is necessary for sustained swimming output after discrete stimulation. By recording similarly from embryos whose central nervous system was divided longitudinally into left and right sides, we have shown that: (a) each side can generate rhythmic motor output with cycle periods like those in swimming; (b) during this activity cycle period increases within an episode, and there is the usual rostrocaudal delay found in swimming; (c) this activity is influenced by sensory stimuli in the same way as swimming activity; ( d) normal phase coupling of the left and right sides can be established by the ventral commissure in the spinal cord. We conclude that interactions between the antagonistic (left and right) motor systems are not necessary for swimming rhythm generation and present a model for swimming pattern generation where autonomous rhythm generators on each side of the nervous system drive the motoneurons. Alternation is achieved by reciprocal inhibition, and activity is initiated and maintained by tonic excitation from the hindbrain.

scholarly journals High variability impairs motor learning regardless of whether it affects task performance

2018 ◽  
Vol 119 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Marco Cardis ◽  
Maura Casadio ◽  
Rajiv Ranganathan
Keyword(s):  
Motor Learning ◽  
Task Performance ◽  
Null Space ◽  
Motor Task ◽  
Task Space ◽  
Movement Variability ◽  
Motor Variability ◽  
Different Dimensions ◽  
Left And Right

Motor variability plays an important role in motor learning, although the exact mechanisms of how variability affects learning are not well understood. Recent evidence suggests that motor variability may have different effects on learning in redundant tasks, depending on whether it is present in the task space (where it affects task performance) or in the null space (where it has no effect on task performance). We examined the effect of directly introducing null and task space variability using a manipulandum during the learning of a motor task. Participants learned a bimanual shuffleboard task for 2 days, where their goal was to slide a virtual puck as close as possible toward a target. Critically, the distance traveled by the puck was determined by the sum of the left- and right-hand velocities, which meant that there was redundancy in the task. Participants were divided into five groups, based on both the dimension in which the variability was introduced and the amount of variability that was introduced during training. Results showed that although all groups were able to reduce error with practice, learning was affected more by the amount of variability introduced rather than the dimension in which variability was introduced. Specifically, groups with higher movement variability during practice showed larger errors at the end of practice compared with groups that had low variability during learning. These results suggest that although introducing variability can increase exploration of new solutions, this may adversely affect the ability to retain the learned solution.NEW & NOTEWORTHY We examined the role of introducing variability during motor learning in a redundant task. The presence of redundancy allows variability to be introduced in different dimensions: the task space (where it affects task performance) or the null space (where it does not affect task performance). We found that introducing variability affected learning adversely, but the amount of variability was more critical than the dimension in which variability was introduced.

Cortical Representation of Swallowing: A Modified Dual Task Paradigm

2002 ◽  
Vol 94 (3) ◽  
pp. 1029-1040 ◽  
Author(s):  
Stephanie K. Daniels ◽  
David M. Corey ◽  
Cristen L. Barnes ◽  
Nikki M. Faucheaux ◽  
Daniel H. Priestly ◽  
...  
Keyword(s):  
Dual Task ◽  
Right Hemisphere ◽  
Index Finger ◽  
Finger Tapping ◽  
Left Index Finger ◽  
Cortical Representation ◽  
Word Repetition ◽  
Dual Task Paradigm ◽  
Left And Right ◽  
The Right

It is unclear whether the cortical representation of swallowing is lateralized to the left cerebral hemisphere, right hemisphere, or bilaterally represented. As dysphagia is common in acute stroke, it is important to elucidate swallowing lateralization to facilitate earlier detection of stroke patients who may be at greater risk for dysphagia and aspiration. In this study, a modified dual task paradigm was designed to study laterality of swallowing in a group of 14 healthy, young, right-handed, male adults. The subjects were studied at baseline and with interference. Baseline conditions, performed separately, were continuous swallowing, finger tapping using the right and left index fingers, and word repetition. Interference tasks, including tapping with the right index finger, tapping with the left index finger, and word repetition, were completed with and without swallowing. Finger-tapping rate was measured, and x-ray samples of the swallowing task were taped to measure swallowing rate and volume swallowed. At baseline, the rate of tapping the right index finger was significantly faster than that of the left index finger. There was a significant decline in the tapping rates of both left and right index fingers with swallowing interference. The volume per swallow was significantly reduced during the interfering language task of silent repetition. These results offer partial support for a bilateral representation of swallowing as well as suggest an important left hemispheric contribution to swallowing. However, it cannot be concluded that the left hemisphere is more important than the right, as a comparable right hemisphere task was not studied.

Changes in functional coupling patterns during bimanual task performance

Neuroreport ◽  
2004 ◽  
Vol 15 (9) ◽  
pp. 1387-1390 ◽  
Author(s):  
Deborah J. Serrien ◽  
Peter Brown
Keyword(s):  
Task Performance ◽  
Functional Coupling ◽  
Bimanual Task

Force coordination during bimanual task performance in Parkinson’s disease

2013 ◽  
Vol 229 (2) ◽  
pp. 261-271 ◽  
Author(s):  
Stacey L. Gorniak ◽  
Andre G. Machado ◽  
Jay L. Alberts
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Task Performance ◽  
Force Coordination ◽  
Bimanual Task

scholarly journals Motor variability prior to learning is a poor predictor of the ability to adopt new movement solutions

2020 ◽  
Author(s):  
Rajiv Ranganathan ◽  
Marco Lin ◽  
Samuel Carey ◽  
Rakshith Lokesh ◽  
Mei-Hua Lee ◽  
...  
Keyword(s):  
Individual Differences ◽  
Motor Learning ◽  
Task Performance ◽  
Task Context ◽  
Motor Variability ◽  
Poor Predictor ◽  
Potential Marker ◽  
Baseline Task ◽  
Left And Right ◽  
Highly Correlated

AbstractMany contexts in motor learning require a learner to change from an existing movement solution to a novel movement solution to perform the same task. Recent evidence has pointed to motor variability prior to learning as a potential marker for predicting individual differences in motor learning. However, it is not known if this variability is predictive of the ability to adopt a new movement solution for the same task. Here, we examined this question in the context of a redundant precision task requiring control of motor variability. Fifty young adults learned a precision task that involved throwing a virtual puck toward a target using both hands. Because the speed of the puck depended on the sum of speeds of both hands, this task could be achieved using multiple solutions. Participants initially performed a baseline task where there was no constraint on the movement solution, and then performed a novel task where they were constrained to adopt a specific movement solution requiring asymmetric left and right hand speeds. Results showed that participants were able to learn the new solution, and this change was associated with changes in both the amount and structure of variability. However, individual differences in baseline motor variability were only weakly correlated with initial and final task performance when using the new solution, with greater variability being associated with higher errors. We also found a strong specificity component – initial variability when using the new solution was highly correlated with final task performance with the new solution, but once again, higher variability was associated with greater errors. These results suggest that motor variability is not necessarily indicative of flexibility and highlight the need to consider the task context in determining the relation between motor variability and learning.

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