scholarly journals Creative Motor Actions As Emerging from Movement Variability

2017 ◽  
Vol 8 ◽  
Author(s):  
Dominic Orth ◽  
John van der Kamp ◽  
Daniel Memmert ◽  
Geert J. P. Savelsbergh
Keyword(s):  
Movement Variability ◽  
Motor Actions

Space, objects, and motor actions

2006 ◽  
Author(s):  
Michael E. J. Masson ◽  
Daniel N. Bub
Keyword(s):  
Space Objects ◽  
Motor Actions

scholarly journals The Influence of Functional Flywheel Resistance Training on Movement Variability and Movement Velocity in Elite Rugby Players

2020 ◽  
Vol 11 ◽  
Author(s):  
Bruno Fernández-Valdés ◽  
Jaime Sampaio ◽  
Juliana Exel ◽  
Jacob González ◽  
Julio Tous-Fajardo ◽  
...  
Keyword(s):  
Resistance Training ◽  
Movement Variability ◽  
Movement Velocity ◽  
Rugby Players

scholarly journals Free will and neurosurgical resections of the supplementary motor area: a critical review

2021 ◽  
Vol 163 (5) ◽  
pp. 1229-1237 ◽  
Author(s):  
Rickard L Sjöberg
Keyword(s):  
Executive Function ◽  
Free Will ◽  
Corticospinal Tract ◽  
Supplementary Motor Area ◽  
Personal Responsibility ◽  
Motor Area ◽  
Simple Motor ◽  
Motor Actions ◽  
Intense Debate

Abstract Background Research suggests that unconscious activity in the supplementary motor area (SMA) precedes not only certain simple motor actions but also the point at which we become aware of our intention to perform such actions. The extent to which these findings have implications for our understanding of the concepts of free will and personal responsibility has been subject of intense debate during the latest four decades. Methods This research is discussed in relation to effects of neurosurgical removal of the SMA in a narrative review. Results Removal of the SMA typically causes a transient inability to perform non-stimulus-driven, voluntary actions. This condition, known as the SMA syndrome, does not appear to be associated with a loss of sense of volition but with a profound disruption of executive function/cognitive control. Conclusions The role of the SMA may be to serve as a gateway between the corticospinal tract and systems for executive function. Such systems are typically seen as tools for conscious decisions. What is known about effects of SMA resections would thus seem to suggest a view that is compatible with concepts of personal responsibility. However, the philosophical question whether free will exists cannot be definitely resolved on the basis of these observations.

scholarly journals Expression of FoxP2 in the basal ganglia regulates vocal motor sequences in the adult songbird

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lei Xiao ◽  
Devin P. Merullo ◽  
Therese M. I. Koch ◽  
Mou Cao ◽  
Marissa Co ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Basal Ganglia ◽  
Dopamine Receptor ◽  
Speech Disorders ◽  
Receptor Expression ◽  
Vocal Development ◽  
Motor Actions

AbstractDisruption of the transcription factor FoxP2, which is enriched in the basal ganglia, impairs vocal development in humans and songbirds. The basal ganglia are important for the selection and sequencing of motor actions, but the circuit mechanisms governing accurate sequencing of learned vocalizations are unknown. Here, we show that expression of FoxP2 in the basal ganglia is vital for the fluent initiation and termination of birdsong, as well as the maintenance of song syllable sequencing in adulthood. Knockdown of FoxP2 imbalances dopamine receptor expression across striatal direct-like and indirect-like pathways, suggesting a role of dopaminergic signaling in regulating vocal motor sequencing. Confirming this prediction, we show that phasic dopamine activation, and not inhibition, during singing drives repetition of song syllables, thus also impairing fluent initiation and termination of birdsong. These findings demonstrate discrete circuit origins for the dysfluent repetition of vocal elements in songbirds, with implications for speech disorders.

Gait kinematics in Low Back Pain: A non-linear approach

2021 ◽  
pp. 1-8
Author(s):  
Christos Tsigkanos ◽  
Theano Demestiha ◽  
Chara Spiliopoulou ◽  
Georgios Tsigkanos
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Healthy Subjects ◽  
Infrared Camera ◽  
Low Back ◽  
Movement Variability ◽  
Optoelectronic System ◽  
Mean Values ◽  
Non Linear ◽  
Healthy Participants

BACKGROUND: Kinematic analysis has been a dominant tool for addressing the neuromuscular and proprioceptive alterations that occur in Low Back Pain (LBP) patients. Movement variability is a crucial component of this analysis. During the past years a promising approach appears to be the application of non-linear indices. OBJECTIVE: The aim of the study was to compare movement variability, as expressed mainly by non-linear indices, at the pelvis and lumbar between LBP patients and healthy participants during gait. METHODS: Sixteen (16) LBP patients and thirteen (13) healthy control subjects (non-athletes) participated in the study. Participants walked on a treadmill at different walking conditions while recorded by a 6-infrared camera optoelectronic system. Kinematic variability of pelvic and lumbar movement was analyzed using linear (standard deviation) and non-linear indices (Maximal Lyapunov Exponent – LyE and Approximate Entropy – ApEn). RESULTS: Healthy subjects were found to have significantly greater mean values than LBP patients at seven pelvic and lumbar components in LyE, ApEn and SD. Specifically, the calculated LyE at the pelvis during normal gait was proven to have a sensitivity of 92.3% and a specificity of 90% in the discrimination of healthy subjects from LBP patients. Female subjects presented with higher variability in gait measures than males. CONCLUSION: Healthy participants presented with higher movement variability in their kinematic behavior in comparison to LBP patients. Lower variability values may be partly explained by the attempt of LBP patients to avoid painful end of range of motion positions. In this perspective non-linear indices seem to relate to qualitive characteristics of movement that need to be taken into consideration during rehabilitation.

The relation between falls risk and movement variability in Parkinson’s disease

2021 ◽  
Author(s):  
Steven Morrison ◽  
Jacquelyn Moxey ◽  
Nick Reilly ◽  
Daniel M. Russell ◽  
Karen M. Thomas ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Movement Variability ◽  
Falls Risk

scholarly journals Motor Chunking in Internally Guided Sequencing

2021 ◽  
Vol 11 (3) ◽  
pp. 292 ◽  
Author(s):  
Krishn Bera ◽  
Anuj Shukla ◽  
Raju S. Bapi
Keyword(s):  
Response Times ◽  
Skill Learning ◽  
Motor Tasks ◽  
Performance Improvements ◽  
Sequence Production ◽  
Serial Reaction ◽  
Motor Movements ◽  
Motor Actions ◽  
Reaction Task ◽  
Or Task

Motor skill learning involves the acquisition of sequential motor movements with practice. Studies have shown that we learn to execute these sequences efficiently by chaining several elementary actions in sub-sequences called motor chunks. Several experimental paradigms, such as serial reaction task, discrete sequence production, and m × n task, have investigated motor chunking in externally specified sequencing where the environment or task paradigm provides the sequence of stimuli, i.e., the responses are stimulus driven. In this study, we examine motor chunking in a class of more realistic motor tasks that involve internally guided sequencing where the sequence of motor actions is self-generated or internally specified. We employ a grid-navigation task as an exemplar of internally guided sequencing to investigate practice-driven performance improvements due to motor chunking. The participants performed the grid-sailing task (GST) (Fermin et al., 2010), which required navigating (by executing sequential keypresses) a 10 × 10 grid from start to goal position while using a particular type of key mapping between the three cursor movement directions and the three keyboard buttons. We provide empirical evidence for motor chunking in grid-navigation tasks by showing the emergence of subject-specific, unique temporal patterns in response times. Our findings show spontaneous chunking without pre-specified or externally guided structures while replicating the earlier results with a less constrained, internally guided sequencing paradigm.

scholarly journals Self-generation and sound intensity interactively modulate perceptual bias, but not perceptual sensitivity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadia Paraskevoudi ◽  
Iria SanMiguel
Keyword(s):  
Stimulus Intensity ◽  
Empirical Support ◽  
Sound Intensity ◽  
Perceptual Bias ◽  
Perceptual Processing ◽  
Interactive Effects ◽  
Just Noticeable Difference ◽  
External Sources ◽  
Motor Actions ◽  
Near Threshold

AbstractThe ability to distinguish self-generated stimuli from those caused by external sources is critical for all behaving organisms. Although many studies point to a sensory attenuation of self-generated stimuli, recent evidence suggests that motor actions can result in either attenuated or enhanced perceptual processing depending on the environmental context (i.e., stimulus intensity). The present study employed 2-AFC sound detection and loudness discrimination tasks to test whether sound source (self- or externally-generated) and stimulus intensity (supra- or near-threshold) interactively modulate detection ability and loudness perception. Self-generation did not affect detection and discrimination sensitivity (i.e., detection thresholds and Just Noticeable Difference, respectively). However, in the discrimination task, we observed a significant interaction between self-generation and intensity on perceptual bias (i.e. Point of Subjective Equality). Supra-threshold self-generated sounds were perceived softer than externally-generated ones, while at near-threshold intensities self-generated sounds were perceived louder than externally-generated ones. Our findings provide empirical support to recent theories on how predictions and signal intensity modulate perceptual processing, pointing to interactive effects of intensity and self-generation that seem to be driven by a biased estimate of perceived loudness, rather by changes in detection and discrimination sensitivity.

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