Motor Programs Research Articles

An hourglass circuit motif transforms a motor program via subcellularly localized muscle calcium signaling and contraction.

Neural control of muscle function is fundamental to animal behavior. Many muscles can generate multiple distinct behaviors. Nonetheless, individual muscle cells are generally regarded as the smallest units of motor control. We report that muscle cells can alter behavior by contracting subcellularly. We previously discovered that noxious tastes reverse the net flow of particles through the C. elegans pharynx, a neuromuscular pump, resulting in spitting. We now show that spitting results from the subcellular contraction of the anterior region of the pm3 muscle cell. Subcellularly localized calcium increases accompany this contraction. Spitting is controlled by an 'hourglass' circuit motif: parallel neural pathways converge onto a single motor neuron that differentially controls multiple muscles and the critical subcellular muscle compartment. We conclude that subcellular muscle units enable modulatory motor control and propose that subcellular muscle contraction is a fundamental mechanism by which neurons can reshape behavior.

Brain changes underlying progression of speech motor programming impairment.

Aquired apraxia of speech is a disorder that impairs speech production, despite intact peripheral neuromotor function. Its pathomechanism remains to be established. Neurodegenerative lesion models provide an unequalled opportunity to explore the neural correlates of apraxia of speech, which is present in a subset of patients diagnosed with non-semantic variants of primary progressive aphasia. The normalized pairwise variability index, an acoustic measure of speech motor programming, has shown high sensitivity and specificity for apraxia of speech in cross-sectional studies. Here, we aimed to examine the strength of the pairwise variability index and overall word duration (i.e. articulation rate) as markers of progressive motor programming deficits in primary progressive aphasia with apraxia of speech. Seventy-nine individuals diagnosed with primary progressive aphasia (39 with non-fluent variant and 40 with logopenic variant) and 40 matched healthy controls participated. Patients were followed-up annually (range 1–6 years, median number of visits = 2). All participants completed a speech assessment task and a high-resolution MRI. Our analyses investigated trajectories of speech production (e.g. pairwise variablity index and word duration) and associations with cortical atrophy in the patients. At first presentation, word duration differentiated the nonfluent and logopenic cases statistically, but the range of scores overlapped substantially across groups. Longitudinally, we observed progressive deterioration in pairwise variability index and word duration specific to the non-fluent group only. The pairwise variability index showed particularly strong associations with progressive atrophy in speech motor programming brain regions. Of novelty, our results uncovered a key role of the right frontal gyrus in underpinning speech motor programming changes in non-fluent cases, highlighting the importance of right-brain regions in responding to progressive neurological changes in the speech motor network. Taken together, our findings validate the use of a new metric, the pairwise variability index, as a robust marker of apraxia of speech in contrast to more generic measures of speaking rate. Sensitive/specific neuroimaging biomarkers of the emergence and progression of speech impairments will be useful to inform theories of the pathomechanisms underpinning impaired speech motor control. Our findings justify developing more sensitive measures of rhythmic temporal control of speech that may enable confident detection of emerging speech disturbances and more sensitive tracking of intervention-related changes for pharmacological, neuromodulatory and behavioural interventions. A more reliable detection of speech disturbances has relevance for patient care, with predominance of progressive apraxia of speech a high-risk factor for later diagnosis of progressive supranuclear palsy or corticobasal degeneration.

The effect of programming immediate and delayed feedback according to the stages of building the motor program on learning some compound offensive skills in basketball for students

The effect of programming immediate and delayed feedback according to the stages of building the motor program on learning some compound offensive skills in basketball for students

Study on improving coordination skills in women’s basketball game

The purpose of this research is to highlight the effectiveness of the proposed motor programme for the improvement of coordination skills in female basketball players aged 13-15 years. The implementation of a motor programme focused on the development of coordination skills leads to their improvement and could have a significant impact on future results/performance. The participants in this study were 68 female basketball players who were divided into two groups, an experimental group (n = 36) and a control group (n = 32). The following tests were applied to assess the development level of their coordination skills: Tapping test, Rope jumping test, Alternate hand wall toss test, Square test and Kinaesthetic test. Both groups were assessed at the beginning of the competition season and at the end of the 6 months of specific motor programme. The programme proposed and applied to the experimental group consisted of: slalom circuits, elastic rope jumping, static and dynamic balance exercises, eye-hand, hand-foot and eye-foot coordination exercises, throwing and catching objects and rhythm-building exercises. The following research methods were used: literature review, experiment method, test method, mathematical and statistical method, graphical method. The results of the study showed that the experimental group recorded improved values in the final test compared to the results obtained by the control group. In conclusion, the proposed motor programme has proven its effectiveness as regards the improvement of coordination skills in female basketball players aged 13-15 years.

Replay of innate vocal patterns during night sleep in suboscines.

Activation of forebrain circuitry during sleep has been variably characterized as 'pre- or replay' and has been linked to memory consolidation. The evolutionary origins of this mechanism, however, are unknown. Sleep activation of the sensorimotor pathways of learned birdsong is a particularly useful model system because the muscles controlling the vocal organ are activated, revealing syringeal activity patterns for direct comparison with those of daytime vocal activity. Here, we show that suboscine birds, which develop their species-typical songs innately without the elaborate forebrain-thalamic circuitry of the vocal learning taxa, also engage in replay during sleep. In two tyrannid species, the characteristic syringeal activation patterns of the song could also be identified during sleep. Similar to song-learning oscines, the burst structure was more variable during sleep than daytime song production. In kiskadees (Pitangus sulphuratus), a second vocalization, which is part of a multi-modal display, was also replayed during sleep along with one component of the visual display. These data show unambiguously that variable 'replay' of stereotyped vocal motor programmes is not restricted to programmes confined within forebrain circuitry. The proposed effects on vocal motor programme maintenance are, therefore, building on a pre-existing neural mechanism that predates the evolution of learned vocal motor behaviour.

AOP Report: Inhibition of Chitin Synthase 1 Leading to Increased Mortality in Arthropods.

AOP Report: Inhibition of Chitin Synthase 1 Leading to Increased Mortality in Arthropods.

Organelle calcium-derived voltage oscillations in pacemaker neurons drive the motor program for food-seeking behavior in Aplysia.

The expression of motivated behaviors depends on both external and internally arising neural stimuli, yet the intrinsic releasing mechanisms for such variably occurring behaviors remain elusive. In isolated nervous system preparations of Aplysia, we have found that irregularly expressed cycles of motor output underlying food-seeking behavior arise from regular membrane potential oscillations of varying magnitude in an identified pair of interneurons (B63) in the bilateral buccal ganglia. This rhythmic signal, which is specific to the B63 cells, is generated by organelle-derived intracellular calcium fluxes that activate voltage-independent plasma membrane channels. The resulting voltage oscillation spreads throughout a subset of gap junction-coupled buccal network neurons and by triggering plateau potential-mediated bursts in B63, can initiate motor output driving food-seeking action. Thus, an atypical neuronal pacemaker mechanism, based on rhythmic intracellular calcium store release and intercellular propagation, can act as an autonomous intrinsic releaser for the occurrence of a motivated behavior.

Semantic verbal fluency brain network: delineating a physiological basis for the functional hubs using dual-echo ASL and graph theory approach

Objective. Semantic verbal fluency (SFV) is a cognitive process that engages and modulates specific brain areas related to language comprehension and production, decision making, response inhibition, and memory retrieval. The impairment of the brain network responsible for these functions is related to various neurological conditions, and different strategies have been proposed to assess SVF-related deficits in such diseases. In the present study, the concomitant changes of brain perfusion and functional connectivity were investigated during the resting state and SVF task performance. Approach. Arterial spin labeling (ASL), a perfusion-based magnetic resonance imaging (MRI) method, was used with a pseudocontinuous labeling approach and dual-echo readout in 28 healthy right-handed Brazilian Portuguese speakers. The acquisition was performed in a resting state condition and during the performance of a SVF task. Main results. During task performance, a significant increase in cerebral blood flow (CBF) was observed in language-related regions of the frontal lobe, including Brodmann’s areas 6, 9, 45, and 47, associated with semantic processing, word retrieval, and speech motor programming. Such regions, along with the posterior cingulate, showed a crucial role in the SVF functional network, assessed by seed-to-voxel and graph analysis. Our approach successfully overcame the generalization problem regarding functional MRI (fMRI) graph analysis with cognitive, task-based paradigms. Moreover, the CBF maps enabled the functional assessment of orbital frontal and temporal regions commonly affected by magnetic susceptibility artifacts in conventional T2*-weighted fMRI approaches. Significance. Our results demonstrated the capability of ASL to evaluate perfusion alterations and functional patterns simultaneously regarding the SVF network providing a quantitative physiological basis to functional hubs in this network, which may support future clinical studies.

Perception-action integration in young age—A cross-sectional EEG study

Humans differ in their capacity for integrating perceived events and related actions. The “Theory of event coding” (TEC) conceptualizes how stimuli and actions are cognitively bound into a common functional representation (or “code”), known as the “event file”. To date, however, the neural processes underlying the development of event file coding mechanisms across age are largely unclear. We investigated age-related neural changes of event file coding from late childhood to early adulthood, using EEG signal decompositions methods. We included a group of healthy participants (n = 91) between 10 and 30 years, performing an event file paradigm. Results of this study revealed age-related effects on event file coding processes both at the behavioural and the neurophysiological level. Performance accuracy data showed that event file unbinding und rebinding processes become more efficient from late childhood to early adulthood. These behavioural effects are reflected by age-related effects in two neurophysiological subprocesses associated with the superior parietal cortex (BA7) as revealed in the analyses using EEG signal decomposition. The first process entails mapping and association processes between stimulus and response; whereas, the second comprises inhibitory control subprocesses subserving the selection of the relevant motor programme amongst competing response options.

The Complement of Projection Neurons Activated Determines the Type of Feeding Motor Program in Aplysia.

Multiple projection neurons are often activated to initiate behavior. A question that then arises is, what is the unique functional role of each neuron activated? We address this issue in the feeding system of Aplysia. Previous experiments identified a projection neuron [cerebral buccal interneuron 2 (CBI-2)] that can trigger ingestive motor programs but only after it is repeatedly stimulated, i.e., initial programs are poorly defined. As CBI-2 stimulation continues, programs become progressively more ingestive (repetition priming occurs). This priming results, at least in part, from persistent actions of peptide cotransmitters released from CBI-2. We now show that in some preparations repetition priming does not occur. There is no clear seasonal effect; priming and non-priming preparations are encountered throughout the year. CBI-2 is electrically coupled to a second projection neuron, cerebral buccal interneuron 3 (CBI-3). In preparations in which priming does not occur, we show that ingestive activity is generated when CBI-2 and CBI-3 are coactivated. Programs are immediately ingestive, i.e., priming is not necessary, and a persistent state is not induced. Our data suggest that dynamic changes in the configuration of activity can vary and be determined by the complement of projection neurons that trigger activity.

Severe speech impairment is a distinguishing feature of FOXP1-related disorder.

To delineate the speech and language phenotype of a cohort of individuals with FOXP1-related disorder. We administered a standardized test battery to examine speech and oral motor function, receptive and expressive language, non-verbal cognition, and adaptive behaviour. Clinical history and cognitive assessments were analysed together with speech and language findings. Twenty-nine patients (17 females, 12 males; mean age 9y 6mo; median age 8y [range 2y 7mo-33y]; SD 6y 5mo) with pathogenic FOXP1 variants (14 truncating, three missense, three splice site, one in-frame deletion, eight cytogenic deletions; 28 out of 29 were de novo variants) were studied. All had atypical speech, with 21 being verbal and eight minimally verbal. All verbal patients had dysarthric and apraxic features, with phonological deficits in most (14 out of 16). Language scores were low overall. In the 21 individuals who carried truncating or splice site variants and small deletions, expressive abilities were relatively preserved compared with comprehension. FOXP1-related disorder is characterized by a complex speech and language phenotype with prominent dysarthria, broader motor planning and programming deficits, and linguistic-based phonological errors. Diagnosis of the speech phenotype associated with FOXP1-related dysfunction will inform early targeted therapy. What this paper adds Individuals with FOXP1-related disorder have a complex speech and language phenotype. Dysarthria, which impairs intelligibility, is the dominant feature of the speech profile. No participants were receiving speech therapy for dysarthria, but were good candidates for therapy Features of speech apraxia occur alongside persistent phonological errors. Language abilities are low overall; however, expressive language is a relative strength.

Representing strangers in personal space triggers coding of defensive hand movement

Our brain codes manipulable tools as possibilities for action, particularly for those surrounding the body. Recent studies showed people would adjust their motor program when observing others around their own bodies (i.e. in the personal space). However, it remained unclear whether representing a personal space invader can automatically trigger motor coding.To address this, we devised an interaction task to measure the activation of pushing movements in facing a stranger approaching into personal space. The LRP (lateralized readiness potential) analyses revealed that observing a stranger in personal space caused an initial LRP bias associated with pushing movements, and an LRP deflection before responding of pull, suggesting representing personal space invaders activated the motor coding of push. The behavioral results showed the personal space intrusion prolonged the reaction time of participants’ subsequent instructed pulling responses. The results of experiment 2 confirmed the behavioral observation of experiment 1 and further revealed the relationship between the response bias of push and social anxiety. Together, the present study demonstrates representing a stranger in personal space activated coding of defensive hand movements and biased subsequent motor responses.

What information is being acquired during the period of Quiet Eye? Comment on Vickers

Sports and athletes’ highest performance offer a fascinating scenario to investigate perceptual-motor expertise. The remarkable work of Joan Vickers has captured this opportunity and built a valuable experimental paradigm. Our commentary emphasizes what information is being acquired during the period of Quiet Eye (QE), capable to produce successful performance. First, an extended notion of visual system that includes posture is presented. It is suggested that QE would represent a collective postural effort (resulting from movements of eyes, head, trunk, and whole body) to acquire the relevant information available in the optic flow. Second, the contribution of neural structures and functioning for vision and attention is discussed. Models of neural networks of attention and two visual systems are described with respect to QE and some questions about action parameters and motor programs are raised.

Automated paste preparation machine

Ayurveda industry is one of the golden industries in ancient India which over the period had declined is witnessing a new surge up; this paper describes an automated approach for developing automated paste preparation machines for the health sector and Ayurveda industry. Automated paste preparation machine models are prepared on the basis of requirements and then tested and finally go into the manufacturing stage. This paper basically describes the methodology of preparation of machine models. In these automated paste preparation machine models, we use cam follower mechanism for the timed opening of valves to ensure the correct amount of ingredients to be instilled into the bowl. Control of opening and closing of valves through cam follower mechanism is achieved by the programming of gear motor with the help of Arduino Uno. An experimental case study is presented to show advantages, which include a verified reduction in model development time and improved modeling consistency and quality.

Handwriting in Alzheimer's Disease.

Agraphia is a typical feature in the clinical course of Alzheimer's disease (AD). Assess the differences between AD and normal aging as regards kinematographic features of handwriting and elucidate writing deficits in AD. The study included 23 patients with AD (78.09 years/SD = 7.12; MMSE 21.39/SD = 3.61) and 34 healthy controls (75.56 years/SD = 5.85; MMSE 29.06/SD = 0.78). Both groups performed alphabetical and non-alphabetical writing tasks. The kinematographic assessment included the average number of inversions per stroke (NIV; number of peaks in the velocity profile in a single up or down stroke), percentage of automated segments, frequency (average number of strokes per second), writing pressure, and writing velocity on paper. A total of 14 patients showed overt writing difficulties reflected by omissions or substitutions of letters. AD patients showed less automated movements (as measured by NIV), lower writing velocity, and lower frequency of up-and-down strokes in non-alphabetical as well as in alphabetical writing. In the patient group, Spearman correlation analysis between overt writing performance and NIV was significant. That means patients who had less errors in writing a sentence showed a higher automaticity in handwriting. The correctness of alphabetical writing and some kinematographic measures in writing non-alphabetical material reached excellent diagnostic values in ROC analyses. There was no difference in the application of pressure on the pen between patients and controls. Writing disorders are multi-componential in AD and not strictly limited to one processing level. The slow and poorly automated execution of motor programs is not bound to alphabetical material.

Evaluation of a 12-Week Classroom-Based Gross Motor Program Designed to Enhance Motor Proficiency, Mathematics and Reading Outcomes of Year 1 School Children: A Pilot Study

This study explored whether Year 1 school children exposed to a 12-week classroom-based gross motor program progressed differently than Year 1 children undertaking their regular school program in motor proficiency, mathematics, and reading outcomes. Fifty-five Australian Year 1 school children (25 boys, 30 girls, mean age 6.77 ± 0.40 years) were exposed to either (i) their normal school program (Class N) or (ii) a 12-week program comprised of gross motor circuits and physically active: a) reading lessons (Class R) or b) mathematics lessons (Class M). Motor proficiency and academic performance in mathematics and reading were assessed using the Bruininks–Oseretsky Test of Motor Proficiency (2nd Edition) and the Wechsler Individual Achievement Test—2nd Edition—Australian Standardised Edition, respectively. Differences in outcomes between classes following the 12-week program were assessed. Mean change scores for the mathematics composite were significantly greater for participants in Class R (9.61 ± 5.62, p = .001) and Class M (7.57 ± 5.79, p = .019) than for participants in Class N (0.76 ± 8.00). Mean change scores for reading (11.54 ± 7.51, p = .017) and total motor composites (6.12 ± 5.07, p = .034) were also significantly greater for participants in Class M than Class N (4.47 ± 3.50 and 0.82 ± 4.38 respectively). A 12-week classroom-based gross motor program may be beneficial for motor skill development and learning in Year 1 school children. This pilot evaluation may usefully inform future experimental studies to further investigate whether classroom-based motor skill programs have a beneficial effect on motor proficiency and academic outcomes in children in the early years of primary school.

Auditory decisions in the supplementary motor area.

In human speech and communication across various species, recognizing and categorizing sounds is fundamental for the selection of appropriate behaviors. However, how does the brain decide which action to perform based on sounds? We explored whether the supplementary motor area (SMA), responsible for linking sensory information to motor programs, also accounts for auditory-driven decision making. To this end, we trained two rhesus monkeys to discriminate between numerous naturalistic sounds and words learned as target (T) or non-target (nT) categories. We found that the SMA at single and population neuronal levels perform decision-related computations that transition from auditory to movement representations in this task. Moreover, we demonstrated that the neural population is organized orthogonally during the auditory and the movement periods, implying that the SMA performs different computations. In conclusion, our results suggest that the SMA integrates acoustic information in order to form categorical signals that drive behavior.

Examination and Comparison of Theta Band Connectivity in Left- and Right-Hand Dominant Individuals throughout a Motor Skill Acquisition

The majority of the population identifies as right-hand dominant, with a minority 10.6% identifying as left-hand dominant. Social factors may partially skew the distribution, but it remains that left-hand dominant individuals make up approximately 40 million people in the United States alone and yet, remain underrepresented in the motor control literature. Recent research has revealed behavioral and neurological differences between populations, therein overturning assumptions of a simple hemispheric flip in motor-related activations. The present work showed differentially adaptable motor programs between populations and found fundamental differences in methods of skill acquisition highlighting underlying neural strategies unique to each population. Difference maps and descriptive metrics of coherent activation patterns showed differences in how theta oscillations were utilized. The right-hand group relied on occipital parietal lobe connectivity for visual information integration necessary to inform the motor task, while the left-hand group relied on a more frontal lobe localized cognitive based approach. The findings provide insight into potential alternative methods of information integration and emphasize the importance for inclusion of the left-hand dominant population in the growing conceptualization of the brain promoting the generation of a more complete, stable, and accurate understanding of our complex biology.

FMS Effects of a Motor Program for Children With Autism Spectrum Disorders.

The current study evaluated the effectiveness of a motor program that specifically targeted fundamental motor skills (FMS) in children with ASD. The experimental group (n=21) participated in a 9-week program with motor instructions for 80 minutes/day, three days/week, while the control group (n=29) did not participate in the program. We measured FMS (using the Test of Gross Motor Development-3) one-week before, one-week after, and two-months after the program. Children in the experimental group had significantly larger FMS improvements than the controls on both locomotor and ball skills immediately following the program, and these participants showed continuous improvement on locomotor, but not ball skills, at 2-months follow-up. In individual analyses, 80% of children in the experimental group versus 29% of children in the control group showed continuous locomotor skills improvement beyond their pre-test levels. These findings highlight the importance of both a long-term motor development intervention and an individualized approach for evaluating improved FMS among children with ASD.

Right up- left down

BackgroundWhen performing the clock-drawing test healthy participants often draw the clock face using a counter clockwise movement. The reason for this circular directional bias is not known. These actions may be related to the development of motor or attentional programs that associate leftward with downward movements, and rightward with upward movements. MethodsTo further examine this down-left, up-right programming hypothesis, we examined the direction of circular movements made during cursive writing by dividing the first curved movements into the following pairs, up versus down, and leftward versus rightward. Results and conclusionsWith almost all the letters analyzed, when initially moving upward there was a simultaneous rightward movement and when initially moving downward a leftward movement. The results suggest that there appears to be a relationship between downward and leftward movements as well as between upward and right rightward movements. In addition, there is some evidence to suggest that the right-upward movements may be mediated by the left hemisphere and left-downward movements by the right hemisphere. Although our results suggest motor or spatial attentional programs may account for counter clockwise face drawing, activities such as learned writing direction may influence this spatial bias. Therefore, additional research is needed to better understand if these spatial biases are learned or intrinsic and the neuropsychological mechanisms that might account for these asymmetries.