Efectividad de la intervención motora temprana en el desarrollo motor de los niños con parálisis cerebral entre 3 y 5 años de edad. Revisión sistemática / Effectiveness of early motor interventions in children with cerebral palsy between 3 to 5 years of age: Systematic review

La intervención motora temprana es esencial en niños con parálisis cerebral; sin embargo, se desconoce su efectividad entre los 3 y los 5años. El objetivo fue determinar la efectividad de la intervención motora temprana en el desarrollo motor de dicha población. Se realizó una revisión sistemática de literatura acerca de intervenciones motoras tempranas realizada en diferentes bases de datos como Pubmed/Medline, PEDro, OTSeeker, Embase y LILACS. Finalmente se seleccionaron 18 artículos, de los cuales 4 presentaron cambios a favor del grupo experimental en los desenlaces desarrollo motor global y función motora manual, con la terapia de integración sensorial y la terapia de movimiento inducido por restricción, respectivamente; no obstante, los resultados no fueron estadísticamente significativos y el nivel de evidencia fue bajo. La intervención motora temprana podría incluirse con precaución para la mejoría del desarrollo motor global y la función manual. Es necesario realizar estudios de mayor calidad metodológica. (AU)

Early motor intervention is essential in children with cerebral palsy; however, it is unknown its effectiveness between 3 to 5years. The objective was to determinate the effectiveness of early motor intervention in the motor development of this population. A systematic literature search was performed in Pubmed/Medline, PEDro, OTSeeker, Embase, and LILACS. Finally, 18 articles were selected, of which 4 showed favorable changes in the experimental group in the outcomes of overall motor development and manual motor function, with sensory integration therapy and movement-induced restriction therapy, respectively; however, the results were not statistically significant, and the level of evidence was low. Early motor intervention could be cautiously considered for improving overall motor development and manual function. Higher-quality methodological studies are necessary. (AU)

Ηand dexterities assessment in stroke patients based on augmented reality and machine learning through a box and block test.

A popular and widely suggested measure for assessing unilateral hand motor skills in stroke patients is the box and block test (BBT). Our study aimed to create an augmented reality enhanced version of the BBT (AR-BBT) and evaluate its correlation to the original BBT for stroke patients. Following G-power analysis, clinical examination, and inclusion-exclusion criteria, 31 stroke patients were included in this study. AR-BBT was developed using the Open Source Computer Vision Library (OpenCV). The MediaPipe's hand tracking library uses a palm and a hand landmark machine learning model to detect and track hands. A computer and a depth camera were employed in the clinical evaluation of AR-BBT following the principles of traditional BBT. A strong correlation was achieved between the number of blocks moved in the BBT and the AR-BBT on the hemiplegic side (Pearson correlation = 0.918) and a positive statistically significant correlation (p = 0.000008). The conventional BBT is currently the preferred assessment method. However, our approach offers an advantage, as it suggests that an AR-BBT solution could remotely monitor the assessment of a home-based rehabilitation program and provide additional hand kinematic information for hand dexterities in AR environment conditions. Furthermore, it employs minimal hardware equipment.

Study protocol to examine the effects of acute exercise on motor learning and brain activity in children with developmental coordination disorder (ExLe-Brain-DCD).

INTRODUCTION: Developmental coordination disorder (DCD) is one of the most prevalent pediatric chronic conditions. Without proper intervention, significant delays in motor skill performance and learning may persist until adulthood. Moderate-to-vigorous physical exercise has been proven to improve motor learning (adaptation and consolidation) in children with or without disorders. However, the effect of a short bout of physical exercise on motor adaptation and consolidation in children with DCD has not been examined. Furthermore, the role of perceptual-motor integration and attention as mediators of learning has not been examined via neuroimaging in this population. OBJECTIVES: Therefore, the primary aims of this project will be to compare children with and without DCD to (a) examine the effect of acute exercise on motor learning (adaptation and consolidation) while performing a rotational visuo-motor adaptation task (rVMA), and (b) explore cortical activation in the dorsolateral- and ventrolateral-prefrontal cortex areas while learning the rVMA task under rest or post-exercise conditions. METHODS: One hundred twenty children will be recruited (60 DCD, 60 controls) and within-cohort randomly assigned to either exercise (13-minute shuttle run task) or rest prior to performing the rVMA task. Adaptation and consolidation will be evaluated via two error variables and three retention tests (1h, 24h and 7 days post adaptation). Cortical activation will be registered via functional near-infrared spectroscopy (fNIRS) during the baseline, adaptation, and consolidation. DISCUSSION: We expect to find exercise benefits on motor learning and attention so that children with DCD profiles will be closer to those of children with typical development. The results of this project will provide further evidence to: (a) better characterize children with DCD for the design of educational materials, and (b) establish acute exercise as a potential intervention to improve motor learning and attention.

The role of fundamental movement skills on children's physical activity during different segments of the school day.

BACKGROUND: Although prior studies have demonstrated that children with high levels of fundamental movement skill (FMS) are more active throughout the day, little is known about children's FMS and their physical activity (PA) during different segments of the school day (e.g., recess, lunch break, and physical education). The present study focused on FMS and moderate-to-vigorous PA (MVPA) during school day and identifies the association between children's FMS and MVPA during different segments of the school day in China. METHODS: A total of 322 children (boys n = 163, girls n = 159; Mage = 8.12, SD = 1.22 years) from four elementary schools involved in this study. Children's FMS and MVPA were measured using the Test of Gross Motor Development-2nd edition (TGMD-2) and hip-mounted accelerometers. Data such as height, weight, and socio-economic status (SES) were also obtained. Multilevel mixed regression models were used to examine the cross-sectional associations between FMS and MVPA. Models were adjusted for gender, age, standardized body mass index, and SES. RESULTS: Children engaged in 32.19 min of MVPA during the whole school day. Boys were more active than girls and had higher object-control skills competency. Locomotor skills were positively associated with children's long recess (B = 1.063) and short recess time (B = 1.502) MVPA. Object-control skills were positively correlated with children's MVPA time during long recess (B = 1.244) and physical education (PE) lessons (B = 1.171). CONCLUSION: The findings highlight the importance of developing both locomotor and object-control skills in elementary schools to lead more MVPA engagement during different segments of the school day.

Long-term outcomes of visual motor integration and motor development children with retinopathy of prematurity.

Premature infants have a risk of neurodevelopmental deficits. Little is known, however, about how retinopathy of prematurity (ROP) affects visual motor integration (VMI), which is necessary for both fine motor skills and further school abilities. Due to the systemic escape of bevacizumab in the treatment of ROP, concerns regarding the long-term neurodevelopmental effect of the drug have arisen. The aim is to evaluate VMI and motor development long-term outcomes after intravitreal bevacizumab (IVB) injection and laser treatment for ROP. Two groups of premature children were included: Bevacizumab group - 16 premature children who received IVB treatment and laser group - 23 premature children who underwent laser photocoagulation treatment in this single center cross-sectional study. At 2-6 years of age, VMI (Beery-Buktenica Developmental Test), motor development (Peabody Developmental Motor Scales-2), visual acuity, and refractive status were assessed. The incidence of abnormal visual function was significantly higher in bevacizumab group than in laser group (p = 0.022). The incidence of abnormal VMI skill was significantly higher in bevacizumab group than in laser group (p = 0.024). Incidences of abnormal gross, fine, and total motor skills were significantly higher in bevacizumab group compared to laser group (p < 0.05). Premature children who received bevacizumab for ROP demonstrated significantly lower VMI and motor development features than those with laser treatment at preschool age. Although our results suggest the relevance of bevacizumab injection in impaired VMI and motor development outcomes, general level of sickness rather than treatment might be the cause of delayed motor development.

Cholecystokinin facilitates motor skill learning by modulating neuroplasticity in the motor cortex.

Cholecystokinin (CCK) is an essential modulator for neuroplasticity in sensory and emotional domains. Here, we investigated the role of CCK in motor learning using a single pellet reaching task in mice. Mice with a knockout of Cck gene (Cck-/-) or blockade of CCK-B receptor (CCKBR) showed defective motor learning ability; the success rate of retrieving reward remained at the baseline level compared to the wildtype mice with significantly increased success rate. We observed no long-term potentiation upon high-frequency stimulation in the motor cortex of Cck-/- mice, indicating a possible association between motor learning deficiency and neuroplasticity in the motor cortex. In vivo calcium imaging demonstrated that the deficiency of CCK signaling disrupted the refinement of population neuronal activity in the motor cortex during motor skill training. Anatomical tracing revealed direct projections from CCK-expressing neurons in the rhinal cortex to the motor cortex. Inactivation of the CCK neurons in the rhinal cortex that project to the motor cortex bilaterally using chemogenetic methods significantly suppressed motor learning, and intraperitoneal application of CCK4, a tetrapeptide CCK agonist, rescued the motor learning deficits of Cck-/- mice. In summary, our results suggest that CCK, which could be provided from the rhinal cortex, may surpport motor skill learning by modulating neuroplasticity in the motor cortex.

Pre-Pregnancy Obesity and Infants' Motor Development within the First Twelve Months of Life: Who Is Expected to Be the Ultimate Carrier of the Obesity Burden?

INTRODUCTION: Pre-pregnancy obesity is a significant public health concern with profound implications for maternal and child health. The burgeoning evidence suggests that maternal obesity prior to conception is intricately linked with an increased risk of gestational complications, as well as with adverse neonatal outcomes. Furthermore, the long and short-term health of offspring, including the risk of early motor development impairment, obesity, and metabolic syndrome in childhood and adulthood, may be adversely affected as well. Addressing pre-pregnancy obesity is critical for improving overall maternal and child health outcomes, and therefore, the aim of this study was to evaluate the connections linking pre-pregnancy obesity with infants' motor development within the first twelve months of infants' lives. MATERIAL AND METHODS: This study included 200 mother-infant pairs divided into two groups based on their pre-pregnancy body mass index values. To assess infants' early motor development, we used the Alberta Infant Motor Scale (AIMS) and evaluated the parameters of infants' early motor development at the ages of three, six, nine, and twelve months. RESULTS: Pre-pregnancy overweight/obesity was significantly associated with excessive gestational weight gain (p < 0.001), fetal macrosomia (p = 0.022), and a family history of diabetes and cardiovascular diseases (p = 0.048 and p = 0.041, respectively), as well as with all observed parameters of early motor development at the ages of three, six, nine, and twelve months: AIMS 3 months total (p < 0.001), AIMS 6 months total (p < 0.001), AIMS 9 months total (p < 0.001), and AIMS 12 months total (p < 0.001). Furthermore, pre-pregnancy overweight/obesity was a significant predictor for AIMS 6 months total (p = 0.043) and AIMS 6 months supination (p = 0.017). CONCLUSIONS: Pre-pregnancy obesity is a critical determinant of pregnancy outcomes and offspring early motor development, with possible far-reaching implications for children's long-term well-being. Addressing this issue requires a comprehensive approach that includes preconception weight management, targeted interventions during the pregnancy and postpartum periods, and ongoing research to better understand the underlying mechanisms and develop effective strategies for prevention and management.

Effectiveness of Power Exercises Compared to Traditional Strength Exercises on Motor Skills, Muscle Performance and Functional Muscle Strength of Children with Attention Deficit Hyperactivity Disorder: A Single-Blind Randomized Controlled Trial.

The aim of this study was to compare the impact of 8-weeks of power exercises compared to traditional strength exercises on motor abilities, muscle performance, and functional strength in children with ADHD. A total of 34 children with ADHD were randomized into two groups to receive functional power training (n = 17, M age: 121.2 ± 16.6 months) and traditional strength training (n = 17, M age: 116.1 ± 13.4 months). After the 8-week intervention, two-way ANOVA results with 95% confidence intervals showed no differences between the groups in motor skills, muscle power, or functional muscle strength. However, the functional power training group had larger effect sizes and greater increases in total motor composite score (10% vs 7%), body coordination (13.8% vs 4.9%) and bilateral coordination (38.8% vs 27.9%) than the traditional strength training group. The power training group also exhibited catch-up growth with typically developing peers. These findings suggest that power exercises may be more effective than strength exercises for rapid force generation in daily life, particularly for children with ADHD.

Information flow between motor cortex and striatum reverses during skill learning.

The coordination of neural activity across brain areas during a specific behavior is often interpreted as neural communication involved in controlling the behavior. However, whether information relevant to the behavior is actually transferred between areas is often untested. Here, we used information-theoretic tools to quantify how motor cortex and striatum encode and exchange behaviorally relevant information about specific reach-to-grasp movement features during skill learning in rats. We found a temporal shift in the encoding of behaviorally relevant information during skill learning, as well as a reversal in the primary direction of behaviorally relevant information flow, from cortex-to-striatum during naive movements to striatum-to-cortex during skilled movements. Standard analytical methods that quantify the evolution of overall neural activity during learning-such as changes in neural signal amplitude or the overall exchange of information between areas-failed to capture these behaviorally relevant information dynamics. Using these standard methods, we instead found a consistent coactivation of overall neural signals during movement production and a bidirectional increase in overall information propagation between areas during learning. Our results show that skill learning is achieved through a transformation in how behaviorally relevant information is routed across cortical and subcortical brain areas and that isolating the components of neural activity relevant to and informative about behavior is critical to uncover directional interactions within a coactive and coordinated network.

Distinct learning, retention, and generalization patterns in de novo learning versus motor adaptation.

People correct for movement errors when acquiring new motor skills (de novo learning) or adapting well-known movements (motor adaptation). While de novo learning establishes new control policies, adaptation modifies existing ones, and previous work have distinguished behavioral and underlying brain mechanisms for each motor learning type. However, it is still unclear whether learning in each type interferes with the other. In study 1, we use a within-subjects design where participants train with both 30° visuomotor rotation and mirror reversal perturbations, to compare adaptation and de novo learning respectively. We find no perturbation order effects, and find no evidence for differences in learning rates and asymptotes for both perturbations. Explicit instructions also provide an advantage during early learning in both perturbations. However, mirror reversal learning shows larger inter-participant variability and slower movement initiation. Furthermore, we only observe reach aftereffects following rotation training. In study 2, we incorporate the mirror reversal in a browser-based task, to investigate under-studied de novo learning mechanisms like retention and generalization. Learning persists across three or more days, substantially transfers to the untrained hand, and to targets on both sides of the mirror axis. Our results extend insights for distinguishing motor skill acquisition from adapting well-known movements.

Selective plasticity of layer 2/3 inputs onto distal forelimb controlling layer 5 corticospinal neurons with skilled grasp motor training.

Layer 5 neurons of the neocortex receive their principal inputs from layer 2/3 neurons. We seek to identify the nature and extent of the plasticity of these projections with motor learning. Using optogenetic and viral intersectional tools to selectively stimulate distinct neuronal subsets in rat primary motor cortex, we simultaneously record from pairs of corticospinal neurons associated with distinct features of motor output control: distal forelimb vs. proximal forelimb. Activation of Channelrhodopsin2-expressing layer 2/3 afferents onto layer 5 in untrained animals produces greater monosynaptic excitation of neurons controlling the proximal forelimb. Following skilled grasp training, layer 2/3 inputs onto corticospinal neurons controlling the distal forelimb associated with skilled grasping become significantly stronger. Moreover, peak excitatory response amplitude nearly doubles while latency shortens, and excitatory-to-inhibitory latencies become significantly prolonged. These findings demonstrate distinct, highly segregated, and cell-specific plasticity of layer 2/3 projections during skilled grasp motor learning.

Activities of daily living, self-efficacy and motor skill related fitness and the interrelation in children with moderate and severe Developmental Coordination Disorder.

BACKGROUND: Children with Developmental Coordination Disorder (DCD) are diagnosed based on poor motor skills that impact their daily activities. However, this may also lead to lower predilection and participation in physical activities and a higher risk to develop health problems. OBJECTIVE: To determine motor skill related levels in children with moderate and severe DCD and compare that to typically developing children (TD). The study also aimed to determine the level of activities of daily living (ADL) as reported by their parent and self-efficacy as reported by the children. Lastly, the relation of motor skill related fitness, ADL, and self-efficacy has been examined. METHODS: A cross-sectional study has compared TD children (n = 105) and children with DCD (n = 109; 45 moderate DCD and 64 severe DCD) from elementary schools in Tunisia between 7 and 10 years of age. The DCDDaily-Questionnaire and Children's Self-perceptions of Adequacy in and Predilection for Physical Activity Questionnaire have been used to determine ADL and adequacy towards physical activity, respectively. The PERF-FIT has been used to measure motor skill related fitness levels. RESULTS: Large group differences (p = 0.001) were found for ADL and all domains of self-efficacy between TD and DCD children. However, ADL and self-efficacy were not different between moderate and severe DCD. Motor skill related fitness was significantly lower (p = 0.01) for children with DCD than TD children, and between children with moderate and severe DCD. The relation between self-efficacy and DCDDaily-Q was different in the two DCD groups. Slow motor learning was associated with lower perceived enjoyment in physical education in the moderate DCD group, and with lower perceived adequacy in physical education in the severe DCD group. CONCLUSIONS: Children with DCD participate and enjoy physical activity less than their peers. This combination of lower participation, lower predilection to physical activity and lowered motor skill-related fitness is a concern for the present and future health status of children with DCD.

The relationship between screen time and gross motor movement: A cross-sectional study of pre-school aged left-behind children in China.

OBJECTIVE: To investigate the level of screen time and gross motor movement level and the correlation between them in left-behind children aged 3 to 6 years old in China. METHODS: A randomized whole-group sampling method was used to study 817 left-behind children aged 3-6 years in 15 kindergartens in Xiangcheng city, Henan province. The third version of the Test of Gross Motor Development (TGMD-3) was used to test the children's gross motor movement level, and the screen time questionnaire was used to test the children's screen time level. The relationship between the two and the indicators was explored using Pearson's two-sided correlation and multilevel regression. RESULTS: The average daily screen time of left-behind children aged 3-6 years old increased with age, and the reporting rate of >2 h/d ranged from 22.43% to 33.73%; gross motor movement of left-behind children aged 3-6 years old increased with age, with significant differences between age (p<0.05). There was a low to moderate negative correlation (r = -0.133 to -0.354, p<0.05) between screen time and gross motor movement in children aged 3-6 years, and multiple regression analysis showed that screen time was predictive of gross motor movement in children (p<0.05), with an explanation rate of 21.4%. CONCLUSION: There is a correlation between screen time and gross motor movement development in children aged 3-6 years old left behind, and the gross motor movement ability of children aged 3-6 years old can be developed by reducing screen time and increasing physical activity.

International study of 24-h movement behaviors of the early years (SUNRISE): A pilot study from Iran.

BACKGROUND: This study examined the proportion of Iranian children who met the World Health Organization (WHO) Guidelines for physical activity, sedentary behaviour and sleep for children under 5 years. Additionally, it investigated the feasibility and acceptability of the methods to be used in the SUNRISE study. METHODS: This pilot study was conducted among 83 children aged 3 and 4 years in preschools and health care centres in Iran, in 2022. Physical activity, sedentary behaviour and sleep (ActiGraph wGT3x-BT); fine and gross motor skills (validated activities); and executive functions (the Early Years Toolbox) were assessed. RESULTS: Only four (4.8%) children met all recommendations of the WHO guidelines. The proportion of children who met MVPA, TPA, screen time, restrained sitting and sleep were 44.6%, 38.6%, 19.3%, 38.6% and 65.1%, respectively. Fifty-two (62.6%) children wore the ActiGraph for at least three full days. A total of 97.6%, 95.1% and 91.5% of children completed anthropometric, EF and motor skill assessments, respectively. CONCLUSION: This pilot study was feasible and acceptable among Iranian children. Regarding the low proportion of children who met the WHO guidelines, it is recommended that long-term and practical strategies be developed to promote healthier lifestyles among preschool children in Iran.

The effect of proprioceptive neuromuscular facilitation on functional skills, muscle strength, and trunk control in children with cerebral palsy: A randomized controlled trial.

BACKGROUND: Proprioceptive neuromuscular facilitation (PNF) is generally used for the lower limbs in children with Cerebral Palsy (CP). This study aimed to determine the effect of PNF and Neurodevelopmental Therapy (NDT) on functional abilities, muscle strength, and trunk control in children with CP. METHODS: Thirty spastic CP children classified as either level I-II in the Gross Motor Function Classification System (GMFCS) or level I-II in the Manual Ability Classification System (MACS) were included. The PNF (n = 15) and the NDT group (n = 15) had physiotherapy for six weeks. The ABILHAND-Kids scale, the Purdue Pegboard Test (PBPT), the Nine-Hole Peg Test (9-HPT), and the Jebson-Taylor Hand Function Test (JTHFT) were employed. Pinch meters, Jamar handheld dynamometers, and digital muscular strength assessments were used. RESULTS: The PNF group increased shoulder flexion (p < 0.05), adduction (p < 0.05), elevation (p < 0.05), scapular abduction (p < 0.05), elbow extension (right) (p < 0.05), grip (p < 0.05), and pinch strengths (left p < 0.05, right p < 0.05). The PNF group had significantly lower 9-HPT (p < 0.05), JTHFT (card turning), JTHFT (simulated feeding), JTHFT (lifting light cans), and JTHFT (lifting weight cans) durations (p < 0.05), and significantly higher PBPT (right-left) PBPT (bimanual), PBPT (assembly). (p < 0.05), ABILHAND (p < 0.05), and TCMS total scores (p < 0.001). While JTHFT (simulated feeding-left), JTHFT (stacking checkers-left), JTHFT (lifting light cans-left), and JTHFT (lifting weight cans-right/left) (p < 0.05) durations decreased in the NDT group, PBPT (right) (p < 0.05) had an increase in duration. CONCLUSION: PNF improves trunk control, upper extremity functional skills, selective proximal muscle strength, and distal upper extremity muscle and grip strength.

Modulation of Neural Spiking in Motor Cortex-Cerebellar Networks during Sleep Spindles.

Sleep spindles appear to play an important role in learning new motor skills. Motor skill learning engages several brain regions with two important areas being the motor cortex (M1) and the cerebellum (CB). However, the neurophysiological processes in these areas during sleep, especially how spindle oscillations affect local and cross-region spiking, are not fully understood. We recorded an activity from the M1 and cerebellar cortex in eight rats during spontaneous activity to investigate how sleep spindles in these regions are related to local spiking as well as cross-region spiking. We found that M1 firing was significantly changed during both M1 and CB spindles, and this spiking occurred at a preferred phase of the spindle. On average, M1 and CB neurons showed most spiking at the M1 or CB spindle peaks. These neurons also developed a preferential phase locking to local or cross-area spindles with the greatest phase-locking value at spindle peaks; however, this preferential phase locking was not significant for cerebellar neurons when compared with CB spindles. Additionally, we found that the percentage of task-modulated cells in the M1 and CB that fired with nonuniform spike phase distribution during M1/CB spindle peaks were greater in the rats that learned a reach-to-grasp motor task robustly. Finally, we found that spindle band LFP coherence (for M1 and CB LFPs) showed a positive correlation with success rate in the motor task. These findings support the idea that sleep spindles in both the M1 and CB recruit neurons that participate in the awake task to support motor memory consolidation.

Applying the constraints-led approach to facilitate exploratory learning of the volleyball serve.

Exploration is an important feature for successfully learning motor skills. However, game rules such as one attempt to serve in volleyball could discourage exploration due to an individual's fear of making a mistake and forfeiting a point. The constraints-led approach is a coaching methodology that encourages exploration by selectively manipulating task constraints such as rules. Therefore, the aim of this study was to examine whether the addition of the task constraint of a second serve would encourage volleyball players to use their first serve to explore their action capabilities. Forty male high school students competed in two volleyball games; a regulation (single serve) game and a modified (2-serve) game. Participants reported that having a second chance at serving allowed them to feel more confident and relaxed which facilitated the exploration of their serving capability. In the 2-serve game, participants attempted a more powerful (M = 60.3 km/hr), and complex (M = 44.5% jump topspin serves) first serve, compared to the regulation game (M = 55.6 km/hr; M = 25.2% jump topspin serves). Findings suggest that to facilitate learning of motor skills, it is important to manipulate the practice environment using task constraints to address the factors that restrict exploration.

Effects of social isolation and galactic cosmic radiation on fine motor skills and behavioral performance.

Future NASA missions will require astronauts to travel farther and spend longer durations in space than ever before. This will also expose astronauts to longer periods of several physical and psychological challenges, including exposure to space radiation (SR) and periods of social isolation (SI), which could have unknown negative effects on physical and mental health. Each also has the potential to negatively impact sleep which can reduce the ability to cope with stressful experiences and lead to sensorimotor, neurocognitive, and physical deficits. The effects of SI and SR on gross motor performance has been shown to vary, and depend on, individual differences in stress resilience and vulnerability based on our established animal model in which stress produces different effects on sleep. In this study, the impact that SI and SR, either alone or together, had on fine motor skill performance (bilateral tactile adhesive removal task (BTAR)) was assessed in male rats. We also examined emotional, exploratory, and other off-task behavioral responses during testing and assessed whether sensorimotor performance and emotion varied with individual differences in resilience and vulnerability. BTAR task performance was differentially impacted by SI and SR, and were further influenced by the stress resilience/vulnerability phenotype of the rats. These findings further demonstrate that identifying individual responses to stressors that can impact sensorimotor ability and behavior necessary to perform mission-related tasks will be of particular importance for astronauts and future missions. Should similar effects occur in humans, there may be considerable inter-individual variability in the impact that inflight stressors have on astronauts and their ability to perform mission-related tasks.

Post-Stroke Impairments of Manual Dexterity and Finger Proprioception: Their Contribution to Upper Limb Activity Capacity.

BACKGROUND: Knowing how impaired manual dexterity and finger proprioception affect upper limb activity capacity is important for delineating targeted post-stroke interventions for upper limb recovery. OBJECTIVES: To investigate whether impaired manual dexterity and finger proprioception explain variance in post-stroke activity capacity, and whether they explain more variance than conventional clinical assessments of upper limb sensorimotor impairments. METHODS: Activity capacity and hand sensorimotor impairments were assessed using clinical measures in N = 42 late subacute/chronic hemiparetic stroke patients. Dexterity was evaluated using the Dextrain Manipulandum to quantify accuracy of visuomotor finger force-tracking (N = 36), timing of rhythmic tapping (N = 36), and finger individuation (N = 24), as well as proprioception (N = 27). Stepwise multivariate and hierarchical linear regression models were used to identify impairments best explaining activity capacity. RESULTS: Dexterity and proprioceptive components significantly increased the variance explained in activity capacity: (i) Box and Block Test was best explained by baseline tonic force during force-tracking and tapping frequency (adjusted R2 = .51); (ii) Motor Activity Log was best explained by success rate in finger individuation (adjusted R2 = .46); (iii) Action Research Arm Test was best explained by release of finger force and proprioceptive measures (improved reaction time related to use of proprioception; adjusted R2 = .52); and (iv) Moberg Pick-Up test was best explained by proprioceptive function (adjusted R2 = .18). Models excluding dexterity and proprioception variables explained up to 19% less variance. CONCLUSIONS: Manual dexterity and finger proprioception explain unique variance in activity capacity not captured by conventional impairment measures and should be assessed when considering the underlying causes of post-stroke activity capacity limitations.URL: https://www.clinicaltrials.gov. Unique identifier: NCT03934073.

Reach-to-Grasp and tactile discrimination task: A new task for the study of sensory-motor learning.

Although active touch in rodents arises from the forepaws as well as whiskers, most research on active touch only focuses on whiskers. This results in a paucity of tasks designed to assess the process of active touch with a forepaw. We develop a new experimental task, the Reach-to-Grasp and Tactile Discrimination task (RGTD task), to examine active touch with a forepaw in rodents, particularly changes in processes of active touch during motor skill learning. In the RGTD task, animals are required to (1) extend their forelimb to an object, (2) grasp the object, and (3) manipulate the grasped object with the forelimb. The animals must determine the direction of the manipulation based on active touch sensations arising during the period of the grasping. In experiment 1 of the present study, we showed that rats can learn the RGTD task. In experiment 2, we confirmed that the rats are capable of reversal learning of the RGTD task. The RGTD task shared most of the reaching movements involved with conventional forelimb reaching tasks. From the standpoint of a discrimination task, the RGTD task enables rigorous experimental control, for example by removing bias in the stimulus-response correspondence, and makes it possible to utilize diverse experimental procedures that have been difficult in prior tasks.