scholarly journals Reorganization of functional and directed corticomuscular connectivity during precision grip from childhood to adulthood

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikkel Malling Beck ◽  
Meaghan Elizabeth Spedden ◽  
Jesper Lundbye-Jensen

AbstractHow does the neural control of fine movements develop from childhood to adulthood? Here, we investigated developmental differences in functional corticomuscular connectivity using coherence analyses in 111 individuals from four different age groups covering the age range 8–30 y. EEG and EMG were recorded while participants performed a uni-manual force-tracing task requiring fine control of force in a precision grip with both the dominant and non-dominant hand. Using beamforming methods, we located and reconstructed source activity from EEG data displaying peak coherence with the EMG activity of an intrinsic hand muscle during the task. Coherent cortical sources were found anterior and posterior to the central sulcus in the contralateral hemisphere. Undirected and directed corticomuscular coherence was quantified and compared between age groups. Our results revealed that coherence was greater in adults (20–30 yo) than in children (8–10 yo) and that this difference was driven by greater magnitudes of descending (cortex-to-muscle), rather than ascending (muscle-to-cortex), coherence. We speculate that the age-related differences reflect maturation of corticomuscular networks leading to increased functional connectivity with age. We interpret the greater magnitude of descending oscillatory coupling as reflecting a greater degree of feedforward control in adults compared to children. The findings provide a detailed characterization of differences in functional sensorimotor connectivity for individuals at different stages of typical ontogenetic development that may be related to the maturational refinement of dexterous motor control.

2004 ◽  
Vol 16 (8) ◽  
pp. 1339-1351 ◽  
Author(s):  
Kathleen M. Thomas ◽  
Ruskin H. Hunt ◽  
Nathalie Vizueta ◽  
Tobias Sommer ◽  
Sarah Durston ◽  
...  

Prevailing theories of implicit or unaware learning propose a developmental invariance model, with implicit function maturing early in infancy or childhood despite prolonged improvements in explicit or intentional learning and memory systems across childhood. Neuroimaging studies of adult visuomotor sequence learning have associated fronto-striatal brain regions with implicit learning of spatial sequences. Given evidence of continued development in these brain regions during childhood, we compare implicit sequence learning in adults and 7- to 11-year-old children to examine potential developmental differences in the recruitment of fronto-striatal circuitry during implicit learning. Participants performed a standard serial reaction time task. Stimuli alternately followed a fixed 10-step sequence of locations or were presented in a pseudorandom order of locations. Adults outperformed children, achieving a significantly larger sequence learning effect and showing learning more quickly than children. Age-related differences in activity were observed in the premotor cortex, putamen, hippocampus, inferotemporal cortex, and parietal cortex. We observed differential recruitment of cortical and subcortical motor systems between groups, presumably reflecting age differences in motor response execution. Adults showed greater hippocampal activity for sequence trials, whereas children demonstrated greater signal during random trials. Activity in the right caudate correlated significantly with behavioral measures of implicit learning for both age groups, although adults showed greater signal change than children overall, as would be expected given developmental differences in sequence learning magnitude. These results challenge the idea of developmental invariance in implicit learning and instead support a view of parallel developments in implicit and explicit learning systems.


2016 ◽  
Vol 115 (3) ◽  
pp. 1605-1619 ◽  
Author(s):  
Neha Uppal ◽  
John J. Foxe ◽  
John S. Butler ◽  
Frantzy Acluche ◽  
Sophie Molholm

Young children are often hyperreactive to somatosensory inputs hardly noticed by adults, as exemplified by irritation to seams or labels in clothing. The neurodevelopmental mechanisms underlying changes in sensory reactivity are not well understood. Based on the idea that neurodevelopmental changes in somatosensory processing and/or changes in sensory adaptation might underlie developmental differences in somatosensory reactivity, high-density electroencephalography was used to examine how the nervous system responds and adapts to repeated vibrotactile stimulation over childhood. Participants aged 6–18 yr old were presented with 50-ms vibrotactile stimuli to the right wrist over the median nerve at 5 blocked interstimulus intervals (ranging from ∼7 to ∼1 stimulus per second). Somatosensory evoked potentials (SEPs) revealed three major phases of activation within the first 200 ms, with scalp topographies suggestive of neural generators in contralateral somatosensory cortex. Although overall SEPs were highly similar for younger, middle, and older age groups (6.1–9.8, 10.0–12.9, and 13.0–17.8 yr old), there were significant age-related amplitude differences in initial and later phases of the SEP. In contrast, robust adaptation effects for fast vs. slow presentation rates were observed that did not differ as a function of age. A greater amplitude response in the later portion of the SEP was observed for the youngest group and may be related to developmental changes in responsivity to somatosensory stimuli. These data suggest the protracted development of the somatosensory system over childhood, whereas adaptation, as assayed in this study, is largely in place by ∼7 yr of age.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256109
Author(s):  
Leslie Rollins ◽  
Erin Bertero ◽  
Laurie Hunter

The aim of the present research was to assess age-related differences in how children and adults interpret and visually process emotionally ambiguous neutral faces. Children and adults provided neutral child faces with valence and arousal ratings while eye movements were recorded. Consistent with previous research, children and adults both interpreted the neutral faces as negatively valenced. Both age groups showed fewer fixations to the eye region when they rated the faces as positive. However, adults fixated more on the eye region when they rated the faces as negative whereas children fixated more on the eye region when they rated the faces as neutral. This finding may suggest that children strategically allocate attentional resources to the eye region when processing emotionally ambiguous faces to gather critical affective information. These findings have implications for the utilization of neutral faces as an experimental control condition and serve as the foundation for future research on the development of mechanisms that underlie the interpretation of emotionally ambiguous faces.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Mikkel Malling Beck ◽  
Meaghan Elizabeth Spedden ◽  
Martin J Dietz ◽  
Anke Ninija Karabanov ◽  
Mark Schram Christensen ◽  
...  

Human dexterous motor control improves from childhood to adulthood, but little is known about the changes in cortico-cortical communication that support such ontogenetic refinement of motor skills. To investigate age-related differences in connectivity between cortical regions involved in dexterous control we analyzed electroencephalographic data from 88 individuals (range 8-30y) performing a visually-guided precision grip task using Dynamic Causal Modelling (DCM) and Parametric Empirical Bayes (PEB). Our results demonstrate that bidirectional coupling in a canonical 'grasping network' is associated with precision grip performance across age groups. We further demonstrate greater backward coupling from higher-order to lower-order sensorimotor regions from late adolescence in addition to differential associations between connectivity strength in a premotor-prefrontal network and motor performance for different age groups. We interpret these findings as reflecting greater use of top-down and executive control processes with development. These results expand our understanding of the cortical mechanisms that support dexterous abilities through development.


2020 ◽  
Author(s):  
Mikkel Malling Beck ◽  
Meaghan Elizabeth Spedden ◽  
Jesper Lundbye-Jensen

AbstractHow does the neural control of manual movements mature from childhood to adulthood? Here, we investigated developmental differences in functional corticomuscular connectivity using coherence techniques in 91 individuals recruited from four different age groups covering the age range 8-30y. EEG and EMG were recorded while participants performed a unimanual visual force-tracing task requiring fine control of the force produced in a precision grip with both the dominant and non-dominant hand. Using beamforming methods, we reconstructed source activity from EEG data displaying peak coherence with the active FDI muscle during the task in order to assess functional corticomuscular connectivity. Our results revealed that coherence was greater in adolescents and adults than in children and that the difference in coherence between children and adults was driven by a greater magnitude of descending (cortex-to-muscle) coherence. This was paralleled by the observation of a posterior-to-anterior shift in the cortical sources displaying corticomuscular coherence within the contralateral hemisphere from late adolescence. Finally, we observed that corticomuscular coherence was higher on the non-dominant compared to the dominant hand across age groups. These findings provide a detailed characterization of differences in task-related corticomuscular connectivity for individuals at different stages of typical ontogenetic development that may be related to the maturational refinement of dexterous motor control.Key points‐Fine motor control is gradually refined during human motor development, but little is known about the underlying neurophysiological mechanisms.‐Here, we used EEG and EMG to investigate functional corticomuscular connectivity during a precision grip with the dominant and non-dominant hand in 91 typically developed children, adolescents and adults (age range 8-30y).‐We show that older adolescents and adults are characterized by greater levels of corticomuscular coherence compared to children and that this is mainly driven by greater magnitudes of descending coherence (cortex-to-muscle). This is paralleled by a more anterior cortical site of coherence in older adolescents and adults compared to younger individuals.‐These results help us better understand the ontogenetic development of task-related functional connectivity in sensorimotor networks.


2013 ◽  
Vol 18 (3) ◽  
pp. 158-168 ◽  
Author(s):  
Emily Frankenberg ◽  
Katharina Kupper ◽  
Ruth Wagner ◽  
Stephan Bongard

This paper reviews research on young migrants in Germany. Particular attention is given to the question of how Germany’s history of migration, immigration policies, and public attitude toward migrants influence the transcultural adaptation of children and adolescents from different ethnic backgrounds. We combine past research with the results of new empirical studies in order to shed light on migrants’ psychological and sociocultural adaptation. Studies comparing young migrants and their German peers in terms of psychological well-being, life satisfaction, and mental health outcome suggest higher rates of emotional and behavioral problems among migrants of most age groups. With regard to adolescent populations between the ages of 14 and 17 years, however, the existence of differences between migrants and natives appears to be less clear. Research has also yielded inconsistent findings regarding the time trajectory of transcultural adaptation among adolescents. The coincidence of acculturation and age-related change is discussed as a possible source of these inconsistencies. Further, we provide an overview of risk and protective factors such as conflicting role expectations and ethnic discrimination, which may cause heightened vulnerability to adverse adaptation outcomes in some groups. Large-scale studies have repeatedly shown migrants of all age groups to be less successful within the German school system, indicating poor sociocultural adaptation. Possible explanations, such as the idiosyncrasies of the German school system, are presented. Our own studies contribute to the understanding of young migrants’ adaptation process by showing that it is their orientation to German culture, rather than the acculturation strategy of integration, that leads to the most positive psychological and sociocultural outcomes. The paper concludes by discussing implications for future cross-cultural research on young migrants and by suggesting recommendations for multicultural policies.


Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.


1970 ◽  
Vol 4 (2) ◽  
pp. 74-77
Author(s):  
Rukshana Ahmed ◽  
Shamim Ara

Pathological changes in the prostate gland occur commonly with advancing age including inflammation, atrophy, hyperplasia and carcinoma and a change in volume is also evident. Estimation of volume of prostate may be useful in a variety of clinical settings. A cross-sectional descriptive study was designed to see the changes in volume of the prostate with advancing age and done in the Department of Anatomy, Dhaka Medical College, Dhaka from August 2006 to June 2007. The study was performed on 70 post-mortem human prostates collected from the unclaimed dead bodies that were under examination in the Department of Forensic Medicine, Dhaka Medical College, Dhaka. The samples were divided into three age groups; group A (10-20 years), group B (21-40 years) and group C (41-70 years). Volume of the sample was measured by using the ellipsoid formula. The mean ± SD volume of prostate was 7.68 ± 3.64 cm3 in group A, 10.61 ± 3.99 cm3 in group B and 15.40 ± 6.31 cm3 in group C. Mean difference in volume between group A and group C, group B and group C were statistically significant (p<0.001). Statistically significant positive correlation was found between age and volume of prostate (r = + 0.579, p < 0.001). Key Words: Prostate; volume; Bangladeshi. DOI: 10.3329/imcj.v4i2.6501Ibrahim Med. Coll. J. 2010; 4(2): 74-77


2019 ◽  
Vol 1 (8) ◽  
pp. 42-50
Author(s):  
A. V. Budkevich ◽  
L. B. Ivanov ◽  
G. R. Novikova ◽  
G. M. Dzhanumova

According to the authors, rationing the age-related EEG parameters in children should be based on personal psychical characteristics. A comparative analysis of personal psychical characteristics and electroencephalographic data was carried out in 300 apparently healthy children aged 3-15 years. According to this principle, two subgroups of conditionally healthy children in each age group were singled out: 1) with an immature attention function and 2) with an increased anxious background that do not reach the pathological level. Registration and analysis of EEG was performed by the Neurokariograf computer complex (MBN, Moscow) using mathematical processing methods.The EEG interpretation was based on the principle of assessing the functional state of a child's brain using a three-component model according to: 1) wakefulness level and its dissociation, 2) severity of signs of the EEG neurotic pattern, 3) directionality of formation of traits of the system-functional brain organization (severity of signs functional hypofrontality).lt was found the presence of EEG signs was indicative of a lower level of wakefulness in children with an immature function of attention in all age groups, compared with the indicators of the average population of group and children with an increased background of anxiety. Children with an increased background of anxiety have a tendency to prevalence and excessive spatial synchronization of the alpha rhythm. ln healthy children, the fact of a decrease in wakefulness and the presence of signs of anxiety in the clinic and in EEG patterns indicates individual personalities and should not be considered as pathology.


Author(s):  
Khuan Seow ◽  
Nadia Caidi

Canada has an aging population with the fastest growing age groups (80 and 45-64 years old) vulnerable to age-related diseases such as Alzheimer’s disease. Caregiving responsibilities often fall to the family members of the afflicted without much attention and consideration being placed on the information needs of these caregivers. We call for a better understanding of these caregivers' information needs and uses by social policy makers as well as information providers.La population du Canada a tendance à vieillir considérablement, avec la hausse la plus rapide dans les groupes d’âge (80 et 45 à 64 ans). Les personnes âges sont très vulnérables à toute sorte de maladies, telles que la maladie d’Alzheimer. La responsabilité revient souvent aux membres de la famille qui doivent prendre soin des personnes atteintes de cette maladie. Or, nous ne connaissons que peu de chose sur les besoins en information des personnes qui prennent soin de ces malades de l’Alzheimer : qui sont-ils ? Quelles sont leurs sources... 


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