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Motor issues are frequently observed accompanying core deficits in autism spectrum disorder (ASD). Impaired motor behavior has also been linked to cognitive and social abnormalities, and problems with predictive ability have been suggested to play an important, possibly shared, part across all these domains. Brain imaging of sensory-motor behavior is a promising method for characterizing the neurobiological foundation for this proposed key trait. The present functional magnetic resonance imaging (fMRI) developmental study, involving children/youth with ASD, typically developing (TD) children/youth, and neurotypical adults, will investigate brain activations during execution and observation of a visually guided, goal-directed sequential (two-step) manual task. Neural processing related to both execution and observation of the task, as well as activation patterns during the preparation stage before execution/observation will be investigated. Main regions of interest include frontoparietal and occipitotemporal cortical areas, the human mirror neuron system (MNS), and the cerebellum.
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Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Criança , Encéfalo/fisiopatologia , Encéfalo/diagnóstico por imagem , Masculino , Adolescente , Feminino , Adulto , Mapeamento Encefálico/métodos , Transtorno do Espectro Autista/fisiopatologia , Transtorno do Espectro Autista/diagnóstico por imagem , Movimento/fisiologia , Transtorno Autístico/fisiopatologia , Adulto Jovem , Desempenho Psicomotor/fisiologia , Neurônios-Espelho/fisiologiaRESUMO
BACKGROUND: The functional integration of the jaw and neck motor systems, of great importance to everyday oral activities, is established in early childhood. Detailed characterisation of this developmental progress is largely unknown. OBJECTIVE: To establish developmental changes in jaw-neck motor function in children over the ages 6-13 years compared to adults. METHODS: Jaw and head movement kinematics during jaw opening-closing and chewing were longitudinally recorded in 20 Swedish children (8 girls) at 6 (6.3 ± 0.4), 10 (10.3 ± 0.3) and 13 (13.5 ± 0.7) years of age and 20 adults (9 women, 28.2 ± 6.7). Movement amplitudes, jaw movement cycle time (CT), coefficient of variation (CV) and head/jaw ratio for amplitudes were analysed. Linear mixed effect analysis and Welch's t-test were used. RESULTS: Children showed pronounced movement variability and longer CT at 6 and 10 years old during opening and chewing (p < .001). Compared to adults, 6-year-olds showed higher head/jaw ratios (p < .02) and longer CT (p < .001) during opening and chewing, and higher CV-head (p < .001) during chewing. Whereas 10-year-olds showed larger jaw and head amplitudes (p < .02) and longer CT (p < .001) during opening, and longer CT (p < .001) and higher CV-head (p < .001) during chewing. For 13-year-olds, longer CT (p < .001) during chewing was found. CONCLUSION: Children showed pronounced movement variability and longer movement cycle time at 6-10 years and developmental progress in jaw-neck integration from 6 to 13 years, with 13-year-olds displaying adult-like movements. These results add new detailed understanding to the typical development of integrated jaw-neck motor function.
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Mandíbula , Músculos do Pescoço , Adulto , Humanos , Feminino , Criança , Pré-Escolar , Adulto Jovem , Fenômenos Biomecânicos , Estudos Longitudinais , Movimentos da Cabeça , Movimento , Mastigação , Arcada OsseodentáriaRESUMO
Autism spectrum disorder (ASD) is a diagnosis based on social communication deficits and prevalence of repetitive stereotyped behaviors, but sensorimotor disturbances are commonly exhibited. This longitudinal study aimed at exploring the development of the ability to form mental motor representations (motor imagery; MI) in 14 children with ASD and 17 typically developing (TD) children at 7, 8 and 9 years of age. MI was investigated using a hand laterality paradigm from which response times (RT) and error rates were extracted and compared with performance on a visually based mental rotation task (VI). A criterion task was used to ensure that the children could perform the task. The results showed wide performance variability in the ASD group with more failures than TD in the MI criterion task, especially at 7 years. For all age levels and both the MI and VI tasks, the error rates were significantly higher and RTs longer for the ASD group compared with TD. Signs of MI strategies were however noted in the ASD group as biomechanically constrained orientations had longer RTs than less constrained orientations, a RT pattern that differed from the VI task. The presence of MI in the ASD group was most evident at 9 years, but the error rates remained high at all ages, both in the MI and VI task. In comparison, the TD group showed stable MI strategies at all ages. These findings indicate that MI ability is delayed and/or impaired in children with ASD which may be related to difficulties performing required mental rotations.
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AIM: The neurocognitive basis of Developmental Coordination Disorder (DCD; or motor clumsiness) remains an issue of continued debate. This combined systematic review and meta-analysis provides a synthesis of recent experimental studies on the motor control, cognitive, and neural underpinnings of DCD. METHODS: The review included all published work conducted since September 2016 and up to April 2021. One-hundred papers with a DCD-Control comparison were included, with 1,374 effect sizes entered into a multi-level meta-analysis. RESULTS: The most profound deficits were shown in: voluntary gaze control during movement; cognitive-motor integration; practice-/context-dependent motor learning; internal modeling; more variable movement kinematics/kinetics; larger safety margins when locomoting, and atypical neural structure and function across sensori-motor and prefrontal regions. INTERPRETATION: Taken together, these results on DCD suggest fundamental deficits in visual-motor mapping and cognitive-motor integration, and abnormal maturation of motor networks, but also areas of pragmatic compensation for motor control deficits. Implications for current theory, future research, and evidence-based practice are discussed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, identifier: CRD42020185444.
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BACKGROUND: Atypical motor functioning is prevalent in children with autism spectrum disorder (ASD). Knowledge of the underlying kinematic properties of these problems is sparse. AIMS: To investigate characteristics of manual motor planning and performance difficulties/diversity in children with ASD by detailed kinematic measurements. Further, associations between movement parameters and cognitive functions were explored. METHODS AND PROCEDURES: Six-year-old children with ASD (N = 12) and typically developing (TD) peers (N = 12) performed a sequential manual task comprising grasping and fitting a semi-circular peg into a goal-slot. The goal-slot orientation was manipulated to impose different motor planning constraints. Movements were recorded by an optoelectronic system. OUTCOMES AND RESULTS: The ASD-group displayed less efficient motor planning than the TD-group, evident in the reach-to-grasp and transport kinematics and less proactive adjustments of the peg to the goal-slot orientations. The intra-individual variation of movement kinematics was higher in the ASD-group compared to the TD-group. Further, in the ASD-group, movement performance associated negatively with cognitive functions. CONCLUSIONS AND IMPLICATIONS: Planning and execution of sequential manual movements proved challenging for children with ASD, likely contributing to problems in everyday actions. Detailed kinematic investigations contribute to the generation of specific knowledge about the nature of atypical motor performance/diversity in ASD. This is of potential clinical relevance.
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Transtorno do Espectro Autista , Fenômenos Biomecânicos , Criança , Objetivos , Força da Mão , Humanos , MovimentoRESUMO
BACKGROUND: We previously reported results from a randomized controlled trial in which we found that Swedish infants consuming an experimental low-energy, low-protein formula (EF) supplemented with bovine milk fat globule membranes (MFGMs) until 6 mo of age had several positive outcomes, including better performance in the cognitive domain of Bayley Scales of Infant and Toddler Development 3rd Edition at 12 mo of age, and higher plasma cholesterol concentrations during the intervention, than infants consuming standard formula (SF). OBJECTIVES: We aimed to evaluate neurodevelopment, growth, and plasma cholesterol status at 6 and 6.5 y of age in the same study population. METHODS: We assessed cognitive and executive functions using the Wechsler Intelligence Scale for Children 4th Edition (WISC-IV), Brown Attention-Deficit Disorder Scales for Children and Adolescents (Brown-ADD), and Quantified Behavior (Qb) tests, and behavior using the Child Behavior Checklist (CBCL) and Teacher's Report Form (TRF), at 6.5 y of age. Anthropometrics and plasma lipids were assessed at 6 y of age. RESULTS: There were no differences between the EF and SF groups in any of the subscales in WISC-IV or Brown-ADD at 6.5 y of age, in the proportion of children with scores outside the normal range in the Qb test, nor in clinical or borderline indications of problems in adaptive functioning from parental and teacher's scoring using the CBCL and TRF. There were no differences between the EF and SF groups in weight, length, or head or abdominal circumferences, nor in plasma concentrations of homocysteine, lipids, insulin, or glucose. CONCLUSIONS: Among children who as infants consumed a low-energy, low-protein formula supplemented with bovine MFGMs, there were no effects on neurodevelopment, growth, or plasma cholesterol status 6-6.5 y later.
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Desenvolvimento Infantil , Dieta com Restrição de Proteínas , Suplementos Nutricionais , Ingestão de Energia , Glicolipídeos/administração & dosagem , Glicoproteínas/administração & dosagem , Fórmulas Infantis , Animais , Bovinos , Criança , Feminino , Seguimentos , Humanos , Gotículas Lipídicas , Masculino , NeurogêneseRESUMO
This study aimed to investigate cognitive and behavioral outcomes in relation to gestational age (GA) in school-aged children born preterm (PT). Results from the Wechsler Intelligence Scale for Children, 4th edition (WISC-IV), and the Child Behavior Checklist (CBCL) were analyzed in 51 children (mean age: 7.8 years [range: 7.0-8.7]) born PT (mean GA: 31 weeks [range: 23-35]; birth weight, mean: 1,637 g [range: 404-2,962]) with the majority (96%) having no diagnosed cognitive, sensory, or motor impairments. The control group included 57 age-matched typically developing children (mean age: 7.9 years [range: 6.2-8.7]) born full-term (FT). Children born PT, extremely PT (GA < 28) in particular, showed significantly lower cognitive performance and higher behavioral problem scores compared with children born FT. GA was found to predict aspects of both cognitive functioning and behavioral problems within the PT group, with lower GA being related to both poorer cognitive outcomes and elevated affective and attention-deficit/hyperactivity problems. Global cognitive functioning did not independently predict aspects of behavioral outcomes. Findings demonstrate that, even in children born PT without severe perinatal and/or postnatal complications and receiving active perinatal care, a short gestation is an evident risk factor for long-term negative effects on mental health independent of cognitive functioning. Additional findings suggest that both reduced growth and lower parental educational level may contribute to increased risk for poorer cognitive and behavioral functioning in children born PT.
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BACKGROUND: Autism spectrum disorder (ASD) evolves from an interplay between genetic and environmental factors during prenatal development. Since identifying maternal biomarkers associated with ASD risk in offspring during early pregnancy might result in new strategies for intervention, we investigated maternal metabolic biomarkers in relation to occurrence of ASD in offspring using both univariate logistic regression and multivariate network analysis. METHODS: Serum samples from 100 women with an offspring diagnosed with ASD and 100 matched control women with typically developing offspring were collected at week 14 of pregnancy. Concentrations of 62 metabolic biomarkers were determined, including amino acids, vitamins (A, B, D, E, and K), and biomarkers related to folate (vitamin B9) metabolism, lifestyle factors, as well as C-reactive protein (CRP), the kynurenine-tryptophan ratio (KTR), and neopterin as markers of inflammation and immune activation. RESULTS: We found weak evidence for a positive association between higher maternal serum concentrations of folate and increased occurrence of ASD (OR per 1 SD increase: 1.70, 95% CI 1.22-2.37, FDR adjusted P = 0.07). Multivariate network analysis confirmed expected internal biochemical relations between the biomarkers. Neither inflammation markers nor vitamin D3 levels, all hypothesized to be involved in ASD etiology, displayed associations with ASD occurrence in the offspring. CONCLUSIONS: Our findings suggest that high maternal serum folate status during early pregnancy may be associated with the occurrence of ASD in offspring. No inference about physiological mechanisms behind this observation can be made at the present time because blood folate levels may have complex relations with nutritional intake, the cellular folate status and status of other B-vitamins. Therefore, further investigations, which may clarify the potential role and mechanisms of maternal blood folate status in ASD risk and the interplay with other potential risk factors, in larger materials are warranted.
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Transtorno do Espectro Autista/epidemiologia , Ácido Fólico/sangue , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Mães , Gravidez/sangue , Primeiro Trimestre da Gravidez/sangueRESUMO
In everyday behavior, we perform numerous goal-directed manual tasks that contain a sequence of actions. However, knowledge is limited regarding developmental aspects of predictive control mechanisms in such tasks, particularly with regard to brain activations supporting sequential manual actions in children. We investigated these issues in typically developing children at early adolescence (11-14 years) compared with previously collected data from adults. While lying in a magnetic resonance imaging (MRI) scanner, the participants steered a cursor on a computer screen towards sequentially presented targets using a hand-held manipulandum. The next target was either revealed after completion of the ongoing target (one-target condition), in which case forthcoming movements could not be planned ahead, or displayed in advance (two-target condition), which allowed the use of a predictive control strategy. The adults completed more targets in the two- than one-target condition, displaying an efficient predictive control strategy. The children, in contrast, completed fewer targets in the two- than one-target condition, and difficulties implementing a predictive strategy were found due to a limited capacity to inhibit premature movements. Brain areas with increased activation in children, compared with the adults, included prefrontal and posterior parietal regions, suggesting an increased demand for higher-level cognitive processing in the children due to inhibitory challenges. Thus, regarding predictive mechanisms during sequential manual tasks, crucial development likely occurs beyond early adolescence. This is at a later age than what has previously been reported from other manual tasks, suggesting that predictive phase transitions are difficult to master.
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Desenvolvimento do Adolescente/fisiologia , Mapeamento Encefálico , Desenvolvimento Infantil/fisiologia , Função Executiva/fisiologia , Inibição Psicológica , Atividade Motora/fisiologia , Lobo Parietal/fisiologia , Córtex Pré-Frontal/fisiologia , Desempenho Psicomotor/fisiologia , Adolescente , Criança , Feminino , Mãos/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Parietal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagemRESUMO
This study explored age-related differences in motor planning as expressed in arm-hand kinematics during a sequential peg moving task with varying demands on goal insertion complexity (second-order planning). The peg was a vertical cylinder with either a circular or semicircular base. The task was to transport the peg between two positions and rotate it various amounts horizontally before fitting into its final position. The amount of rotation required was either 0°, 90°, 180°, or -90°. The reaching for the peg, the displacement of it, and the way the rotation was accomplished was analyzed. Assessments of end state comfort, goal interpretation errors, and type of grip used were also included. Participants were two groups of typically developing children, one younger (Mage = 6.7 years) and one older (Mage = 10.3 years), and one adult group (Mage = 34.9 years). The children, particularly 6-year-olds, displayed less efficient prehensile movement organization than adults. Related to less efficient motor planning, 6-year-olds, mainly, had shorter reach-to-grasp onset latencies, higher velocities, and shorter time to peak velocities, and longer grasp durations than adults. Importantly, the adults rotated the peg during transport. In contrast, the children made corrective rotations after the hand had arrived at the goal.
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Fenômenos Biomecânicos/fisiologia , Desenvolvimento Infantil/fisiologia , Função Executiva/fisiologia , Atividade Motora/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Fatores Etários , Criança , Feminino , Humanos , MasculinoRESUMO
Covering a 20-year period of work with children with severe cerebral palsy (CP) within a Swedish habilitation service, changes in passive wrist extension with fingers extended (PWE-FE) and current hand function are described and compared between children receiving systematic upper-extremity treatment with botulinum neurotoxin type A and intervention programs from before 7 years of age (Group 1, n = 7), those whom for various reasons did not undergo this treatment (Group 2, n = 10), and those not having the option to receive treatment until later during childhood/adolescence (Group 3, n = 8). Group 3 showed more critical and less normal PWE-FE values for both wrists, and poorer hand function scores, particularly compared with Group 1. Findings cautiously suggest that repeated upper-extremity spasticity-reducing treatment and movement training/orthoses from an early age may help prevent critical loss of passive range of motion of the wrist joint flexion/extension and promote hand function development in children with severe CP.
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Toxinas Botulínicas Tipo A/uso terapêutico , Paralisia Cerebral/terapia , Terapia por Exercício/métodos , Fármacos Neuromusculares/uso terapêutico , Toxinas Botulínicas Tipo A/administração & dosagem , Paralisia Cerebral/patologia , Paralisia Cerebral/reabilitação , Criança , Pré-Escolar , Terapia Combinada , Feminino , Mãos/fisiopatologia , Humanos , Injeções Intramusculares , Masculino , Movimento , Espasticidade Muscular , Reabilitação Neurológica/métodos , Fármacos Neuromusculares/administração & dosagem , Aparelhos Ortopédicos , Índice de Gravidade de DoençaRESUMO
In Parkinson's disease (PD), the fronto-striatal network is involved in motor and cognitive symptoms. Working memory (WM) updating training engages this network in healthy populations, as observed by improved cognitive performance and increased striatal BOLD signal. This two-part study aimed to assess the feasibility of WM updating training in PD and measure change in cognition, movement and functional brain response in one individual with PD after WM updating training. A feasibility and single-subject (FL) study were performed in which patients with PD completed computerized WM updating training. The outcome measures were the pre-post changes in criterion and transfer cognitive tests; cognitive complaints; psychological health; movement kinematics; and task-related BOLD signal. Participants in the feasibility study showed improvements on the criterion tests at post-test. FL displayed the largest improvements on the criterion tests and smaller improvements on transfer tests. Furthermore, FL reported improved cognitive performance in everyday life. A shorter onset latency and smoother upper-limb goal-directed movements were measured at post-test, as well as increased activation within the striatum and decreased activation throughout the fronto-parietal WM network. This two-part study demonstrated that WM updating training is feasible to complete for PD patients and that change occurred in FL at post-test in the domains of cognition, movement and functional brain response.
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Most everyday manual tasks, like grabbing a cup of coffee to drink, are comprised of a sequence of action phases. Efficient phase transitions, or linking, are achieved using a predictive control policy where motor commands for the next phase are specified and released in anticipation of sensory confirmation of goal completion of the current phase. If there is a discrepancy between predicted and actual sensory feedback about goal completion, corrective actions are employed to complete the current action phase before proceeding to the next. However, we lack understanding about brain activations supporting such predictive linking and corrective actions in manual tasks. In this study, during 3-T MRI-scanning, sixteen participants (5 males, 11 females; mean age 27.3 years, range 23-37) performed a sequential manual task, with or without the possibility for predictive linking. We found that predictive linking of action phases was associated with increased activation in a network that included right-sided fronto-parietal areas related to visuospatial attention, eye movements and motor planning, left-sided parietal areas related to implicit timing and shifts of motor attention, occipital regions bilaterally reflecting visual processing related to the attended next target, and finally, the anterior midcingulate cortex involved in continuous performance monitoring. Corrective actions were associated with increased activation in the left dorsolateral prefrontal cortex involved in reestablishing executive control over previously automatized behavior.
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Encéfalo/fisiologia , Desempenho Psicomotor/fisiologia , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Adulto JovemRESUMO
This study investigated developmental changes and differences in upper-limb movement organization from 4 to 8 years of age in children born preterm (PT) and fullterm (FT). Kinematic recordings of precision-demanding unimanual movements and lateral assessments were carried out in 37 children (18 PT). All children, particularly children born PT, displayed considerable gain in movement kinematics. Contrary to controls, children born PT displayed persistently less-evident side preference. Gestational age (GA) contributed significantly to kinematic differences shown, with larger upper-limb deviances in the lowest GAs, in agreement with cross-sectional findings of altered hemispheric connections and delayed side-specialization among children born very PT.
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Fenômenos Biomecânicos/fisiologia , Deficiências do Desenvolvimento/etiologia , Extremidade Superior/crescimento & desenvolvimento , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Estudos Longitudinais , Masculino , MovimentoRESUMO
Altered white matter microstructure is commonly found in children born preterm (PT), especially those born at an extremely low gestational age (GA). These children also commonly show disturbed motor function. This study explores the relation between white matter alterations and upper-limb movement segmentation in 41 children born PT (19 girls), and 41 children born at term (18 girls) at 8 years. The PT group was subdivided into extremely PT (E-PT; GA = 25-27 weeks, N = 10), very PT (V-PT; GA = 28-32 weeks, N = 13), and moderately PT (M-PT; GA = 33-35 weeks, N = 18). Arm/hand preference (preferred/non-preferred) was determined through object interactions and the brain hemispheres were designated accordingly. White matter alterations were assessed using diffusion tensor imaging in nine areas, and movement segmentation of the body-parts head, shoulder, elbow, and wrist were registered during a unimanual goal-directed task. Increased movement segmentation was demonstrated consistently on the preferred side in the E-PT group compared with the term born group. Also compared with the term born peers, the E-PT group demonstrated reduced fractional anisotropy (FA) in the cerebral peduncle (targeting the corticospinal tract) in the hemisphere on the non-preferred side and in the splenium of corpus callosum. In contrast, in the anterior internal capsule on the preferred side, the E-PT group had increased FA. Lower FA in the cerebral peduncle, but higher FA in the anterior internal capsule, was associated with increased movement segmentation across body-parts in a contralateral manner. The results suggest that impaired development of sensorimotor tracts in E-PT children could explain a sub-optimal spatiotemporal organization of upper-limb movements. Hum Brain Mapp 38:5051-5068, 2017. © 2017 Wiley Periodicals, Inc.
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Lactente Extremamente Prematuro/fisiologia , Atividade Motora/fisiologia , Transtornos dos Movimentos/diagnóstico por imagem , Transtornos dos Movimentos/fisiopatologia , Extremidade Superior/fisiologia , Substância Branca/diagnóstico por imagem , Fenômenos Biomecânicos , Criança , Imagem de Tensor de Difusão , Feminino , Lateralidade Funcional , Objetivos , Humanos , Imageamento Tridimensional , Masculino , Transtornos dos Movimentos/etiologia , Transtornos dos Movimentos/patologia , Substância Branca/patologiaRESUMO
This preliminary study explored if a collaborative and therapeutic approach (CTA) could reduce self-reported psychiatric symptoms (Beck Youth Inventories [BYI]) in children referred for neuropsychological assessment. Participants included 11 children (M(age )= 12.4 years) receiving CTA, 11 (M(age) = 12.6 years) receiving parent support, and 9 (M(age) = 12.3 years) remaining on a waiting list. Contrary to both comparison groups, the CTA group reported fewer psychiatric symptoms on most BYI subscales after intervention, and this decrease was sustained for the Anger and Anxiety subscales at 6-month follow-up. Findings support a potential effectiveness of CTA in the neuropsychological assessment of children in a child psychiatric setting.
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Adaptação Psicológica/fisiologia , Transtornos de Ansiedade/diagnóstico , Ansiedade/diagnóstico , Transtornos do Comportamento Infantil/diagnóstico , Depressão/diagnóstico , Adolescente , Criança , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Autoimagem , Inquéritos e Questionários , Fatores de TempoRESUMO
Few studies have investigated manual performance in infants when reaching and grasping for objects moving in directions other than across the fronto-parallel plane. The present preliminary study explored object-oriented behavioral strategies and side preference in 8- and 10-month-old infants during reaching and grasping for objects approaching in depth from three positions (midline, and 27° diagonally from the left and right). Effects of task constraint by using objects of three different types and two sizes were further examined for behavioral strategies and hand opening prior to grasping. Additionally, assessments of hand preference by a dedicated handedness test were performed. Regardless of object starting position, the 8-month-old infants predominantly displayed right-handed reaches for objects approaching in depth. In contrast, the older infants showed more varied strategies and performed more ipsilateral reaches in correspondence with the side of the approaching object. Conversely, 10-month-old infants were more successful than the younger infants in grasping the objects, independent of object starting position. The findings regarding infant hand use strategies when reaching and grasping for objects moving in depth are similar to those from earlier studies using objects moving along a horizontal path. Still, initiation times of reaching onset were generally long in the present study, indicating that the object motion paths seemingly affected how the infants perceived the intrinsic properties and spatial locations of the objects, possibly with an effect on motor planning. Findings are further discussed in relation to future investigations of infant reaching and grasping for objects approaching in depth.
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Given that the auditory system is rather well developed at the end of the third trimester of pregnancy, it is likely that couplings between acoustics and motor activity can be integrated as early as at the beginning of postnatal life. The aim of the present mini-review was to summarize and discuss studies on early auditory-motor integration, focusing particularly on upper-limb movements (one of the most crucial means to interact with the environment) in association with auditory stimuli, to develop further understanding of their significance with regard to early infant development. Many studies have investigated the relationship between various infant behaviors (e.g., sucking, visual fixation, head turning) and auditory stimuli, and established that human infants can be observed displaying couplings between action and environmental sensory stimulation already from just after birth, clearly indicating a propensity for intentional behavior. Surprisingly few studies, however, have investigated the associations between upper-limb movements and different auditory stimuli in newborns and young infants, infants born at risk for developmental disorders/delays in particular. Findings from studies of early auditory-motor interaction support that the developing integration of sensory and motor systems is a fundamental part of the process guiding the development of goal-directed action in infancy, of great importance for continued motor, perceptual, and cognitive development. At-risk infants (e.g., those born preterm) may display increasing central auditory processing disorders, negatively affecting early sensory-motor integration, and resulting in long-term consequences on gesturing, language development, and social communication. Consequently, there is a need for more studies on such implications.
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Despite the great need of interventions to maintain and improve motor functions in children with diplegic cerebral palsy (DCP), scientific evaluations of existing training methods are rare. This study aimed to explore individual effects of synchronized metronome training (SMT) on motor timing, spatio-temporal movement organization, and subjective experiences of changes in upper-limb functions in three children with DCP. All children participated in an individualized 4-week/12 session SMT training regime. Measurements before training (Pre), after training (Post1), and at 6 months post completed training (Post2) were made by the applied SMT training equipment, optoelectronic registrations of goal-directed upper-limb movements, and a questionnaire assessing subjective experiences of changes in upper-limb functions and usability. In general, the training regime was shown to have little effect on motor timing. However, some positive changes in spatio-temporal movement organization were found. Two children also reported substantial long-lasting positive changes in subjective experiences of hand/arm functionality in terms of increased movement control and reduced muscle tone. For these children, parallel kinematic findings also indicated smoother and faster movement trajectories that remained at Post2. Although highly individualized, the shown improvements in upper-limb kinematics and subjective experiences of improved functionality of the hands/arms for two of the cases warrant further explorations of SMT outcomes in children with DCP.
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This study explored upper-limb and head kinematics during unimanual goal-directed movements in children born preterm (PT) and full-term (FT) aged 4-8 years. Further, functional lateralization was investigated through side-specific kinematics and hand preference observations. Altogether, 141 children were included, divided into three sub-groups based on gestation week at birth (GW). Children born FT (38-41 GW) and moderately PT (33-35 GW) showed faster, smoother, and shorter movement trajectories than children born very PT (V-PT < 33 GW). Only children born FT expressed evident side differences that were characterized by smoother movements with the preferred side. Regarding hand preference, the children born V-PT showed increased rates of non-right-handedness compared with the other groups. Regardless of hand preference, the children born V-PT showed less well organized movements compared with the other groups. These findings suggest that spatio-temporal movement organization and side specialization at pre-/early school-age are affected by a PT birth, and more frequently so for children born before 33 GWs, indicating long-lasting influences on neuromotor development and specialization.