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This longitudinal study investigated the effect of experience with tactile stimulation on infants' ability to reach to targets on the body, an important adaptive skill. Infants were provided weekly tactile stimulation on eight body locations from 4 to 8 months of age (N = 11), comparing their ability to reach to the body to infants in a control group who did not receive stimulation (N = 10). Infants who received stimulation were more likely to successfully reach targets on the body than controls by 7 months of age. These findings indicate that tactile stimulation facilitates the development of reaching to the body by allowing infants to explore the sensorimotor correlations emerging from the stimulation. [ABSTRACT FROM AUTHOR]

The development of copying behaviours of a group of infants from 9 to 15 months of age is analysed. These behaviours are classified according to their type (mimetic or imitated) and function (instrumental, social or hybrid). The function of the behaviours is derived from observable indicators linked to dyadic interaction. Mimetic behaviours are maintained from 9 to 15 months, while imitative behaviours increase in frequency. The elicited copying situation promotes more behaviours with instrumental function, while other functions appear spontaneously. The concurrent and prospective relationships between copying behaviours – frequency, type and function- and receptive and expressive language are different through development. This study proposes an innovative definition of the functions of copying behaviours that is based on dynamic variables linked to interaction, in contrast to previous work that derives function from static variables such as context, object use and/or the body part performing the movement. [ABSTRACT FROM AUTHOR]

Several studies have previously investigated the effects of sticky mittens training on reaching and grasping development. However, recent critique casted doubts on the robustness of the motor effect of this training. The current study presents a pre‐registered report that aimed to generalize these effects to Swedish infants. Three‐month‐old infants N = 96, 51 females, mostly White middle class in Uppsala, received daily, parent‐led sticky mittens or observational training for 2 weeks or no training in 2019. Reaching and grasping abilities were assessed before and after training, using motion tracking and a 4‐step reaching task. Sticky mittens training did not facilitate successful reaching. These results indicate that beneficial motor effects of sticky mittens training did not generalize to this sample. [ABSTRACT FROM AUTHOR]

The objectives of this study were to verify the influence of a short-duration training session on proximal and distal adjustments at the onset of goal-directed reaching and to verify whether these adjustments change in specificity with the body position trained. Twenty-four infants aged 3-4 months were assessed in supine and reclined during pre and posttraining conditions. During the interval (4 min), 8 infants received reaching training in supine, 8 infants received reaching training in reclined, and 8 infants received no training. The frequencies of reaches, unimanual reaches and reaches with semiopen and oblique hand increased in the posttraining condition for all infants except control infants. Infants trained in the reclined position increased the frequencies of variables in the reclined position. Infants trained in the supine position increased the frequencies of variables in both positions. Few minutes of reaching training are effective to facilitate reaching behavior in infants at the onset of reaching. The effects are specific to the body position trained. As the training in supine requires higher torque to initiate reaching movements, it is more effective to facilitate reaches in both supine and reclined positions. [ABSTRACT FROM AUTHOR]

This study proposes a quantitative evaluation support system for infant motor development and uses the system to analyze hands-and-knees creeping and belly crawling. This system measures movements using two video cameras and extracts movement features via background and inter-frame subtractions of original images. Eight evaluation indices for each crawling cycle are calculated, enabling markerless movement analysis of infants. Cross-sectional analysis of 16 10-month-olds confirmed significant differences between hands-and-knees creeping and belly crawling in five of the eight indices, demonstrating the system capability to quantitatively differentiate between creeping and crawling. Longitudinal analysis of one infant (aged 7–10 months) also suggested that the proposed quantitative indices can follow changes in crawling characteristics and evaluate infants' motor development process. The results from the experiments suggest that the proposed system may enable diagnosis support in clinical practice. [ABSTRACT FROM AUTHOR]

Infants with Down syndrome (DS) are described as being less active and they also experience significant delays in motor development. It is hypothesized that early infant physical activity may be influential for the acquisition of independent walking. Physical activity was monitored longitudinally in 30 infants with DS starting at an average age of 10 months participating in a treadmill training intervention. Actiwatches were placed on infants' trunk and right ankle for a 24-hr period, every other month until walking onset. Data were analyzed to separate sedentary-to-light activity (low-act) and moderate-to-vigorous activity (high-act). Results showed that more leg high-act at an average age of 12 and 14 months is related to earlier onset of walking. It is recommended that early leg activity should be promoted in infants with DS. [ABSTRACT FROM AUTHOR]

This study explored the genetic and prenatal environmental influences on the development of reaching in twins. Detailed kinematic measures of arm movements and underlying muscle co-activation from two sets of monozygotic twins (MZ; one set was monochorionic; the other was dichorionic) and one set of dizygotic (DZ) were measured weekly from reach onset to 30 weeks, then bi-weekly to 1 year of age. Improvements in trajectories were not linear, but the MZ twins demonstrated higher correlations between kinematic variables compared to DZ twins and unrelated infants. Although all infants showed increase in muscle co-activation across the year, MZ twins showed no more correlations in muscle states than DZ twins or unrelated infants. The results suggest that reaches are not planned at the level of the muscles, and that anatomical, biomechanical, and energetic factors act as strong constraints on the inherent kinematic and muscle variability. [ABSTRACT FROM AUTHOR]

Maternal responsiveness (MR) is a predictor of the acquisition of motor skills by premature infants. This study aimed to verify associations between MR due to the number of offspring and motor development (MD) in preterm infants. Eighteen dyads participated in this study, divided into three groups: primiparous mothers with twin newborns (PMT), primiparous mothers (PM), and multiparous mothers (MM). Medical Records, the Social Interaction Scale (SIS), and a Motor Development Observation Protocol were used. In the Adaptive Fine Motor Development (AFMD), the PMT group presented more frequent "normal" outcomes (5; 83.3%), with a mean score of 13.2 points in the SIS (p < 0.0001). For those that evolved with "risk," in both AFMD and gross motor development (GMD), the MM group stood out (4; 66.7%), presenting a mean SIS score of 12.1 (p < 0.0001). The MR quality as a function of the offspring number is associated with AFMD and GMD of premature infants in the first year of life. [ABSTRACT FROM AUTHOR]

This article constitutes a desk study regarding animation of free time and its influence on the psychomotor development of infants aged over 3 months. The article discusses the concept of free time of infants. The motor and psychological development of children between the age of three months to one year is presented. Moreover, different ways of spending free time by the parent and child are shown. The aim of this article is to raise awareness of the role of supporting early child development through appropriate selection of games and other activities in line with the individual stage of development of an infant. The article has been prepared based on a literature review (including PubMed, Research Gate, EBSCO) as well as analysis of selected offers of commercial animation activities available in the city of Poznań, taking into account the individual stages of development and their impact on the comprehensive development of infants. Moreover, a list of activities recommended for children which are adequate to specific periods of their development was also prepared. [ABSTRACT FROM AUTHOR]

Studies of infant motor development in autism spectrum disorder (ASD) have increased in recent years. This article synthesized this literature through meta-analysis to assess (a) whether infant motor ability differs in ASD relative to neurotypical controls; and (b) whether motor ability and communication are related in infants with ASD. Study 1 aggregated data from 1,953 infants with ASD (ages 3.0-42.0 months), and Study 2 included 890 infants with ASD (age 6.0-42.9 months). Study 1 revealed that infant motor ability differed significantly in ASD compared with neurotypical infants-this difference was robust to variation in measurement and design. Furthermore, this group difference amplified as age increased. Study 2 indicated that within ASD, infant motor ability and communication are related. [ABSTRACT FROM AUTHOR]

Manual skills slowly develop throughout infancy and have been shown to create clear views of objects that provide better support for visually sustained attention, recognition, memory, and learning. These clear views may coincide with the development of manual skills, or that social scaffolding supports clear viewing experiences like those generated by toddlers during active object exploration. This study used a head-mounted eye tracker to record 5- to 24-month-olds' object views during repeated mother-infant play sessions (Ns = 18). Results show an early beginning of scaffolding in which parents generate views similar to those of older infants and toddlers, resulting in increased fixations to objects. The finding implicates parents as early scaffolders of object attention and learning. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the role of prenatal drug exposure on birth weight, birth length, head circumference. Apgar scores, length of gestation, and motor development (Psychomotor Development Index, PDI) scores. A meta-analytic review was conducted on 56 studies published between 1979 and June 25, 1993. There were 294 effect sizes computed using the means and standard deviations reported in each study. The composite effect sizes calculated for the growth and motor development variables were (a) -55. p < .01. birth weight; (b) -.74. p< .01. birth length; (c) - 79. p < 01. head circumference, (d) -.45. p< .01. 1-min Apgar score; (e)-.62. p< .01. 5-min Apgar score; (0 .36. p <.01. length of gestation; (g) -.07, p = .55. PDI score (3 months): (h) - 35. p <.01. PDI score (6 months); (i) -.74. p <.01, PDI score (12 months); (j) -.44. p <.01. PDI score (18 months); and (k) -.23. p < .01. PDI score (24 months). The results of this investigation demonstrated that the use/abuse of illicit substances, alcohol, or both by the mother docs significantly affect the physical and motor development of neonates/infants exposed in utero. [ABSTRACT FROM AUTHOR]

The purpose of this study was to describe the developmental stepping movements of 5 infants with Down syndrome who participated in a pediatric strength intervention. Pretest and posttest data were collected with the Hawaii Early Learning Profile Strands, Battelle Developmental Inventory, and specially designed gait analysis. An 8-week individualized Pediatric strength intervention was implemented according to theoretical principles of progressive interactive facilitation (Cowden, in press). Posttest data and the Snyder-McLean (1987) intervention developmental quotient suggested an increase in the subjects' rates of motor development during intervention as compared to their lifetime rates prior to intervention. One subject showed increased rate and distance, 2 subjects acquired independent upright locomotion, and 1 subject established independent sitting movements and creeping patterns. One subject was unable to complete the study. [ABSTRACT FROM AUTHOR]

Infants learn about objects by exploring them. Typically developing infants actively explore objects through visual, manual, and oral modalities. Attenuated exploratory behavior has been observed in various neurodevelopmental disorders, including Down syndrome (DS), presumably limiting learning options. However, a direct link between exploration and overall developmental functioning has not been characterized. This study used a Latent Profile Analysis framework to examine within-syndrome variability in exploratory behavior in infants with DS and the developmental correlates of different exploratory behavior profiles. Participants were 45 infants with DS (CA = 9.58 months; SD = 3.62) who completed an object exploration activity and the Bayley Scales of Infant Development-III (BSID-III; Bayley, 2006). Exploration behavior was coded for the percentage of time engaged in visual, manual, and oral exploration. Results indicated that a 2-profile solution provided the best model fit for exploratory behavior, yielding profiles that represented either an Active (57.78% of the sample) or a Passive Exploratory (42.22% of the sample) profile. The Active Exploratory profile was associated with significantly higher age equivalent scores on the BSID-III Cognitive, Communication, and Motor domains than the Passive Exploratory profile. Other factors, such as sex and biomedical risk factors, were not associated with exploratory profiles. These findings offer a more nuanced understanding of early within-syndrome heterogeneity in DS, and demonstrate that impoverished early exploratory behavior may serve as an important indicator of increased risk for more pronounced developmental delays in DS. [ABSTRACT FROM AUTHOR]

Motor difficulties may be an early Autism Spectrum Disorder (ASD) risk indicator and may predict subsequent expressive language skills. Further understanding of motor functioning in the first year of life in children with ASD is needed. We examined motor skills in 6-month-olds (n = 140) at high and low familial risk for ASD using the Peabody Developmental Motor Scales (Grasping, Visual-Motor Integration, and Stationary subscales). In Study 1, motor skill at 6 months predicted ASD status at 24-36 months; ASD was associated with poorer infant motor skills. In Study 2, motor skill at 6 months predicted expressive language at 30 and 36 months. Findings provide evidence that vulnerability in motor function early in development is present in ASD. Findings highlight the importance of developmental monitoring in high-risk infants and possible cascading effects of early disruption in motor development. [ABSTRACT FROM AUTHOR]

Objective: To examine whether a brief reaching training with sticky mittens was effective to improve reaching behavior in newly reaching preterm infants.Methods: In this randomized controlled trial, twenty four 5-month-old (±16-week-old corrected age) preterm infants were randomly allocated into experimental or control groups. Infants were assessed three times in a single session: pretraining (immediately before training), posttraining (immediately after training), and retention (4 min after the posttraining). During training, infants in the experimental group wore open fingers Velcro covered mittens. Training consisted of one 4-minute session of stimulated reaching using Velcro covered toys. Controls did not receive the training. During assessments, infants were placed in a baby chair and toys without Velcro were offered at their midline for 2 min. Number of total reaches, proximal adjustments and distal adjustments of reaching were primary outcomes. Grasping was a secondary outcome.Results: Groups were similar in the pretraining. In the posttraining, trained infants performed greater amount of total reaches and bimanual reaches than untrained infants. Greater amount of bimanual reaches in trained infants was maintained in the retention test. Distal adjustments and grasping outcome were not influenced by the training.Conclusions: A brief-term training with open fingers sticky mittens benefited reaching behavior and favored retention of increased bimanual reaches in newly reaching late preterm infants. However, it was not sufficient to influence hand openness and early grasping. [ABSTRACT FROM AUTHOR]

Infant posture and motor pattern development are normally analyzed by clinical assessment scales. Lately, this approach is combined with the use of sensor-supported systems, such as optical, inertial, and electromagnetic measurement systems, as well as novel assessment devices, such as CareToy. CareToy is a modular device for assessment and rehabilitation of preterm infants, comprising pressure mattresses, inertial and magnetic measurement units, and sensorized toys. Since such integrated sensor system combination is new to the field of sensor-supported infant behavior assessment and rehabilitation, dedicated methods for data analysis were developed and presented. These comprise trunk rotation, arm movement, forearm orientation, and head movement analysis, along with toy play and trunk posture stability evaluation. Methods were tested on case study data, evaluating suitability of developed algorithms for infant posture and activity analysis, regardless of behavioral responses. Obtained results demonstrate suitability of the proposed methods for successful use in studies of different motor pattern subfields. This represents an important step on the course towards objective, accurate, sensor-supported infant motor development assessment. Graphical abstract Posture and movement assessment of infants using analysis of sensory data, obtained with a dedicated sensorized gym with toys. [ABSTRACT FROM AUTHOR]

Background: Controversy exists regarding the optimal mode of delivery for fetuses with open neural tube defects.Objective: To compare neurological outcomes among infants with open neural tube defects who underwent vaginal compared with caesarean delivery.Search Strategy: Electronic databases MEDLINE, EMBASE, Scopus, and Clinicaltrials.gov were searched from inception to November 2017.Selection Criteria: Eligible studies included observational or randomised studies comparing vaginal and caesarean delivery in pregnancies with fetal open neural tube defects who did not undergo prenatal repair.Data Collection and Analysis: Two reviewers independently reviewed abstracts and full-text articles. Outcomes were compared between vaginal and caesarean delivery and prelabour caesarean versus exposure to labour. The primary outcome was motor-anatomic level difference. Secondary outcomes included shunt requirement, sac disruption, meningitis, and ambulation at 2 years. Meta-analysis was performed and mean difference or odds ratios with 95% CI were calculated.Main Results: Of 201 abstracts identified in the primary search, nine studies (672 women) met the eligibility criteria. Comparing vaginal and caesarean delivery, there was no significant difference in motor-anatomic level difference (mean difference -0.10, 95% CI -0.58 to 0.38; I2  = 57%). The vaginal delivery group was less likely to require a shunt or have sac disruption [odds ratio (OR) 0.37, 95% CI 0.14-0.95 and OR 0.46, 95% CI 0.23-0.90, respectively]. Comparisons by prelabour caesarean versus exposure to labour showed no significant difference in motor-anatomic level difference (OR 1.29, 95% CI 0.63-3.21) or ambulation at 2 years (OR 2.13, 95% CI 0.35-13.12).Conclusion: Caesarean delivery was not associated with improved neurological outcomes among fetuses with open neural tube defects.Tweetable Abstract: Available evidence does not support routine caesarean delivery for fetuses with open neural tube defects. [ABSTRACT FROM AUTHOR]

Research has identified early appearing differences in gross and fine motor abilities in infants at heightened risk (HR) for autism spectrum disorder (ASD) because they are the younger siblings of children with ASD, and it suggests that such differences may be especially apparent among those HR infants themselves eventually diagnosed with ASD. The present study examined overall and item-level performance on the gross (GM) and fine motor (FM) subscales of the Mullen Scales of Early Learning (MSEL) administered at 6 months to a large, geographically diverse sample of HR infants with varying developmental outcomes (ASD, elevated ADOS without ASD, low ADOS without ASD) and to infants with low ASD risk (low risk [LR]). We also explored whether motor abilities assessed at 6 months predicted ASD symptom severity at 36 months. FM (but not GM) performance distinguished all 3 HR groups from LR infants with the weakest performance observed in the HR-Elevated ADOS children, who exhibited multiple differences from both LR and other HR infants in both gross and fine motor skills. Finally, 6-month FM (but not GM) scores significant predicted 36-month ADOS severity scores in the HR group; but no evidence was found of specific early appearing motor signs associated with a later ASD diagnosis. Vulnerabilities in infants' fine and gross motor skills may have significant consequences for later development not only in the motor domain but in other domains. (PsycINFO Database Record (c) 2019 APA, all rights reserved). [ABSTRACT FROM AUTHOR]

According to the theory of conceptual metaphor, image-schemas and primary metaphors are preconceptual structures configured in human cognition, based on sensory-motor environmental activity. Focusing on the way both non-conceptual structures are embedded in early social interaction, we provide empirical evidence for the interactive and intersubjective ontogenesis of image-schemas and primary metaphors. We present the results of a multimodal image-schematic microanalysis of three interactive infant-directed performances (the composition of movement, touch, speech, and vocalization that adults produce for-and-with the infants). The microanalyses show that adults aesthetically highlight the image-schematic structures embedded in the multimodal composition of the performance, and that primary metaphors are also lived as embedded in these inter-enactive experiences. The findings allow corroborating that the psychological domains of cognition and affection are not in rivalry or conflict but rather intertwined in meaningful experiences. [ABSTRACT FROM AUTHOR]

Aim: Evidence is accumulating that motor and cognitive development are interrelated. This study investigates associations between motor development in infancy and cognitive function at 4 years of age.Method: This study is part of the Groningen prospective cohort study on the development of children born after assisted reproductive techniques such as in vitro fertilization. The study group consisted of 223 children (119 males, 104 females) born to subfertile couples (median gestational age 39.6wks, range 30-43wks). Motor behaviour was assessed with the Infant Motor Profile (IMP) at 4 months, 10 months, and 18 months. IQ was evaluated at 4 years with the Kaufman Assessment Battery for Children, Second Edition. Latent class growth modelling was used to analyse relations between IMP and IQ scores.Results: Infants with low total IMP scores had an IQ that was 8.9 points lower at 4 years than infants with typical IMP scores (95% confidence interval 3.6-14.1). Also, low scores in the domains of variation and performance were associated with a lower IQ at 4 years of age, by 6.1 points and 13.2 points respectively.Interpretation: Motor development in relatively low-risk infants is associated with cognition at 4 years of age. In particular, low motor variation and performance are associated with a lower IQ at 4 years of age.What This Paper Adds: Motor development in infancy is directly related to cognitive function at 4 years of age. This relationship is most pronounced for infant motor variation and performance. The size of the differences in IQ is clinically relevant. [ABSTRACT FROM AUTHOR]

Background: Synergistic recruitment of muscular activities is a generally accepted mechanism for motor function control, and motor dysfunction, such as cerebral palsy (CP), destroyed the synergistic electromyography activities of muscle group for limb movement. However, very little is known how motor dysfunction of CP affects the organization of the myoelectric frequency components due to the abnormal motor unit recruiting patterns. Objectives: Exploring whether the myoelectric activity can be represented with synergistic recruitment of surface electromyography (sEMG) frequency components; evaluating the effect of CP motor dysfunction on the synergistic recruitment of sEMG oscillations. Methods: Twelve CP infants and 17 typically developed (TD) infants are recruited for self-paced crawling on hands and knees. sEMG signals have been recorded from bilateral biceps brachii (BB) and triceps brachii (TB) muscles. Multi-scale oscillations are extracted via multivariate empirical mode decomposition (MEMD), and non-negative matrix factorization (NMF) method is employed to obtain synergistic pattern of these sEMG oscillations. The coefficient curve of sEMG oscillation synergies are adopted to quantify the time-varying recruitment of BB and TB myoelectric activity during infants crawling. Results: Three patterns of sEMG oscillation synergies with specific frequency ranges are extracted in BB and TB of CP or TD infants. The contribution of low-frequency oscillation synergy of BB in CP group is significantly less than that in TD group (p < 0.05) during forward swing phase for slow contraction; however, this low-frequency oscillation synergy keep higher level during the backward swing phase crawling. For the myoelectric activities of TB, there is not enough high-frequency oscillation recruitment of sEMG for the fast contraction in propulsive phase of CP infants crawling. Conclusion: Our results reveal that, the myoelectric activities of a muscle can be manifested as sEMG oscillation synergies, and motor dysfunction of CP degrade the synergistic recruitment of sEMG oscillations due to the impaired CNS regulation and destroyed MU/muscle fiber. Our preliminary work suggests that time-varying coefficient curve of sEMG oscillation synergies is a potential index to evaluate the abnormal recruitment of electromyography activities affected by CP disorders. [ABSTRACT FROM AUTHOR]

Iodine is an essential component for thyroid hormone synthesis. Epidemiological investigations have demonstrated that maternal mild iodine deficiency (ID)-induced hypothyroxinemia can affect intellectual and behavioral function in offspring. There is no definitive evidence demonstrating the effects of maternal iodine supplementation on neurobehavioral function in regional areas with mild ID. Thus, we aimed to clarify the effects of maternal mild ID and iodine supplementation on motor coordination in offspring and illuminate the underlying molecular mechanisms. Animal models of maternal mild ID and iodine supplementation were generated by providing Wistar rats an iodine-deficient diet and deionized water supplemented with potassium iodide during pregnancy and lactation. We found that mild ID-induced hypothyroxinemia led to a shorter latent time before falling down from the rotarod, a longer time to traverse the balance beam and poorer wire grip of the forelimbs, which imply motor coordination dysfunction. However, these impairments in the offspring were improved by iodine supplementation during pregnancy and lactation. We further observed that the ultrastructure and dendritic tree morphology of cerebellar Purkinje cells were altered in mild ID-induced hypothyroxinemia but that these changes could be reversed by iodine supplementation. Maternal mild ID and iodine supplementation also affected expression of the mGluR1 signaling pathway in offspring. Together, iodine supplementation during pregnancy and lactation can improve motor coordination in offspring by modulating the mGluR1 signaling pathway in mild ID-induced hypothyroxinemia rats. [ABSTRACT FROM AUTHOR]

Abstract: Face‐to‐face interaction between infants and their caregivers is a mainstay of developmental research. However, common laboratory paradigms for studying dyadic interaction oversimplify the act of looking at the partner's face by seating infants and caregivers face to face in stationary positions. In less constrained conditions when both partners are freely mobile, infants and caregivers must move their heads and bodies to look at each other. We hypothesized that face looking and mutual gaze for each member of the dyad would decrease with increased motor costs of looking. To test this hypothesis, 12‐month‐old crawling and walking infants and their parents wore head‐mounted eye trackers to record eye movements of each member of the dyad during locomotor free play in a large toy‐filled playroom. Findings revealed that increased motor costs decreased face looking and mutual gaze: Each partner looked less at the other's face when their own posture or the other's posture required more motor effort to gain visual access to the other's face. Caregivers mirrored infants' posture by spending more time down on the ground when infants were prone, perhaps to facilitate face looking. Infants looked more at toys than at their caregiver's face, but caregivers looked at their infant's face and at toys in equal amounts. Furthermore, infants looked less at toys and faces compared to studies that used stationary tasks, suggesting that the attentional demands differ in an unconstrained locomotor task. Taken together, findings indicate that ever‐changing motor constraints affect real‐life social looking. [ABSTRACT FROM AUTHOR]

Purpose: Infant vocal durations have been studied from a variety of perspectives, including medical, social, and linguistic. The resultant developmental profile across the first 6 months of life, however, is still far from clear. The purpose of this study was to evaluate the durational properties of infant vocalizations from the unique perspective of voice quality. By considering an infant's modal and nonmodal voice qualities, the developmental range of vocalizations produced by infants during the early months of life was captured. Method: Four Australian English--speaking infants were recorded for approximately 1 hr per week during the first 6 months of life. A total of 6,309 vocalizations were perceptually identified and labeled according to voice quality. The duration of each vocalization was subsequently measured. Results: A nonlinear curve was evident for the duration of all vocalizations combined. Duration increased significantly between Months 3 and 5. Modal voice was the only voice quality that displayed a linear increase in duration across the study. All other voice qualities displayed polynomial trends. Conclusions: Based on the current results, the inconsistent pattern of vocal duration development found previously can be reconciled when voice quality properties of vocalizations are taken into account. A nonlinear curve is evident when a broad corpus of infant vocalizations is used, whereas a narrow corpus containing predominantly modal vocalizations displays a linear trend. The results demonstrate the necessity of including nonmodal voice qualities in infant duration experiments so as to not overstate the linear nature of duration increases. [ABSTRACT FROM AUTHOR]

Abstract: Pointing is one of the communicative actions that infants acquire during their first year of life. Based on a hypothesis that early pointing is triggered by emergent reaching behavior toward objects placed at out‐of‐reach distances, we proposed a neural network model that acquires reaching without explicit representation of ‘targets’. The proposed model controls a two‐joint arm in a horizontal plane, and it learns a loop of internal forward and inverse transformations; the former predicts the visual feedback of hand position and the latter generates motor commands from the visual input through random generation of the motor commands. In the proposed model, the motor output and visual input were represented by broadly tuned neural units. Even though explicit ‘targets’ were not presented during learning, the simulation successfully generated reaching toward visually presented objects at within‐reach and out‐of‐reach distances. [ABSTRACT FROM AUTHOR]

Objective To evaluate the validity of the Test of Infant Motor Performance (TIMP) and general movements (GMs) assessment for predicting Alberta Infant Motor Scale (AIMS) score at 12 months in preterm infants. Methods A total of 44 preterm infants who underwent the GMs and TIMP at 1 month and 3 months of corrected age (CA) and whose motor performance was evaluated using AIMS at 12 months CA were included. GMs were judged as abnormal on basis of poor repertoire or cramped-synchronized movements at 1 month CA and abnormal or absent fidgety movement at 3 months CA. TIMP and AIMS scores were categorized as normal (average and low average and >5th percentile, respectively) or abnormal (below average and far below average or <5th percentile, respectively). Correlations between GMs and TIMP scores at 1 month and 3 months CA and the AIMS classification at 12 months CA were examined. Results The TIMP score at 3 months CA and GMs at 1 month and 3 months CA were significantly correlated with the motor performance at 12 months CA. However, the TIMP score at 1 month CA did not correlate with the AIMS classification at 12 months CA. For infants with normal GMs at 3 months CA, the TIMP score at 3 months CA correlated significantly with the AIMS classification at 12 months CA. Conclusion Our findings suggest that neuromotor assessment using GMs and TIMP could be useful to identify preterm infants who are likely to benefit from intervention. [ABSTRACT FROM AUTHOR]

It was the aim of this study to examine the motor and cognitive development of infants with congenital idiopathic clubfoot, compared with typically developing infants. We repeatedly tested the gross motor, fine motor, and cognitive abilities of 12 infants with clubfoot and 12 typically developing infants at the ages of 4, 6, 9, and 12 months with the Bayley-III Scales. All infants with clubfoot were treated with the Ponseti method, which led to a restriction of normal movements of the lower extremities in the first months of life. They showed a great delay in gross motor development but not in fine motor or cognitive development. However, in the clubfoot group, we found some slight deficits in specific cognitive tasks, including problem solving and spatial memory. In addition, our results revealed significant correlations between gross and fine motor performance and cognitive performance in the control group but only between fine motor and cognitive performance in infants with clubfoot, indicating that both, fine and gross motor skills, are related to cognitive processes and can mutually replace each other to a certain degree. Further research is needed to gain a deeper understanding of clubfoot infants' development and to clarify the need for mobility training. [ABSTRACT FROM AUTHOR]

This article critically reviews kinematic measures of prospective motor control. Prospective motor control, the ability to anticipatorily adjust movements with respect to task demands and action goals, is an important process involved in action planning. In manual object manipulation tasks, prospective motor control has been studied in various ways, mainly using motion tracking. For this matter, it is crucial to pinpoint the early part of the movement that purely reflects prospective (feedforward) processes, but not feedback influences from the unfolding movement. One way of defining this period is to rely on a fixed time criterion; another is to base it flexibly on the inherent structure of each movement itself. Velocity--as one key characteristic of human movement--offers such a possibility and describes the structure of movements in a meaningful way. Here, I argue for the latter way of investigating prospective motor control by applying the measure of peak velocity of the first movement unit. I further discuss movement units and their significance in motor development of infants and contrast the introduced measure with other measures related to peak velocity and duration. [ABSTRACT FROM AUTHOR]

Previous research demonstrates that infants adapt and plan their actions based on object weight, but fewer studies have investigated how infants' understanding of object weight shapes their understanding of physical events. The present study investigates 10-month-old infants' understanding of the effect of object weight in support events--specifically, that object weight impacts whether a supporting surface will become compressed or not--and its relation to motor development. In Experiment 1, using an action task, we found that infants infer an object's weight based on whether it compresses a supporting surface, as demonstrated by reaches to the light object following the support event. In Experiment 2, using a violation-of-expectation paradigm, we found that infants generate predictions for the outcome of support events involving heavy and light objects (i.e., they expect heavy, but not light, objects to compress a supporting surface), as demonstrated by longer looking to inconsistent events relative to consistent. Neither experiment found relations with infants' motor development. These findings demonstrate that infants invoke a concept of object weight when interpreting and predicting the outcomes of physical events and that the ability to reason about object weight as a causal factor in physical events is relatively sophisticated in infancy. [ABSTRACT FROM AUTHOR]

From birth, infants encounter an environment full of objects and learn rapidly about their spatial characteristics. According to Newcombe, Uttal, and Sauter (2013), spatial development includes (1) the development of intraobject representations with the ability to transform them by mental rotation, and (2) the development of interobject representations with the ability to find and predict certain object locations. Infants' remarkable improvements of these two strands of spatial object processing raise the major question of which factors may drive them. In this article, we discuss the extent to which infants' development of intra- and interobject representations is related to their emerging motor skills. In particular, we provide a review on how far infants' development of mental object rotation ability and their ability to localize objects are related to their manual object exploration and locomotion skills. We document a bulk of evidence suggesting such a link between infants' motor development and their spatial object processing and also discuss and critically reconsider the implications of these studies. [ABSTRACT FROM AUTHOR]

Hands and knees crawling is an important motor developmental milestone but the current clinical measures of motor function during crawling stage are relatively subjective. Objective metrics using kinematics and electromyography (EMG) in infant crawling may provide more stable and accurate measures of such developmental milestone, demonstrating changes in locomotion during age span. The purpose of this paper was to determine whether joint kinematics and the underlying co-activation between flexor and extensor in infant crawling are different for arms and legs across the infant age span. Surface EMG of two pairs of flexors and extensors from arms and legs and the corresponding joint kinematic data were collected in twenty health infants (11 males and 9 females, range 8–15 months), while they were crawling on hands and knees. Co-activation index of averaged EMG was used to quantify the simultaneous contractions between flexor and extensor muscles. Coefficient of variation of joint’s maximum vertical acceleration from multiple cycles was used to quantify the repeatability of kinematics during crawling. Our results indicated that the arm exhibited significantly higher co-activation and higher repeatability of joint movement than the leg, suggesting earlier development of arm compared to leg. Moreover, elder age groups, who had stronger walking ability developed, showed increased co-activation of the leg and significant increase in repeatability of the knee movement. These results were consistent with the rapid reinforcement of the leg during motor development from quadrupeds to bipedal walking. Furthermore, the EMG and kinematic parameters were significantly correlated with clinical variables. These results suggest that the EMG and kinematic analysis of infant crawling are useful in building effective assessment of infant’s motor function before independent walking. [ABSTRACT FROM PUBLISHER]

Aim: To examine the diagnostic ability of early magnetic resonance imaging (MRI; <36wks postmenstrual age) to detect later adverse motor outcomes or cerebral palsy (CP) in infants born preterm.Method: Studies of infants born preterm with MRI earlier than 36 weeks postmenstrual age and quantitative motor data or a diagnosis of CP at or beyond 1 year corrected age were identified. Study details were extracted and meta-analyses performed where possible. Quality of included studies was evaluated with the QUADAS-2 (a revised tool for the quality assessment of diagnostic accuracy studies).Results: Thirty-one articles met the inclusion criteria, five of which reported diagnostic accuracy and five reported data sufficient for calculation of diagnostic accuracy. Early structural MRI global scores detected a later diagnosis of CP with a pooled sensitivity of 100% (95% confidence interval [CI] 86-100) and a specificity of 93% (95% CI 59-100). Global structural MRI scores determined adverse motor outcomes with a pooled sensitivity of 89% (95% CI 44-100) and a specificity of 98% (95% CI 90-100). White matter scores determined adverse motor outcomes with a pooled sensitivity of 33% (95% CI 20-48) and a specificity of 83% (95% CI 78-88).Interpretation: Early structural MRI has reasonable sensitivity and specificity to determine adverse motor outcomes and CP in infants born preterm. Greater reporting of diagnostic accuracy in studies examining relationships with motor outcomes and CP is required to facilitate clinical utility of early MRI.What This Paper Adds: Early magnetic resonance imaging (MRI) has reasonable sensitivity and specificity to determine later adverse motor outcomes and cerebral palsy (CP). Detection of infants who progressed to CP was stronger than motor outcomes. Global MRI scores determined adverse motor outcomes more accurately than white matter scores. Few studies report diagnostic accuracy of early MRI findings. Diagnostic accuracy is required to draw clinically meaningful conclusions from early MRI studies. [ABSTRACT FROM AUTHOR]

Breastfeeding (BF) confers numerous benefits on the developing infant in both the short and the long term including psychological development, but there are multiple other factors that must be taken into account when these relationships are studied. To analyse how breastfeeding during the first 4 months of life affects infant mental and psychomotor development (MPD) at 6 and 12 months in a group of healthy infants from a Mediterranean Spanish city considering many important potential confounds. This is a longitudinal study conducted on infants from birth until the age of 12 months. A total of 154 healthy infants were evaluated by Paediatric Unit of Sant Joan University Hospital in Reus, Spain. Type of feeding, clinical history, anthropometry, iron status and mental and psychomotor development were assessed and analysed. At 4 months, 24% of infants received BF and 26% received mixed feeding (MF). Multiple Linear Regression models were applied adjusting for potential prenatal, perinatal and postnatal confounds showing that infants who received BF for at least four months presented higher psychomotor development index (PDI) at 6 and at 12 months of age. Also, gestational age and BMI at 6m were associated positively with PDI at 6 m, and haemoglobin levels at 12m and birth height were associated with PDI and MDI at 12m (respectively). In conclusion, after the adjustment of important potential confounds, BF during at least four months and adequate infant iron status are related to better psychomotor development during the first year. No associations were found between BF and mental development. [ABSTRACT FROM AUTHOR]

This study identified the level of trunk control of healthy term infants aged from six to nine months. This cross-sectional study included fifty-five infants aged from six to nine months. The levels of trunk control was investigated by using the Segmental Assessment Trunk Control (SATCo). The infants remained seated on a wooden bench and a neutral pelvic position was maintained. The SATCo score was considered as dependent variable. The results showed that infants aged six and seven months presented levels of trunk control in the thoracic region while infants aged from eight to nine months presented full trunk control. These results demonstrate that younger infants present less levels of trunk control while older infants present full trunk control, confirming that trunk control development takes place in a segmental way and in a cephalocaudal direction. These results also might be used as a reference to distinguish infants that show a delay in trunk control from those who have suitable motor development and, thus intervene at an early stage to minimize later delays in these infantś global motor development. [ABSTRACT FROM AUTHOR]

Existing research in infants has correlated electroencephalography (EEG) measures of power and coherence to cognitive development and to locomotor experience, but only in infants older than 5 months of age. Our goal was to explore the relationship between EEG measures of power and coherence and motor skill development in younger infants who are developing reaching skill. Twenty-one infants with typical development between 38 and 203 days of age participated. Longitudinal EEG recording sessions were recorded in monthly increments, with 3–5 sessions acquired for 19 participants and 1 session for 2 participants, resulting in 71 sessions in total. EEG variables of interest were relative power in the 6–9 Hz range and coherence between selected electrode pairs. We describe the development of the peak in relative power in the 6–9 Hz frequency band of EEG; it is not present around 1 month of age and starts to appear across the following months. Coherence generally increased in the bilateral frontal-parietal networks, while the interhemispheric connectivity in motor cortices generally decreased. The results of this relatively small pilot study provide a foundational description of neural function changes observed as motor skills are changing across the first half year of life. This is a first step in understanding experience-dependent plasticity of the infant brain and has the potential to aid in the early detection of atypical brain development. [ABSTRACT FROM AUTHOR]

This study examined the effect of meals varying in amount, size, and hardness of food pieces on the development of the chewing capabilities of 8-month-old infants. The study also examined changes in shivering, gagging, coughing, choking, and their ability to eat from a spoon. In an in-home setting two groups were given commercially available infant meals and fruits, purees with either less, smaller and softer or more, larger and harder pieces. Both groups were given these foods for 4 weeks and were monitored several times during this period. After the 4-week exposure period infants in both groups were given the same five test foods. Structured questionnaires with questions on eating behavior and the child's development were conducted 6 times in the 4 to 12-month period and video analyses of feedings were conducted 4 times between 8 and 9 months. After the 4-week exposure period, the group that had been exposed to the foods with more, larger and harder pieces showed a significantly higher rating for chewing a piece of carrot and potato for the first time, but not for a piece of banana nor for mashed foods. Shivering, gagging, coughing, choking, and ability to eat from a spoon were not different between the two groups. These results contribute to the insight that exposure to texture is important for young children to learn how to handle texture. Practical applications (a) The study shows the feasibility of testing the effects of texture interventions on chewing capability and oral responses such as gagging, coughing, and choking in infants. (b) The study contributes to the insight that exposure to food texture to learn how to handle texture is important for infants and showed that exposing children to a higher amount of larger pieces improves their chewing capability for a piece of carrot and potato, at least immediately after the intervention. [ABSTRACT FROM AUTHOR]