Development of eye-hand coordination in typically developing children and adolescents assessed using a reach-to-grasp sequencing task

Eye-hand coordination is required to accurately perform daily activities that involve reaching, grasping and manipulating objects. Studies using aiming, grasping or sequencing tasks have shown a stereotypical temporal coupling pattern where the eyes are directed to the object in advance of the hand movement, which may facilitate the planning and execution required for reaching. While the temporal coordination between the ocular and manual systems has been extensively investigated in adults, relatively little is known about the typical development of eye-hand coordination. Therefore, the current study addressed an important knowledge gap by characterizing the profile of eye-hand coupling in typically developing school-age children (n = 57) and in a cohort of adults (n = 30). Eye and hand movements were recorded concurrently during the performance of a bead threading task which consists of four distinct movements: reach to bead, grasp, reach to needle, and thread. Results showed a moderate to high correlation between eye and hand latencies in children and adults, supporting that both movements were planned in parallel. Eye and reach latencies, latency differences, and dwell time during grasping and threading, showed significant age-related differences, suggesting eye-hand coupling becomes more efficient in adolescence. Furthermore, visual acuity, stereoacuity and accommodative facility were also found to be associated with the efficiency of eye-hand coordination in children. Results from this study can serve as reference values when examining eye and hand movement during the performance of fine motor skills in children with neurodevelopmental disorders.     

The Effects of Screen Refresh Rate on Editing Operations Using a Computer Mouse Pointing Device

Two experiments are described in which subjects attempted to locate a specified target word in a short text using a cursor controlled by a computer mouse pointing device. The task was performed at screen refresh rates of 50 Hz, 75 Hz, and 100 Hz. In Experiment 1, both the timing and accuracy of the cursor movement was influenced by screen pulsation. During the early phase of the movement, performance was worse at 100 Hz, whereas in the later, visually guided phase, performance was worse at 50 Hz. In Experiment 2, eye movements were recorded as the task was performed. The results show that the cursor movement is typically preceded by an eye movement and that subjects do not directly inspect the cursor in the early stages of its movement. In the later phase of the movement the cursor is tracked for considerable periods of time. The data suggest that adverse effects of screen pulsation on the control of cursor movement are inherited from penalties incurred during the process of target computation but may also be influenced by concurrent eye movements.     

Children show limited movement repertoire when learning a novel motor skill

Examining age differences in motor learning using real‐world tasks is often problematic due to task novelty and biomechanical confounds. Here, we investigated how children and adults acquire a novel motor skill in a virtual environment. Participants of three different age groups (9‐year‐olds, 12‐year‐olds, and adults) learned to use their upper body movements to control a cursor on a computer screen. Results showed that 9‐year‐old and 12‐year‐old children showed poorer ability to control the cursor at the end of practice. Critically, when we investigated the movement coordination, we found that the lower task performance of children was associated with limited exploration of their movement repertoire. These results reveal the critical role of motor exploration in understanding developmental differences in motor learning.     

Practice Effects in Bimanual Force Control: Does Age Matter?

ABSTRACT

The authors examined age-related differences in fine motor control during a bimanual coordination task. The task required the modulation of fingertip forces in the precision grip according to a visually presented sinusoidal antiphase pattern (force range 2–12 N; frequency 0.2 Hz). Thirty-four right-handed participants of three age groups (young, early middle-aged, and late middle-aged) practiced 30 trials of the task. Accuracy and variability of relative timing and relative forces at minima and maxima of the sine wave were analyzed for hand–hand and hand–stimulus couplings and compared between age groups. Analysis showed for relative timing and force weaker hand–hand than hand–stimulus coupling as well as lower accuracy and higher variability for minima as compared to maxima. Further, we analyzed practice effects by comparing the first and last trials and characterized the course of practice by detecting the transition of a steeper to a shallower acquisition slope for the different age groups. Late middle-aged participants demonstrated poorer performance than both other groups for all parameters. All groups improved performance to a similar amount. However, an age-related difference in acquisition strategy is visible. Late middle-aged participants seemed to have focused on improvement of force amplitude, whereas young and early middle-aged focused on timing.     

Childhood Attention-Deficit/Hyperactivity Disorder Predicts Intimate Partner Victimization in Young Women

Attention-deficit/hyperactivity disorder (ADHD) is associated with interpersonal dysfunction during childhood and adolescence, yet little is known about the romantic relationships of young women with childhood ADHD. In the present study, we draw from a longitudinal sample of girls followed prospectively into young adulthood, comparing those with (n?=?114) and without (n?=?79; comparisons) childhood ADHD in terms of their risk for physical victimization by an intimate partner (physical IPV; e.g., slapping, punching) by 17–24 years of age. We examined ADHD both diagnostically and dimensionally, at the same time establishing reliable indicators of young adult physical IPV. Externalizing and internalizing problems, and academic achievement during adolescence, were tested as potential mediators. Overall, participants with a childhood diagnosis of ADHD experienced more physical IPV than did comparisons (30.7 % vs. 6.3 %). In parallel, IPV was associated with higher levels of childhood ADHD symptomatology (d?=?0.73). Young women with persistent ADHD stood the highest risk of experiencing IPV (37.3 %), followed by those with transient ADHD (19.0 %) and those never-diagnosed (5.9 %). Academic achievement measured during adolescence was a significant partial mediator of the childhood ADHD symptomatology-young adult IPV relationship, even with control of sociodemographic, psychiatric, and cognitive factors, including childhood reading and math disorders. Findings indicate that in young women, childhood ADHD is a specific and important predictor of physically violent victimization in their intimate relationships. This vulnerable population requires IPV prevention and intervention, with academic empowerment as a key target.     

Pupil Diameter May Reflect Motor Control and Learning

Non–luminance-mediated changes in pupil diameter have been used since the first studies by Darwin in 1872 as indicators of clinical, cognitive, and arousal states. However, the relation between processes involved in motor control and changes in pupil diameter remains largely unknown. Twenty participants attempted to compensate random walks of a cursor with a computer mouse to restrain its trajectory within a target circle while the authors recorded their pupil diameters. Two conditions allowed the authors to experimentally manipulate the motor and cognitive components of the task. First, the step size of the cursor's random walk was either large or small leading to 2 task difficulties (difficult or easy). Second, they instructed participants to imagine controlling the cursor by moving the mouse, but without actually moving it (task modality: imagined movement or real movement condition). Task difficulty and modality allowed the authors to show that pupil diameters reflect processes involved in motor control and in the processing of feedback, respectively. Furthermore, the authors also demonstrate that motor learning can be quantified by pupil size. This noninvasive approach provides a promising method for investigating not only motor control, but also motor imagery, a research field of growing importance in sports and rehabilitation.     

Second-order motor planning difficulties in children with developmental coordination disorder

The second-order motor planning ability of children with developmental coordination disorder (DCD) has often been studied using tasks that require judgements of end-state comfort (ESC). In these studies, children may have chosen to prioritize other aspects of performance (e.g., a comfortable start-posture) over ESC while still being able to complete the goal of the task. This is a limitation that is inherent to previously used ESC paradigms. To avoid this in the present study, 52 children with and without DCD (aged 5–12 years) completed a task that requires second-order motor planning for its successful completion. In the hexagonal knob task, children were instructed to grasp and rotate a hexagonal knob. The rotation angle varied in size: 60°, 120°, 180°, and 240° rotations. Both the 180° and 240° rotation conditions required an uncomfortable starting posture for successful task completion. Results showed that children with DCD were less likely to adjust their initial grip in anticipation of the required rotation angle, resulting in more task failures compared with typically developing (TD) children. Based on this finding we conclude that children with DCD experience genuine second-order motor planning difficulties. Analysis of temporal outcomes, showed that initial reaction time increased with rotation angle, but this was less pronounced for children with DCD than for TD children. There were no between group differences in timing of subsequent events. These results suggest that the difficulties of children with DCD are related to the initial planning process, that is, before the start of the movement.     

From Parent to Child to Parent…: Paths In and Out of Problem Behavior

This study used data from the NICHD Study of Early Child Care and Youth Development to examine relations between parenting, self-control and externalizing behavior from early childhood to mid-adolescence (N?=?956; 49.9 % male). Results indicated that maternal sensitivity, parental harshness and productive activity are related to externalizing problems but that patterns of relations change from early childhood to middle childhood to adolescence, with evidence suggesting that externalizing behavior influences parenting more than the reverse from middle childhood onward. Self-control measured during early adolescence partially mediated relations between maternal sensitivity and adolescent-reported externalizing behavior. Parental monitoring during adolescence was also related to externalizing behavior at age 15. Monitoring partially mediated the relation between externalizing behavior in early adolescence and externalizing at age 15.     

Parenting and Anxiety: Bi-directional Relations in Young Children

Developmental psychopathologists have long posited a reciprocal relation between parenting behaviors and the development of child anxiety symptoms. Yet, little empirical research has utilized a longitudinal design that would allow exploration of this bi-directional influence. The present study examined the reciprocal relations between parental respect for autonomy, parental hostility, and parental support, and the development of childhood anxiety during a critical developmental period-the transition from preschool to kindergarten and then first grade. Study participants included a community sample of 391 male and 405 female socioeconomically, racially and ethnically diverse 4 to 6–7 year olds. 54 % of the sample was White, non-Hispanic, 16.8 % was African American, 20.4 % was Hispanic, 2.4 % were Asian and 4.4 % self-identified as Other or mixed race. Parent report and observational methodology were used. Parenting and anxiety were found to interact reciprocally over time. Higher levels of age 4 anxiety led to reduced respect for child autonomy at age 5. At age 4 higher levels of parental hostility led to small increases in age 5 anxiety, and increased age 5 anxiety led to increased levels of age 6 parent hostility. Parental support at age 5 resulted in decreased anxiety symptoms at age 6–7 while higher age 5 anxiety levels were associated with reductions in age 6–7 parental support. No relations were found between these variables at the younger ages. Although the magnitude of these findings was small, they suggest that early treatment for childhood anxiety should include both parent intervention and direct treatment of the child’s anxiety symptoms.     

Exposure to the Chinese famine in early life and depression in adulthood

We aimed to investigate whether exposure to the Chinese famine (1959–1961) in early life was associated with depression in adulthood. We included 17,505 participants from the China health and retirement longitudinal study (CHARLS). Participants were classified into indirect and direct exposure groups. And the directly exposure groups including prenatal, childhood, adolescence/adult exposure groups. Depression was diagnosed by Center for Epidemiological Studies Depression Scale-10 (CES-D) score. Multivariate logistic regression model was used to calculate the odd ratios (ORs) and 95% confidence intervals (CIs) of depression. In women, prenatal, childhood, adolescence/adult exposure groups had higher depression risk than indirect exposure group (OR = 1.46, 1.40, and 1.67, respectively). However, there was no significant association between famine exposure and depression among men. Exposure to famine during prenatal (OR: 1.48; 95% CI: 1.07–2.06), childhood (OR: 1.47; 95% CI: 1.13–1.91), and adolescence/adult (OR: 1.63; 95% CI: 1.24–2.15) period were associated with depression among subjects living in rural, but not those living in urban. Exposure to the Chinese famine in early life had sex and area-specific associations with depression.     

Colour correspondence effects between controlled objects and targets

It is increasingly popular to use movement trajectories as a measure of mental processes related to task performance. Often this is accomplished by moving a cursor to a target on a computer screen. However, the relation between features of the cursor and the targets is rarely, if at all, considered. In five experiments, we examined whether moving a cursor to a target was affected by the relation between their colours, even when this relation was task irrelevant. In Experiments 1–3, a mouse-controlled cursor was moved to one of two coloured targets. Results showed colour correspondence effects in latency to initiate a response, duration of movement times, and movement trajectories when the relationship between cursor and target colours was task relevant (Experiment 1) and when only the cursor colour was task relevant (Experiment 2), but not when only the target was task relevant (Experiment 3). Follow-up experiments using single targets showed that colour correspondence effects occurred as long as attention was dedicated to the colour of the cursor, even when neither the cursor nor the target colour was relevant to selecting the correct movement (Experiments 4 and 5). Furthermore, when the relation between cursor and target colours is task irrelevant, colour correspondence effects for response initiation times are uncorrelated with those for movement times and movement trajectories. We interpret the observed correspondence effect in terms of response coding, although attention cueing may also play a role, and suggest that greater consideration of cursor features is needed when examining movement trajectories in choice reaction tasks.     

Development of sensorimotor synchronization abilities: Motor and cognitive components

The aim of the present study was to examine both the development of sensorimotor synchronization in children in the age range from 5 to 8 years and the involvement of motor and cognitive capacities. Children performed a spontaneous motor tempo task and a synchronization–continuation task using an external auditory stimulus presented at three different inter-stimulus intervals: 500, 700, and 900 ms. Their motor and cognitive abilities (short-term memory, working memory, and attention) were also assessed with various neuropsychological tests. The results showed some developmental changes in synchronization capacities, with the regularity of tapping and the ability to slow down the tapping rate improving with age. The age-related differences in tapping were nevertheless greater in the continuation phase than in the synchronization phase. In addition, the development of motor capacities explained the age-related changes in performance for the synchronization phase and the continuation phase, although working memory capacities were also involved in the interindividual differences in performance in the continuation phase. The continuation phase is thus more cognitively demanding than the synchronization phase. Consequently, the improvement in sensorimotor synchronization during childhood is related to motor development in the case of synchronization but also to cognitive development with regard to the reproduction and maintenance of the rhythm in memory.     

Individual differences in motor development during early childhood: An MEG study

In a previous study, we reported the first measurements of pre‐movement and sensorimotor cortex activity in preschool age children (ages 3–5 years) using a customized pediatric magnetoencephalographic system. Movement‐related activity in the sensorimotor cortex differed from that typically observed in adults, suggesting that maturation of cortical motor networks was still incomplete by late preschool age. Here we compare these earlier results to a group of school age children (ages 6–8 years) including seven children from the original study measured again two years later, and a group of adults (mean age 31.1 years) performing the same task. Differences in movement‐related brain activity were observed both longitudinally within children in which repeated measurements were made, and cross‐sectionally between preschool age children, school age children, and adults. Movement‐related mu (8–12 Hz) and beta (15–30 Hz) oscillations demonstrated linear increases in amplitude and mean frequency with age. In contrast, movement‐evoked gamma synchronization demonstrated a step‐like transition from low (30–50 Hz) to high (70–90 Hz) narrow‐band oscillations, and this occurred at different ages in different children. Notably, pre‐movement activity (‘readiness fields’) observed in adults was absent in even the oldest children. These are the first direct observations of brain activity accompanying motor responses throughout early childhood, confirming that maturation of this activity is still incomplete by mid‐childhood. In addition, individual children demonstrated markedly different developmental trajectories in movement‐related brain activity, suggesting that individual differences need to be taken into account when studying motor development across age groups.     

眼动交互中边框和视标对作业绩效的影响研究

研究人计算机界面设计中的眼动交互反馈方式,为优化基于视线追踪技术的人计算机界面设计提供工效学依据。12名被试在交互对象有无边框提示和当前注视位置有无视标反馈的四种组合条件下,通过眼动交互完成目标选择任务,由计算机自动记录作业时间、选择错误和超时数目。结果发现,有无当前注视位置的视标反馈对作业时间有显著影响,有视标反馈可加速目标字母的搜索与定位过程和目标激活过程,由视标反馈所产生的作业时间下降,主要由目标定位时间的缩短所致;边框提示对用户的作业绩效无显著影响。根据上述结果可得以下结论:对当前注视位置提供视标反馈是一种有效的反馈方式,基于视线追踪的人机交互系统应为用户提供这种反馈信息。     

About the role of bottom-up and top-down processes on perception–action interaction in sensorimotor transformations

Theories of common-coding propose that feature codes of perceived and to-be-produced events are likely to interact with each other when they overlap. We investigated the impact of bottom-up and top-down processes on cross talk in a motor replication task. Participants moved a pen on a covered digitizer tablet while a gain varied the relation between hand and cursor amplitude. Then, participants replicated the hand amplitude (intra-modal) or the cursor amplitude (intermodal) without visual feedback. We replicated that, when the not-to-be-replicated amplitude was longer (shorter) than the to-be-replicated amplitude, replications significantly overshot (undershot) (= after-effects). Importantly, after-effects were remarkably smaller in the experimental groups which wore gloves (thin and thick rubber) or goggles (clear and tinted lenses) than in a control group. Our results provide evidence that top-down attention modulated perception–action interaction.     

Adolescent-specific patterns of behavior and neural activity during social reinforcement learning

Humans are sophisticated social beings. Social cues from others are exceptionally salient, particularly during adolescence. Understanding how adolescents interpret and learn from variable social signals can provide insight into the observed shift in social sensitivity during this period. The present study tested 120 participants between the ages of 8 and 25 years on a social reinforcement learning task where the probability of receiving positive social feedback was parametrically manipulated. Seventy-eight of these participants completed the task during fMRI scanning. Modeling trial-by-trial learning, children and adults showed higher positive learning rates than did adolescents, suggesting that adolescents demonstrated less differentiation in their reaction times for peers who provided more positive feedback. Forming expectations about receiving positive social reinforcement correlated with neural activity within the medial prefrontal cortex and ventral striatum across age. Adolescents, unlike children and adults, showed greater insular activity during positive prediction error learning and increased activity in the supplementary motor cortex and the putamen when receiving positive social feedback regardless of the expected outcome, suggesting that peer approval may motivate adolescents toward action. While different amounts of positive social reinforcement enhanced learning in children and adults, all positive social reinforcement equally motivated adolescents. Together, these findings indicate that sensitivity to peer approval during adolescence goes beyond simple reinforcement theory accounts and suggest possible explanations for how peers may motivate adolescent behavior.     

Impact of action planning on spatial perception: Attention matters

Previous research suggested that perception of spatial location is biased towards spatial goals of planned hand movements. In the present study I show that an analogous perceptual distortion can be observed if attention is paid to a spatial location in the absence of planning a hand movement. Participants judged the position of a target during preparation of a mouse movement, the end point of which could deviate from the target by a varying degree in Exp. 1. Judgments of target position were systematically affected by movement characteristics consistent with perceptual assimilation between the target and the planned movement goal. This effect was neither due to an impact of motor execution on judgments (Exp. 2) nor due to characteristics of the movement cues or of certain target positions (Exp. 3, Exp. 5A). When the task included deployment of attention to spatial positions (former movement goals) in preparation for a secondary perceptual task, an effect emerged that was comparable with the bias associated with movement planning (Exp. 4, Exp. 5B). These results indicate that visual distortions accompanying manipulations of variables related to action could be mediated by attentional mechanisms.     

Time course of planning for object and action parameters in visually guided manipulation

Under visual guidance, subjects reached for and manipulated an object that variedin weight and surface texture (slipperiness). The manipulatory action was either grasping, lifting, or posting in a slot. The task was constrained or unconstrained with respect to speed, grasp pattern, and contact force. Initiation time (pre-reach), movement time (reach), and post-contact errors were measured, to examine planning for task performance at three points in time. Results indicate that in the constrained task, the manipulatory action was planned during the initiation time, but planning for object parameters was deferred until the reach interval. With relaxed task constraints, initiation times increased,and texture and manipulatory action had independent effects on premovement planning. Errors were affected interactively by all variables. The results suggest a planning process that unfolds over time, incorporating in turn the manipulatory action, object texture, and object weight. This unfolding accommodates variables proximate to the time where they will affect physical action.     

Evidence for model-based action planning in a sequential finger movement task

In this article, the authors examine whether and how humans use model-free, reflexive strategies and model-based, deliberative strategies in motor sequence learning. They asked subjects to perform the grid-sailing task, which required moving a cursor to different goal positions in a 5 × 5 grid using different key-mapping (KM) rules between 3 finger keys and 3 cursor movement directions. The task was performed under 3 conditions: Condition 1, new KM; Condition 2, new goal position with learned KM; and Condition 3, learned goal position with learned KM; with or without prestart delay time. The performance improvement with prestart delay was significantly larger under Condition 2. This result provides evidence that humans implement a model-based strategy for sequential action selection and learning by using previously learned internal model of state transition by actions.     

Testing the co-existence of two timing strategies for motor control in a unique task: The synchronisation spatial-tapping task

The control of rhythmic action sequences may involve two distinct timing strategies, i.e., event-based and emergent timing, which are usually revealed through finger-tapping and circle-drawing tasks, respectively. There is a lively debate concerning the possibility of coexistence of the two modes of timing for the execution of a single task. If one considers emergent timing as simply an absence of explicit representation of a time interval, then by definition, the two modes of timing cannot coexist. However, if one considers that emergent timing engages control of another motor parameter, e.g., a control of movement through space rather than time, then the possibility of coexistence needs to be reassessed. In the present study, we designed a hybrid of finger-tapping and circle-drawing tasks for which the demands for space and time control were present at the same time in order to reassess the coexistence hypothesis. Seventy-eight participants performed a spatial-tapping task in which finger taps were to be produced in synchrony with a regular metronome to 6 visual targets presented around a virtual circle. The metronome set ten distinct tempi (1100–300 ms). Using autocorrelation analyses on timing variables, we show that motor timing was event-based at slow tempi and emergent at faster tempi. Through an analysis of the trajectory, we confirm that an increase in the spatial control of movement took place congruently with a switch from event-based to emergent timing modes. At these fast tempi, timing and spatial errors were correlated but only at the specific target location for which a dynamical anchor point was revealed. Hence, we conclude that the coding of emergent timing has a spatial nature from which emerge timing regularities. This spatio-temporal strategy insures the performance of sequential motor actions when cognitive effort is too high for the use of pure event-based timing strategies.