Age Differences on a Coincident Anticipation Task

Two experiments were performed as an initial attempt to explain age related limitations in response accuracy on a coincident anticipation task. Five- to 9-year-old boys and adult males participated in each experiment. They made horizontal arm movements in response to stimuli from a Bassin Anticipation Timer. The results of Experiment I confirmed the findings of previous studies, which showed that young children respond early to slow moving stimuli. They were most accurate at intermediate speeds; their responses deteriorated as speed was increased. Older children and adults were more accurate at slow to intermediate speeds; their performances also declined at fast stimulus velocities. Experiment II examined use of a stereotypic or default movement speed as an explanation for these results, particularly for young children. A most comfortable movement pace was determined for each subject and was used as a baseline speed for a subsequent timing task. Four other stimuli were selected in 0.8 mph increments from the baseline speed (two faster, two slower). In addition, selected trials for 6 subjects at each age were filmed at 32 fps. X-coordinates for these trials were obtained and smoothed at 5 Hz. Movement time data suggested that 5-year-olds used a preferred or stereotypic speed, since they were accurate only when responding to their baseline speed. Older subjects matched stimuli up to and including their baselines. Kinematic characteristics confirmed the general notion of preferred speed for 5-year-olds. These same measures demonstrated that older subjects were increasingly adaptable in their responses, despite a failure to respond more accurately. Consequently, the term “preferred speed” lacks generality as an explanatory concept. Age-related shifts in the ability to modify components of a response, like average movement velocity and number of corrections, were used to explain accuracy differences.     

Age difference on a coincident anticipation task: influence of stereotypic or "preferred" movement speed

Two experiments were performed as an initial attempt to explain age related limitations in response accuracy on a coincident anticipation task. Five- to 9-year-old boys and adult males participated in each experiment. They made horizontal arm movements in response to stimuli from a Bassin Anticipation Timer. The results of Experiment l confirmed the findings of previous studies, which showed that young children respond early to slow moving stimuli. They were most accurate at intermediate speeds; their responses deteriorated as speed was increased. older children and adults were more accurate at slow to intermediate speeds; their performances also declined at fast stimulus velocities. Experiment ll examined use of a stereotypic or default movement speed as an explanation for these results, particularly for young children. A most comfortable movement pace was determined for each subject and was used as a baseline speed for a subsequent timing task. Four other stimuli were selected in 0.8 mph increments from the baseline speed (two faster, two slower). In addition, selected trials for 6 subjects at each age were filmed at 32 fps. X-coordinates for these trials were obtained and smoothed at 5 Hz. Movement time data suggested that 5-year-olds used a preferred or stereotypic speed, since they were accurate only when responding to their baseline speed. older subjects matched stimuli up to and including their baselines. Kinematic characteristics confirmed the general notion of preferred speed for 5-year-olds. These same measures demonstrated that older subjects were increasingly adaptable in their responses, despite a failure to respond more accurately. Consequently, the term "preferred speed" lacks generality as an explanatory concept. Age-related shifts in the ability to modify components of a response, like average movement velocity and number of corrections, were used to explain accuracy differences.     

Developmental Features of Rapid Aiming Arm Movements Across the Lifespan

Using a lifespan approach, the authors investigated developmental features of the control of ballistic aiming arm movements by manipulating movement complexity, response uncertainty, and the use of precues. Four different age groups of participants (6- and 9-year-old boys and girls and 24- and 73-year- old men and women, 20 participants in each age group) performed 7 types of rapid aiming arm movements on the surface of a digitizer. Their movement characteristics such as movement velocity, normalized jerk, relative timing, movement linearity, and intersegment intervals were profiled. Analyses of variance with repeated measures were conducted on age and task effects in varying movement complexity (Study 1), response uncertainty (Study 2), and precue use (Study 3) conditions. Young children and senior adults had slower, more variant, less smooth, and less linear arm movements than older children and young adults. Increasing the number of movement segments resulted in slower and more variant responses. Movement accuracy demands or response uncertainty interacted with age so that the 6- and 74-year-old participants had poorer performances but responded similarly to the varying treatments. Even though older children and young adults had better performances than young children and senior adults, their arm movement performance declined when response uncertainty increased. The analyses suggested that young children's and senior adults' performances are poorer because less of their movement is under central control, and they therefore use on-line adjustments. In addition, older children and young adults use a valid precue more effectively to prepare for subsequent movements than do young children and senior adults, suggesting that older children and young adults are more capable of organizing motor responses than arc young children and senior adults.     

Developmental features of rapid aiming arm movements across the lifespan

Using a lifespan approach, the authors investigated developmental features of the control of ballistic aiming arm movements by manipulating movement complexity, response uncertainty, and the use of precues. Four different age groups of participants (6- and 9-year-old boys and girls and 24- and 73-year-old men and women, 20 participants in each age group) performed 7 types of rapid aiming arm movements on the surface of a digitizer. Their movement characteristics such as movement velocity, normalized jerk, relative timing, movement linearity, and intersegment intervals were profiled. Analyses of variance with repeated measures were conducted on age and task effects in varying movement complexity (Study 1), response uncertainty (Study 2), and precue use (Study 3) conditions. Young children and senior adults had slower, more variant, less smooth, and less linear arm movements than older children and young adults. Increasing the number of movement segments resulted in slower and more variant responses. Movement accuracy demands or response uncertainty interacted with age so that the 6- and 74-year-old participants had poorer performances but responded similarly to the varying treatments. Even though older children and young adults had better performances than young children and senior adults, their arm movement performance declined when response uncertainty increased. The analyses suggested that young children's and senior adults' performances are poorer because less of their movement is under central control, and they therefore use on-line adjustments. In addition, older children and young adults use a valid precue more effectively to prepare for subsequent movements than do young children and senior adults, suggesting that older children and young adults are more capable of organizing motor responses than are young children and senior adults.     

Oculomotor bias induced by number perception

Previous research with manual response methods has found evidence for an association between numbers and space. The present study investigated whether eye movements also show this association. Eye movement responses were recorded from 15 healthy participants as they categorized the digits 0-9 as odd or even. Responses were initiated faster to the left in response to small digits and faster to the right in response to large digits. Movement amplitudes were not systematically affected by either number magnitude or parity. These results provide further evidence for a spatially oriented "mental number line".     

The preparation of reach-to-grasp movements in adults, children, and children with movement problems

This study explored the use of advance information in the control of reach-to-grasp movements. The paradigm required participants to reach and grasp illuminated blocks with their right hand. Four target blocks were positioned on a table surface, two each side of the mid-saggital plane. In the complete precue condition, advance information precisely specified target location. In the partial precue condition, advance information indicated target location relative to the midsaggital plane (left or right). In the null condition, the advance information was entirely ambiguous. Participants produced fastest responses in the complete precue condition, intermediate response times in the partial condition, and the slowest responses in the null condition. This result was observed in adults and four groups of children including a group aged 4-6 years. In contrast, children with Developmental Coordination Disorder (DCD, n = 11, aged 7-13 years) showed no advantage of partial precueing. Movement duration was determined by target location but was unaffected by precue condition. Movement duration was a clear function of age apart from children in the DCD group who showed equivalent movement times to those of the youngest children. These findings provide important insights into the control of reach-to-grasp movements and highlight that partial cues are exploited by children as young as 4 years but are not used in situations of abnormal development.     

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.     

An extended motor network generates beta and gamma oscillatory perturbations during development

This study examines the time course and neural generators of oscillatory beta and gamma motor responses in typically-developing children. Participants completed a unilateral flexion–extension task using each index finger as whole-head magnetoencephalography (MEG) data were acquired. These MEG data were imaged in the frequency-domain using spatial filtering and the resulting event-related synchronizations and desynchronizations (ERS/ERD) were subjected to voxel-wise statistical analyses to illuminate time–frequency specific activation patterns. Consistent with adult data, these children exhibited a pre-movement ERD that was strongest over the contralateral post-central gyrus, and a post-movement ERS response with the most prominent peak being in the contralateral precentral gyrus near premotor cortices. We also observed a high-frequency (∼80 Hz) ERS response that coincided with movement onset and was centered on the contralateral precentral gyrus, slightly superior and posterior to the beta ERS. In addition to pre- and post-central gyri activations, these children exhibited beta and gamma activity in supplementary motor areas (SMA) before and during movement, and beta activation in cerebellar cortices before and after movement. We believe the gamma synchronization may be an excellent candidate signal of basic cortical motor control, as the spatiotemporal dynamics indicate the primary motor cortex generates this response (and not the beta oscillations) which is closely yoked to the initial muscle activation. Lastly, these data suggest several additional neural regions including the SMA and cerebellum are involved in basic movements during development.     

Development and validation of the Movement Imagery Questionnaire for Children (MIQ-C)

The ability to perform movement imagery has been shown to influence motor performance and learning in sports and rehabilitation. Self-report questionnaires have been developed to assess movement imagery ability in adults, such as the Movement Imagery Questionnaire 3 (MIQ-3); however, there is a dearth of developmentally appropriate measures for use with children. To address this gap, the focus of this research was to develop an imagery ability questionnaire for children. This process involved adaptation of the MIQ-3 via: i) cognitive interviewing with twenty children, ii) validation with 206 children by examining its factor structure via multitrait-multi method confirmatory factor analysis, and iii) examination of test-retest reliability with 23 children. The findings of Study 1 led to changes to the wording of the questionnaire and modifications of the instructions to successfully adapt the MIQ-3 for children aged 7–12 years. The validation undertaken in Study 2 found that a correlated-traits correlated-uniqueness model provided the best fit to the data. Finally, test-retest reliabilities varied from fair (for external visual imagery) to substantial (for kinesthetic imagery). With respect to ease of imaging, no significant gender or age-group differences were noted. However, significant difference were found among the three imagery modalities (p < .001), with external visual imagery rated as easiest to image and kinesthetic imagery rated as the most difficult. Taken together, findings support the use of the MIQ-C for examining movement imagery ability with children.     

The interaction of tactile information and movement amplitude in a multijoint bimanual circle-tracing task: Phase transitions and loss of stability

Adaptive behaviour in bimanual coordination was examined with the use of a bimanual circle-tracing task. Circle diameter and tactile information were manipulated to form four tracing conditions: tracing a pair of 3-cm diameter circles with the tips of the index fingers (3F) or hand-held styli (3S) and tracing a pair of 10-cm diameter circles with the tips of the index fingers (10F) or hand-held styli (10S). Movement frequency was increased in all conditions. In the 3F, 3S, and 10S tracing conditions, an abrupt transition from asymmetric to symmetric coordination was the main adaptive response, while in the 10F tracing condition, phase wandering was the main adaptive response. Enhancement of fluctuations in relative phase, a signature of loss of stability, occurred before the transition from asymmetric to symmetric coordination. Movement frequency and movement amplitude interact as control parameters in this task. The results are discussed with reference to tactile surface contact and joint motion as sources of sensory information that can be used to stabilize bimanual coordination patterns. The presence or absence of tactile information is directly linked to the specific form of adaptive behaviour (phase transition or phase wandering) that emerges as a function of required movement amplitude and required pacing frequency.     

Movement competence: Association with physical self-efficacy and physical activity

BackgroundThe purpose of this paper was to investigate whether physical self-efficacy mediates the relationship between movement competence (fundamental movement skills and perceived movement skill competence) and physical activity in children.MethodsA purposive sample of 860 children (47.7% female, 10.9 ± 1.16 years) were recruited and completed assessments for physical self-efficacy (Physical Activity Self-Efficacy Scale), fundamental movement skills (Test of Gross Motor Development-3), perceived movement skill competence (Pictorial Scale of Perceived Movement Skill Competence), and physical activity (PACE+). A bootstrap mediation analysis was employed using movement competence as the predictor variable and physical activity as the outcome variable, and physical self-efficacy as the potential mediator of the relationship.ResultsThe results from a bootstrap mediation analysis yielded a statistically significant mediation effect for physical self-efficacy, with the entire model explaining approximately 10.3% of the variance of physical activity. The indirect effect of perceived movement skill competence through physical self-efficacy was significantly larger than the indirect effect of fundamental movement skills through physical self-efficacy. Neither sex nor age acted as a covariate.ConclusionMovement competence (fundamental movement skills and perceived movement skill competence) acts as a source of information for children's physical self-efficacy, moreover physical self-efficacy mediates the movement competence – PA relationship. Findings highlight the need for interventions to target and improve movement competence as a whole for children.     

Amending movements: the relationship between degree of mechanical disturbance and outcome accuracy

This paper examines the relationship between the degree of a mechanical disturbance, outcome accuracy, and amendment times to produce response corrections. Movement time error and amendment times were generated by systematically increasing the duration of acceleration and deceleration perturbations. Subjects produced discrete timing responses (700 msec-70 degrees) during which perturbations were interjected into the ongoing movement on random trials. Amendment times were generated from acceleration curves along with a number of related kinematic parameters (e.g., Movement Time, Peak Acceleration). The results showed that as the degree of the mechanical disturbance increased, timing error and amendment times to the perturbations also increased. At low force levels, the percentage of accurate responses to a decelerating perturbation was approximately equal to the percentage of accurate responses for control trials. As force level increased, however, timing error increased and the percentage of accurate responses decreased. in addition, as the magnitude of the disturbance increased, changes occurred in the kinematic properties of the perturbed movements which contributed toward the degree of outcome accuracy of the response. Collectively, the results are discussed in relation to an error correction system that operates in an interactive fashion based on the characteristics of the error and the constraints of the task.     

Reaction time and index of difficulty in target-striking tasks with changes in direction

Reaction time (RT) for two three-segment target-striking responses involving changes in direction of movement was studied as a function of differences in their additive index . . . index of difficulty (A-ID). In one condition the A-ID was 9.96 and in the other, 6.76. For 16 right-handed university students, mean RT was significantly faster for the condition in which the index was 6.76. Movement times were consistent with Fitts' Law. The data support Sidaway, Christina, and Shea's 1988 prediction that for target-striking movements with changes of direction, RT is a function of the cumulative series of movement constraints.     

Temporal and spatial parameters of stepping in place in children and adults

Characteristics of synchronized and self-paced stepping in place were examined by analyzing a temporal parameter (step frequency) and a spatial parameter (step height). Participants were 20 adults (10 women, 10 men; M age = 22.5 yr., range = 21-23) and 10 children (5 girls, 5 boys; M age=6.1 yr., range = 5-6). Results indicated that: (1) the step frequencies, which were equivalent for both groups, were well coincident with stimulus frequencies; (2) when step frequencies were imposed, the step height decreased with increasing step frequency, except for the lowest frequency condition in children; (3) movement consistency was the highest at 2 Hz and deteriorated if the step frequency was higher or lower; and (4) the self-paced stepping in place was optimal in terms of movement consistency. These results showed that stepping in place is a rhythmic movement at a given range of frequency which is coordinated so as to keep the product of step frequency and step height constant.     

Fine points aside: data are data

Movement responses by 5 1/2- to 6 1/2-year-old children on the Holtzman Inkblot Test were reported on by Lockwood et al. in volume 45 of this Journal. Criticism of the findings discussed in that article by J. Swartz, Reinehr, and C. Swartz was published in the December, 1981, volume of the Journal. The present article rebuts their criticism and emphasizes the significance of the original findings which reflect new and highly discrepant normative M response data from that previously available.     

Reliability and validity of children's reports of migraine headache symptoms

The present study was concerned with whether children's responses to a questionnaire correspond with parents' reports of the child's headache symptoms and whether these responses correlate with self-monitored headache activity. Twenty-eight children, ages 7 years–16 years, participated in the study. Using a questionnaire format, data on a wide variety of headache characteristics were gathered from parents and children. During the subsequent 4 weeks, children monitored their headache activity and medication usage. Results were generally supportive of the validity and reliability of children's reports via a questionnaire format. The responses to the frequency of headache and medication usage were found to predict the responses over the next month, whereas the response on the duration of headache did not. Significant correlations for most headache-symptom items indicated that children and parents agree on their presence and severity. This investigation is the first step in developing a systematic assessment procedure for childhood headache.     

Target-size influences on reaction time with movement time controlled

The variable that affect motor programming time may be studied by changing the nature of the response and measuring the subsequent changes in reaction time (RT). One notion of motor programming suggests that aiming responses with reduced target size and/or increased target amplitude require more "complex" motor programs that require longer RTs. In a series of five experiments which movement time (MT) was experimentally varied target size neither influences RT when the movement amplitude was 2 or 30 cm nor when the target sizes differed by as much as a factor of 16:1. Increasing the movement amplitude from 15 to 30 cm also had no influence on RT. Movement time, however, did affect RT, with 200-msec movements having longer RTs than 120-msec movements. Target size and movement amplitude did not appear to be factors that influence programming time or program complexity.     

Reaching for words and nonwords: Interactive effects of word frequency and stimulus quality on the characteristics of reaching movements

Word frequency and stimulus degradation produce large and additive effects in the onset latencies of lexical decision responses. The influence of these two variables was examined in a lexical decision task where continuous arm-reaching responses were required and movement trajectories were tracked. The results yielded the typical additive pattern of word frequency and stimulus degradation on reaction time and movement duration. Importantly, however, an examination of movement trajectories revealed interactive effects of word frequency and stimulus degradation that emerged for the early part of the movement. These findings suggest that factors thought to influence early stages of stimulus identification continue to influence the dynamics of the response after response initiation, motivating a need to reevaluate current models of lexical decision performance. Moreover, this work highlights how the dynamics of naturalistic multidimensional responses provide a richer source of information about decision-making processes than do discrete unidimensional measures.     

What is the revised Fear Survey Schedule for Children measuring?

This study was designed to investigate parameters of children's fear in terms of frequency of fearful thoughts and avoidance behaviour. It is suggested that current measures such as the Fear Survey Schedule for Children--Revised (FSSC-R) do not assess fearful behaviour in the sense of the occurrence of fearful responding in daily life, but rather reflect a negative affective response to the thought of occurrence of specific events. A modified version of the FSSC-R examined the frequency of fearful thoughts/feelings and avoidance activities amongst 376 children aged 7-12 yr. Contrary to predictions, it was found that children reported high levels of fearful thoughts and avoidance behaviour to those items identified as the greatest fears on the FSSC-R, namely fears of injury, illness, death and danger. These events were typically of low probability (e.g. earthquakes) and the question was raised as to what children are responding to when they are asked to rate their fearful responses. The same pattern of results was reflected in older compared to younger children. It is suggested that even when children are asked to rate frequency of fearful thoughts or avoidance behaviour, they tend to respond to fear questionnaire items according to their affective response to the image or thought of the stimulus situation rather than their actual fear responses. Both the FSSC-R and the modified version were found to discriminate between teacher nominated high and low fearful children and to correlate significantly with a self report measure of anxiety.     

An exploratory study of the kinematics of girls with Turner Syndrome in a visuo‐motor task

In this paper a study is reported in which a group of children with Turner Syndrome (TS) is compared on motor performance tests and real‐time kinematic data with a control group. The objective of this study was to identify possible kinematic variables that characterize the movement patterns utilized by this group of children in achieving their optimal performance. The underlying idea is that by comparing test results and movement kinematics one might gain more insight into the movement production of children than by just looking at the test results or by just using clinical movement observation. The children performed a pen and paper task, the flower trail (one of the sub‐tests of the Movement ABC) (Henderson and Sugden, 1992), on an XY‐tablet. We explored kinematic variables, such as trajectory length, movement time, velocity and pen pressure. It was found that, although girls with TS have a severe motor deficit, they are able to draw a line accurately between two narrow boundaries just as well as the control children (no significant difference in mean number of spatial errors). However, quantitative analysis revealed that girls with TS made a large amount of deviations from the optimal path such that their trajectory length increased with more than 10% per flower trail compared to the control group children. They also made more pen lifts and more changes in velocity. The study showed that children from the two groups may reach the same basic accuracy performance level by using very different strategies. Kinematic registration of fine motor tasks holds promise in gaining more insight into how clinical groups cope with their specific motor problems. Copyright © 2003 John Wiley & Sons, Ltd.