Performance variability and affordance perception: practice effects on perceptual judgments for walking versus throwing.

To judge whether an action is possible, people must perceive "affordances"-the fit between features of the environment and aspects of their own bodies and motor skills that make the action possible or not. But for some actions, performance is inherently variable. That is, people cannot consistently perform the same action under the same environmental conditions with the same level of success. Decades of research show that practice performing an action improves perception of affordances. However, prior work did not address whether practice with more versus less variable actions is equally effective at improving perceptual judgments. Thirty adults judged affordances for walking versus throwing a beanbag through narrow doorways before and after 75 practice trials walking and throwing beanbags through doorways of different widths. We fit a "success" function through each participant's practice data in each task and calculated performance variability as the slope of the function. Performance for throwing was uniformly more variable than for walking. Accordingly, absolute judgment error was larger for throwing than walking at both pretest and posttest. However, absolute error reduced proportionally in both tasks with practice, suggesting that practice improves perceptual judgments equally well for more and less variable actions. Moreover, individual differences in variability in performance were unrelated to absolute, constant, and variable error in perceptual judgments. Overall, results indicate that practice is beneficial for calibrating perceptual judgments, even when practice provides mixed feedback about success under the same environmental conditions.

From description to generalization, or there and back again.

In his target article, Yarkoni prescribes descriptive research as a potential antidote for the generalizability crisis. In our commentary, we offer four guiding principles for conducting descriptive research that is generalizable and enduring: (1) prioritize context over control; (2) let naturalistic observations contextualize structured tasks; (3) operationalize the target phenomena rigorously and transparently; and (4) attend to individual data.

Practice and proficiency: Factors that facilitate infant walking skill.

Infant walking skill improves with practice-crudely estimated by elapsed time since walk onset. However, despite the robust relation between elapsed time (months walking) and skill, practice is likely constrained and facilitated by infants' home environments, sociodemographic influences, and spontaneous activity. Individual pathways are tremendously diverse in the timing of walk onset and the trajectory of improvement, and presumably, in the amount and type of practice. So, what factors affect the development of walking skill? We examined the role of months walking, walk onset age, spontaneous locomotor activity, body dimensions, and environmental factors on the development of walking skill in two sociodemographically distinct samples (ns = 38 and 44) of 13-, 15-, and 19-month-old infants. Months walking best predicted how well infants walked, but environmental factors and spontaneous activity explained additional variance in walking skill. Specifically, less crowded homes, a larger percentage of time in spontaneous walking, and a smaller percentage of short walking bouts predicted more mature walking. Walk onset age differed by sample but did not affect walking skill. Findings indicate that elapsed time since walk onset remains a robust predictor of walking skill, but environmental factors and spontaneous activity also contribute to infants' practice, thereby affecting walking skill.

Perceived Barriers Before and After a 3-Month Period of Modified Ride-On Car Use.

PURPOSE: The purpose of the study is to examine how perceived barriers change before and after a 3-month period of modified ride-on car use. METHODS: This study used a qualitative content analysis of perceived barriers. Fourteen caregivers (13 mothers; 1 grandmother) responded to a single-question, free-response survey before and after a 3-month period of modified ride-on car use. RESULTS: A total of 11 and 20 perceived barriers were reported before and after the 3-month period. Environmental barriers were the most frequently reported before and after the 3-month period. CONCLUSIONS: Pediatric physical therapists need to be aware of the potential perceived barriers that families may experience in regard to young children with disabilities using modified ride-on cars and determine strategies to support families on an individual basis.

Perceived Barriers of Modified Ride-On Car Use of Young Children With Disabilities: A Content Analysis.

PURPOSE: Modified ride-on cars have emerged as an early powered mobility option for young children with disabilities. The purpose of this study was to identify, extract, and synthesize perceived barriers of modified ride-on car use reported in previous studies. METHODS: This study was descriptive using a qualitative content analysis of previously published studies identified from a systematic literature search. RESULTS: Categories of perceived barriers were identified: device, environmental, child-related perceived barriers regarding health, tolerance, and abilities, and caregiver-related perceived barriers regarding physical requirements, time, and motivation. Device and environmental perceived barriers were the most reported. CONCLUSIONS: Pediatric physical therapists play a critical role in working with families to promote their self-efficacy for using the modified ride-on car and their capacity for overcoming the inherent difficulties associated with use. Most of the reported perceived barriers are modifiable, at least to some degree, with likely effects on modified ride-on car use.

Standing Tall: Feasibility of a Modified Ride-On Car That Encourages Standing.

PURPOSE: The purpose of this study was to determine the feasibility of infants with Down syndrome to use a modified ride-on car with seated and standing modes. METHODS: Participants included 4 infants with Down syndrome. Families were asked to provide at least 8 minutes of modified ride-on car driving per day, at least 5 times per week throughout the 9-month intervention. RESULTS AND CONCLUSIONS: Families demonstrated a variety of adherence rates to the intervention. Infants demonstrated independent activation of the modified ride-on car in seated and standing modes and enjoyed driving. The modified ride-on car intervention was feasible and warrants further testing to address barriers that influence adherence to the intervention.

Feasibility of a Modified Ride-on Car Intervention on Play Behaviors during an Inclusive Playgroup.

AIMS: Children with mobility related disabilities often experience limited participation and access to social interactions. An emerging pediatric powered mobility device are modified ride-on cars that provide self-directed mobility experiences to children with disabilities. This study aimed to determine: (1) the feasibility of a modified ride-on car intervention during an inclusive playgroup, (2) the effect of a modified ride-on car intervention on the play behaviors of children with and without mobility related disabilities. METHOD: A single-subject research design was implemented. Thirteen children participated in a weekly inclusive playgroup. The five children with mobility related disabilities were provided modified ride-on cars during the intervention. Children's play behaviors were classified with Howes' Peer Play Scale. Intervention effects were examined using nonoverlap of all pairs (NAP). RESULTS: The intervention was feasible based on participants' good attendance, retention rates, and successful use of modified ride-on cars. Overall children did not experience significant changes in play behaviors, with a few exceptions for decreased solitary, and increased parallel play, and/or direct peer interaction, among children with mobility related disabilities. Future research could examine modified ride-on car use by children with mobility related disabilities focusing on changes in unique play interactions between children with and without disabilities.

Modified Ride-On Car Use by Young Children With Disabilities.

PURPOSE: The purpose of this single-subject case series study is to determine the effect of modified ride-on car use in natural environments on mobility. METHOD: Three children younger than 2 years diagnosed with various disabilities participated in this 24-week study using a modified ride-on car in their home and community. RESULTS: All 3 children demonstrated an ability to independently use the modified ride-on car and enjoyed doing so. Two of the 3 children demonstrated clinically significant gains in mobility skills as measured by the Pediatric Evaluation of Disability Inventory. CONCLUSIONS: Modified ride-on car use is an emerging powered mobility device option for children younger than 2 years. Further research is needed to demonstrate the potential long-term gains of early powered mobility access to young children with disabilities.

The development of gait and mobility: Form and function in infant locomotion.

The development of locomotion can be described by its form (i.e., gait) and its function (i.e., mobility). Both aspects of locomotion improve with experience. Traditional treatises on infant locomotion focus on form by describing an orderly progression of postural and locomotor milestones en route to characteristic patterns of crawling and walking gait. We provide a traditional treatment of gait by describing developmental antecedents of and improvements in characteristic gait patterns, but we highlight important misconceptions inherent in the notion of "milestones". Most critically, we argue that the prevailing focus on gait and milestones fails to capture the true essence of locomotion-functional mobility to engage with the world. Thus, we also describe the development of mobility, including the use of mobility aids for support and propulsion. We illustrate how infants find individual solutions for mobility and how the ability to move cascades into other domains of development. Finally, we show how an integration of gait and mobility provides insights into the psychological processes that make locomotion functional. This article is categorized under: Psychology > Motor Skill and Performance Psychology > Development and Aging.

Variations in infants' physical and social environments shape spontaneous locomotion.

Independent locomotion is associated with a range of positive developmental outcomes, but unlike cognitive, linguistic, and social skills, acquiring motor skills requires infants to generate their own input for learning. We tested factors that shape infants' spontaneous locomotion by observing forty 12- to 22-month-olds (19 girls, 21 boys) during free play. Infants were recruited from the New York City area, and caregivers reported that 25 infants were White, six were Asian, four were Black, and five had multiple races; four were Hispanic or Latino. All infants played in four conditions: two environmental conditions (gross-motor toys, fine-motor toys) crossed with two social conditions (alone, together with a caregiver). Infants moved more in the gross-motor toy conditions than in the fine-motor toy conditions. However, the effect of playing with a caregiver differed by toy condition. In the gross-motor toy conditions, playing with a caregiver did not affect how much infants moved, but in the fine-motor toy conditions, playing with a caregiver further depressed infant locomotion. Infants with more walking experience moved more with gross-motor toys but not with fine-motor toys. Differences in the amount of locomotion between conditions were related to how infants used toys and the interactions between infants and caregivers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Exploratory analysis of a developmentally progressive modified ride-on car intervention for young children with Down syndrome.

BACKGROUND: Children with Down syndrome (DS) may have limited opportunities to engage in self-directed mobility and play due to motor delays. A recent modified ride-on car innovation is the sit-to-stand (STS) model, which incorporates functional standing and walking training with the experience of powered mobility. AIMS: This study aimed to: (1) describe total dosage and daily usage of three modified ride-on car modes (seated, standing, and power-push) by young children with DS; (2) examine the ability of young children with DS to independently activate the modified ride-on car in seated and standing modes; (3) describe the age of onset of selected motor milestones of the sample in comparison to DS norms. MATERIALS AND METHODS: Eight young children with DS (8.6 ± 2.0 months) used three modes of the modified ride-on car over a 9-month intervention. RESULTS: All eight children independently activated the modified ride-on car in seated and standing modes. Most motor milestones were achieved earlier in this sample than expected for DS norms, including the onset of independent walking. CONCLUSIONS AND IMPLICATIONS: The developmentally progressive nature of the intervention and high dosage may have been instrumental in encouraging the onset of independent activation and earlier motor milestones.IMPLICATIONS FOR REHABILITATIONYoung children with Down syndrome were able to achieve independent activation in seated and standing modified ride-on cars.Developmentally progressive modified ride-on car interventions may facilitate motor skill development, but future work utilizing a randomized control group is needed to examine the potential motor developmental benefits of the STS model and power-push mode.The developmentally progressive nature of the intervention may have been instrumental in encouraging the onset of independent switch activation in both seated and standing modes, as well as the high dosage and adherence rates compared to previous studies.

Real World Tracking of Modified Ride-On Car Usage in Young Children With Disabilities.

BACKGROUND: Go Baby Go is a community program that provides modified ride-on cars to young children with disabilities. AIMS: (1) To describe the real world modified ride-on car usage of young children with disabilities; (2) To compare subjectively reported modified ride-on car usage recorded by parents with objectively reported usage based on electronic tracking data. METHODS: 14 young children (1-3 years old) with disabilities used a modified ride-on car for three months. RESULTS: On average, parent-reported activity log data indicated that children used the modified ride-on car for 17.8 minutes per session (SD = 9.9) and 195.1 total minutes (SD = 234.8) over three months. Objective tracking data indicated 16.5 minutes per session (SD = 8.6) and 171.4 total minutes (SD = 206.1) over three months. No significant difference of modified ride-on car usage was found between parent-reported activity log data and objective tracking; yet, the mean absolute difference between tracking methods was 96 minutes (SD = 8.6) and suggests over- or under-reporting of families. Children used the modified ride-on car more in the first half compared to the second half of the three-month period (p < .05). CONCLUSIONS: This study may inform future research studies and local chapters of the Go Baby Go community program.