Impulse and Movement Space-Time Variability

In 3 experiments, the authors examined movement space-time variability as a function of the force-time properties of the initial impulse in a movement timing task. In the range of motion and movement time task conditions, peak force, initial rate of force, and force duration were manipulated either independently or in combination across a range of parameter values. The findings showed that (a) impulse variability is predicted well by the elaboration of the isometric force variability scaling functions of L. G. Carlton, K. H. Kim, Y. T. Liu, and K. M. Newell (1993) to movement, and (b) the movement spatial and temporal outcome variability are complementary and well predicted by an equation treating the variance of force and time in Newton's 2nd law as independent random variables. Collectively, the findings suggest that movement outcome variability is the product of a coherent space-time function that is driven by the nonlinear scaling of the force-time properties of the initial impulse.     

Formula: see text]Executive functions in extremely low birth weight and late-preterm preschoolers: Effects on working memory and response inhibition

Executive function (EF) refers to fundamental capacities that underlie more complex cognition and have ecological relevance across the individual's lifespan. However, emerging executive functions have rarely been studied in young preterm children (age 3) whose critical final stages of fetal development are interrupted by their early birth. We administered four novel touch-screen computerized measures of working memory and inhibition to 369 participants born between 2004 and 2006 (52 Extremely Low Birth Weight [ELBW]; 196 late preterm; 121 term-born). ELBW performed worse than term-born on simple and complex working memory and inhibition tasks and had the highest percentage of incomplete performance on a continuous performance test. The latter finding indicates developmental immaturity and the ELBW group's most at-risk preterm status. Additionally, late-preterm participants performed worse compared with term-born on measures of complex working memory but did not differ from those term-born on response inhibition measures. These results are consistent with a recent literature that identifies often subtle but detectable neurocognitive deficits in late-preterm children. Our results support the development and standardization of computerized touch-screen measures to assess EF subcomponent abilities during the formative preschool period. Such measures may be useful to monitor the developmental trajectory of critical executive function abilities in preterm children, and their use is necessary for timely recognition of deficit and application of appropriate interventional strategies.     

Visual feedback of hand trajectory and the development of infant prehension

The purpose of this longitudinal infant study was to investigate the influence of visual information of the hand trajectory in the development of reaching movements in prehension. Ten infants were observed biweekly from the age of 10 weeks to 28 weeks and 1 yr. The reach kinematics were analyzed at age of reach onset, 6 mo and 1 yr of age. The results showed that infants reached for objects earlier when the visual feedback of the hand trajectory and the object were available. However, visual feedback of the hand trajectory did not change the movement speed and smoothness of the reach component at 6 mo and 1 yr of age. Infants reached for the larger object earlier and with higher velocity than for the smaller object. Visual feedback of the hand facilitates the age of reaching onset, but when the reaching movements become sufficiently stable, infants perform equally well with or without visual trajectory feedback of the hand.     

Self-organized criticality and learning a new coordination task

The purpose of this study was to investigate the hypothesis that a self-organized criticality (SOC) practice condition would have a higher improvement rate in performance outcome than a typical progressive difficulty of practice regimen. The roller ball task was used where participants undergo a phase transition from failure to successful performance after sufficient practice. The findings from two experiments showed that the SOC condition had the fastest rate of improvement and the highest performance success level. The success probability in the SOC practice regime was close to the theoretically predicted value of 50%. It appears that the SOC practice condition - by scaling task difficulty to skill level in a self-controlled adaptive strategy - facilitates the learning of new movement coordination pattern by keeping the participant close to the parameter region of the transition of the movement dynamics.     

Feature-based versus category-based induction with uncertain categories

Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is known. The present experiments examined the conditions that drive feature-based and category-based strategies in induction under category uncertainty. Specifically, 2 experiments investigated whether reliance on feature-based inductive strategies is a product of the lack of coherence in the categories used in previous research or is due to the use of a decision-only induction procedure. Experiment 1 found that feature-based reasoning remained the preferred strategy even when categories with relatively high internal coherence were used. Experiment 2 found a shift toward category-based reasoning when participants were trained to classify category members prior to feature induction. Together, these results suggest that an appropriate conceptual representation must be formed through experience with a category before it is likely to be used as a basis for feature induction.     

Fabricated Illness: Working within the Family System to Find a Pathway to Health

The term medically unexplained symptoms refers to a clinical presentation where the child's symptoms and impairment cannot be explained by any known organic pathology, and may include conversion disorders, somatoform pain disorders, factitious disorder, and factitious disorder by proxy. In this case study, we present our treatment of a 9‐year‐old girl with a 2‐year history of medically unexplained abdominal cramping and vaginal discharge. During the 9 months that we worked with this family, we were never able to clarify in our own minds the source of the child's symptoms—that is, who was responsible for their induction or who was the instigator or maintainer of the exaggerated symptoms. Nor did we come to fully understand the function of the symptoms in the family system. Our case report does not answer either of these questions. Instead, we describe how we worked with the family despite the ongoing ambiguities as to why the symptoms were occurring and who was inducing them. The functional outcome was disappearance of symptoms, return to full school attendance, and improved parenting behavior.     

Stuttering severity and educational attainment

Purpose

This study investigated the relationship between self-reported stuttering severity ratings and educational attainment.

Method

Participants were 147 adults seeking treatment for stuttering. At pretreatment assessment, each participant reported the highest educational level they had attained and rated their typical and worst stuttering severity on a 9-point scale for a range of speaking situations. These included: (1) talking with a family member, (2) talking with a familiar person, not a family member, (3) talking in a group of people, (4) talking with a stranger, (5) talking with an authority figure such as a work manager or teacher, (6) talking on the telephone, (7) ordering food or drink, and (8) giving their name and address.

Results

There was a significant negative relationship between highest educational achievement and mean self-reported stuttering severity rating for the eight situations.

Conclusions

Future research is needed to investigate how this result should be addressed in educational institutions.Educational objectives: The reader will be able to: (1) describe the negative effects of stuttering through childhood to adulthood; (2) identify some of the negative consequences associated with stuttering on peer and teacher relationships, and academic performance at school; and (3) summarise the relationship between stuttering severity and educational attainment.     

Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps

The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7–12, participants were required to completely exhaust their calves with the aid of additional weights (44.4 ± 8.8 kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual’s calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen.     

Jandu Yani U (for all families): Tailored Triple P Training and Support Promote Empowerment in Remote Aboriginal Communities

Journal of Child and Family Studies - To enhance the accessibility and acceptability of evidence-based parenting programs in Indigenous communities, there is a need to build a confident and skilled...