Differences in postural control and movement performance during goal directed reaching in children with developmental coordination disorder

Poor upper-limb coordination is a common difficulty for children with developmental coordination disorder (DCD). One hypothesis is that deviant muscle timing in proximal muscle groups results in poor postural and movement control. The relationship between muscle timing, arm motion and children's upper-limb coordination deficits has not previously been studied. The aim of this study was to investigate the relationship between functional difficulties with upper-limb motor skills and neuromuscular components of postural stability and coordination. Sixty-four children aged 8-10 years, 32 with DCD and 32 without DCD, participated in the study. The study investigated timing of muscle activity and resultant arm movement during a rapid, voluntary, goal-directed arm movement. Results showed that compared to children without DCD, children with DCD took significantly longer to respond to visual signals and longer to complete the goal-directed movement. Children with DCD also demonstrated altered activity in postural muscles. In particular, shoulder muscles, except for serratus anterior, and posterior trunk muscles demonstrated early activation. Further, anterior trunk muscles demonstrated delayed activation. In children with DCD, anticipatory function was not present in three of the four anterior trunk muscles. These differences support the hypothesis that in children with DCD, altered postural muscle activity may contribute to poor proximal stability and consequently poor arm movement control when performing goal-directed movement. These results have educational and functional implications for children at school and during activities of daily living and leisure activities and for clinicians assessing and treating children with DCD.     

Women in child development: themes from the SRCD Oral History Project

Research in child development has emerged as a major intellectual discipline and a topic of great interest and importance to society. The Society for Research in Child Development (SRCD) has been the leading scholarly society concerned with the advancement of this research. As part of its focus on a history of the field, the SRCD has undertaken an oral history project in which prominent members are interviewed. Of the 102 completed interviews, 47 are women's accounts, which document important contributions women have made to child development. The experiences reported by individual participants reflect themes in the general history of women in psychology and child development during the early and mid-1900s. Women encountered obstacles to their efforts, even as they were supported by others and struggled to achieve prominence amid the sometimes ambiguous or conflicting circumstances that characterized women's entry into child development.     

A developmental dissociation in reinstatement of an extinguished fear response in rats

Recently, studies from our laboratory have shown that 16-day-old rats, in contrast to 23-day-old rats, fail to show either ABA renewal or recovery of an extinguished fear response following a pre-test injection of FG7142 [Kim, J. H. & Richardson, R. (2007). A developmental dissociation of context and GABA effects on extinguished fear in rats. Behavioral Neuroscience; Yap & Richardson, unpublished data]. The present study, using freezing as a measure of learned fear, extends these findings by examining whether there is a developmental difference in susceptibility to reinstatement following extinction. 16- and 23-day-old rats were trained to fear a white-noise conditioned stimulus (CS) by pairing it with a shock unconditioned stimulus (US). This fear was subsequently extinguished by non-reinforced presentations of the CS. Some rats received a post-extinction Reminder which consisted of a single presentation of a reduced-intensity US. Experiments 1 and 2 demonstrated that this Reminder was effective in reinstating extinguished fear in 23-day-olds, and that this reinstatement effect was context-specific in rats this age. In contrast, 16-day-old rats failed to show the reinstatement effect in either experiment. The failure to observe a post-extinction reinstatement effect in the 16-day-olds was not due to a general ineffectiveness of the Reminder treatment at this age because it did alleviate spontaneous forgetting in rats this age (Experiment 3). Taken together, the results suggest that fundamentally different processes may mediate extinction early in development compared to later in development.     

Development of action monitoring through adolescence into adulthood: ERP and source localization

In this study we examined the development of three action monitoring event-related potentials (ERPs) - the error-related negativity (ERN/Ne), error positivity (P(E)) and the N2 - and estimated their neural sources. These ERPs were recorded during a flanker task in the following groups: early adolescents (mean age = 12 years), late adolescents (mean age = 16 years), and adults (mean age = 29 years). The amplitudes of the ERN/Ne and N2 were greater in the adult and late adolescent groups than in the early adolescent group. Both of these components had neural sources in the anterior cingulate cortex (ACC). Although P(E) was present across groups, P(E) amplitude was greater in the late adolescent group compared to the adult group and also had neural sources in the ACC. ERN/Ne amplitude was related to post-error slowing across age groups; it was related to task performance only in the adult group. These findings are discussed in light of the role of the maturation of the ACC in the development of action monitoring processes.     

Psychological norms for simple three-line graphic shapes

There is a longstanding tradition in psychological research for norming lists of words that are used in experimental studies. The present study extends this practice to graphic imagery by obtaining norming data on 24 simple abstract graphic shapes composed of three straight-line segments. The attributes obtained in the norming procedure were the shapes' familiarity, describability, associability, availability, and potential for word association. Results from rating data indicate significantly different, yet reliable, responses by participants to the various shape configurations. Multidimensional scaling analysis of shape ratings identified two underlying dimensions of perceived differences: the continuity of a shape's linear direction and the consistency or regularity of its interior angles. By contrast, performance in generating word associations for figures appeared to be linguistically driven, with initial responses related to the similarity of shapes to letters of the alphabet. The norms and the computer program used to collect them can be downloaded from www.psychonomic.org/archive.     

Social Neuroscience: Progress and Implications for Mental Health

ABSTRACT— Social neuroscience is a new, interdisciplinary field devoted to understanding how biological systems implement social processes and behavior. Social neuroscience capitalizes on biological concepts and methods to inform and refine theories of social behavior, and it uses social and behavioral constructs and data to inform and refine theories of neural organization and function. We focus here on the progress and potential of social neuroscience in the area of mental health. Research in social neuroscience has grown dramatically in recent years. Among the most active areas of research we found are brain-imaging studies in normal children and adults; animal models of social behavior; studies of stroke patients; imaging studies of psychiatric patients; and research on social determinants of peripheral neural, neuroendocrine, and immunological processes. We also found that these areas of research are proceeding along largely independent trajectories. Our goals in this article are to review the development of this field, examine some currently promising approaches, identify obstacles and opportunities for future advances and integration, and consider how this research can inform work on the diagnosis and treatment of mental disorders.     

Social identities and intergroup bias in immigrant and nonimmigrant children

Ethnic and American identity, as well as positivity and negativity toward multiple social groups, were assessed in 392 children attending 2nd or 4th grade in various New York City neighborhoods. Children from 5 ethnic groups were recruited, including White and Black Americans, as well as recent immigrants from China, the Dominican Republic, and the former Soviet Union. For ethnic minority children, greater positivity bias (evaluating one's ingroup more positively than outgroups) was predicted by immigrant status and ethnic identity, whereas negativity bias (evaluating outgroups more negatively than one's ingroup) was associated with increased age, immigrant status, and (among 4th graders only) ethnic identity. In addition, a more central American identity was associated with less intergroup bias among ethnic minority children.     

Recognition of nonverbal affect and schizotypy

The authors assessed the degree to which schizotypal characteristics in a nonclinical population were associated with impairments in the ability to correctly identify emotions as expressed in facial, paralinguistic, and postural cues. Participants completed the Schizotypal Personality Questionnaire (SPQ; A. Raine, 2005), and the 3 receptive subtests of the Diagnostic Analysis of Nonverbal Accuracy-2 (DANVA2; S. Nowicki Jr., 2005). The SPQ subscales No close friends and Suspiciousness were correlated with impaired ability to correctly identify postural affective cues on the DANVA2. Unusual perceptual experiences were correlated with deficits in the ability to identify emotions on the DANVA2 paralinguistic measure. Impairments in the ability to correctly perceive and respond to expressions of affect may be part of a deficit in social cognition that contributes to development of schizotypal traits.