Target selection difficulty, negative priming, and aging

It has been recently suggested that the presence of identity negative priming effects in old adults could occur when there is substantial processing of the distracting information in a selective attention task (J. M. Kieley & A. A. Hartley, 1997). In three experiments, using a letter identification task, it was found that making target selection more difficult increased the magnitude of the negative priming effect to a similar extent in both young and old adults. Moreover, the size of the negative priming effect did not differ between young and elderly participants. These results are discussed with respect to the issue of age-related deficits in the mechanisms underlying negative priming.     

Imaging high-resolution structure of GFP-expressing neurons in neocortex in vivo

To detect subtle changes in neuronal morphology in response to changes in experience, one must image neurons at high resolution in vivo over time scales of minutes to days. We accomplished this by infecting postmitotic neurons in rat and mouse barrel cortex with a Sindbis virus carrying the gene for enhanced green fluorescent protein. Visualized with 2-photon excitation laser scanning microscopy, infected neurons showed bright fluorescence that was distributed homogeneously throughout the cell, including axonal and dendritic arbors. Single dendritic spines could routinely be resolved and their morphological dynamics visualized. Viral infection and imaging were achieved throughout postnatal development up to early adulthood (P 8-30), although the viral efficiency of infection decreased with age. This relatively noninvasive method for fluorescent labeling and imaging of neurons allows the study of morphological dynamics of neocortical neurons and their circuits in vivo.     

Cross-sectional and longitudinal relations among peer-reported trustworthiness, social relationships, and psychological adjustment in children and early adolescents from the United Kingdom and Canada

Trustworthiness was examined in children and early adolescents from two countries. In Study 1,505 children in the fifth and sixth school years in the United Kingdom (mean age = 9 years 7 months) were tested across an 8-month period. In Study 2,350 sixth- through eighth-grade Canadian children and early adolescents (mean age = 12 years 11 months) were tested across a 1-year period. Participants completed measures assessing trustworthiness (ratings of promise and secret keeping by peer group and also by best friend in Study 1), assertiveness (Study 1), prosocial behavior (Study 2), social relationships (friendships and peer preference), and psychological adjustment (self-esteem, depressive symptoms, and loneliness). Peer-reported trustworthiness was positively associated with, and predicted changes across time in, the number of friendships. The observed relations were found to be statistically independent of peer preference and peer-reported assertiveness or prosocial behavior. Trustworthiness was found to be positively associated with peer preference (Study 1 and Study 2) and psychological adjustment (Study 1).     

Challenging behaviors in young children: the father's role

In this study, the authors examined the parenting practices, developmental expectations, and stress levels of 136 fathers and the challenging and prosocial behaviors of their 1- to 5-year-old children. In addition, the authors systematically addressed fathers' qualitative concerns about their parenting. The authors divided the participants into 4 groups and controlled for family socioeconomic status (SES) and the focus child's gender. Results showed a significantly higher use of corporal and verbal punishment and parenting stress among lower income fathers. Secondary analyses demonstrated a significant effect of paternal disciplinary practices that emphasized the frequent use of corporal and verbal punishment on child behavior problems, regardless of SES level. On a positive note, fathers from both lower and higher SES groups had reasonable developmental expectations for their boys and girls, and they reported similar frequencies of their children's prosocial behavior. The authors discuss the need for early parent education programs that include fathers and that teach specific strategies to address child behavior problems.     

Persistent neuropsychological problems after 7 years of abstinence from recreational Ecstasy (MDMA): a case study

This case study concerns a 26-yr.-old male who had consumed large amounts of Ecstasy seven years previously. He stated that his increasingly intensive use of ecstasy over a 4-yr. period had led to the emergence of multiple psychiatric and psychological problems. Given these problems, he stopped using Ecstasy, but the problems had not resolved despite seven years of abstinence. The neurocognitive profile was very similar to that shown by current heavy Ecstasy users, with deficits in immediate and delayed verbal recall, moderately impaired memory function, but normal expressive language ability and perceptual functioning. Extremely high pathology was evident, including depression and phobic anxiety. Severe problems with sleep and sex were also reported. Further studies involving larger groups of abstinent former users are needed; adverse sequelae associated with intensive Ecstasy use may sometimes be enduring.     

Repetition priming effects from attended vs. ignored single words in a semantic categorization task

The present research examines priming effects from a centrally presented single-prime word to which participants were instructed to either attend or ignore. The prime word was followed by a single central target word to which participants made a semantic categorization (animate vs. inanimate) task. The main variables manipulated across experiments were attentional instructions (attend vs. ignore the prime word), presentation duration of the prime word (20, 50, 80 or 100 ms), prime-target stimulus onset asynchrony (SOA; 300 vs. 800 ms), and temporal presentation of instructions (before vs. after the prime word). The results showed (a) a consistent interaction between attentional instructions and repetition priming and (b) a qualitatively different ignored priming pattern as a function of prime duration: reduced positive priming (relative to the attend instruction) for prime exposures of 80 and 100 ms, and reliable negative priming for the shorter prime exposures of 20 and 50 ms. In addition (c), the differential priming pattern for attend and ignore trials was observed at a prime-target SOA of 800 ms (but not at a shorter 300-ms SOA) and only when instructions were presented before the prime word. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.     

Towards a functional neural systems model of developmental stuttering

This paper overviews recent developments in an ongoing program of brain imaging research on developmental stuttering that is being conducted at the University of Texas Health Science Center, San Antonio. This program has primarily used H₂¹⁵O PET imaging of different speaking tasks by right-handed adult male and female persistent stutterers, recovered stutterers and controls in order to isolate the neural regions that are functionally associated with stuttered speech. The principal findings have emerged from studies using condition contrasts and performance correlation techniques. The emerging findings from these studies are reviewed and referenced to a neural model of normal speech production recently proposed by Jürgens [Neurosci. Biobehav. Rev. 26 (2002) 235]. This paper will report (1) the reconfiguration of previous findings within the Jürgens Model; (2) preliminary findings of an investigation with late recovered stutterers; (3) an investigation of neural activations during a treatment procedure designed to produce a sustained improvement in fluency; and (4) an across-studies comparison that seeks to isolate neural regions within the Jürgens Model that are consistently associated with stuttering. Two regions appear to meet this criterion: right anterior insula (activated) and anterior middle and superior temporal gyri (deactivated) mainly in right hemisphere. The implications of these findings and the direction of future imaging investigations are discussed.

Educational objectives: The reader will learn about (1) recent uses of H₂¹⁵O PET imaging in stuttering research; (2) the use of a new neurological model of speech production in imaging research on stuttering; and (3) initial findings from PET imaging investigations of treated and recovered stutterers.     

Adrenocortical reactivity and social competence in seven year-olds

We examined temporal changes in salivary cortisol in response to a peer self-presentation task in a group of seven year-olds, some of whom scored high, average, and low on the Harter, 1983 Perceived Social Competence Scale. Salivary cortisol was measured pre-task, and 20 and 35 min post-task. We found a significant relation between individual differences in perceived social competence and salivary cortisol reactivity in response to the task. Children who perceived themselves as socially competent exhibited a significantly greater decrease in salivary cortisol from 20 to 35 min following the task compared with children who self-reported a relatively lower degree of social competence. We speculate on the meaning of salivary cortisol changes in childrens socio-emotional development.     

Evaluating Environmental Arrangement as Setting Events: Review and Implications for Measurement

Environmental arrangement alters the physical, social, or programmatic aspects of classrooms to increase task engagement, facilitate prosocial behaviors, and reduce or prevent the challenging behaviors of children and youth. Research shows specific arrangements can affect student engagement and deportment, but this literature is not well integrated theoretically or empirically with other effective behavior change tactics. This article proposes that some environmental arrangements may serve as setting events for child behavior change. Setting events and environmental arrangement were defined and critically outlined. A total of 43 physical environmental arrangement articles were reviewed as to the specific type of arrangement and research methodology. Several methodological problems (e.g., lack of measurement or control of antecedents, consequences, or environmental arrangements, manipulation of more than one environmental arrangement) precluded conclusions about the setting event function of environmental arrangements. Suggestions for future research on setting events and environmental arrangements are proposed.     

Case study: Reinforcement control of severe aggression exhibited by a child with autism in a family home

This clinical case study describes in-home treatment of severe aggression and tantrum behavior exhibited by an 11 -year-old child with autism, using methods of differential reinforcement comparable to those of a case study by Luiselli (1990). No significant reductions in problem conduct occurred when a parent implemented differential reinforcement of other behavior (DRO) in conjunction with publicly posted ‘good behavior rules,’ physical management training, and redirection to relaxation. Control was established when the child was reinforced for compliance with task demands in conjunction with extinction, implemented directly by professional support staff working in the home. Despite demonstrable parental consistency, systematic training, and fading of supports, results were not maintained at follow-up. The generality of differential reinforcement as a practical intervention for severe aggression in family homes is questioned.