Faculty Bibliography

Standing and walking generate information about friction underfoot. Five experiments examined whether walkers use such perceptual information for prospective control of locomotion. In particular, do walkers integrate information about friction underfoot with visual cues for sloping ground ahead to make adaptive locomotor decisions? Participants stood on low-, medium-, and high-friction surfaces on a flat platform and made perceptual judgments for possibilities for locomotion over upcoming slopes. Perceptual judgments did not match locomotor abilities: Participants tended to overestimate their abilities on low-friction slopes and underestimate on high-friction slopes (Experiments 1-4). Accuracy improved only for judgments made while participants were in direct contact with the slope (Experiment 5), highlighting the difficulty of incorporating information about friction underfoot into a plan for future actions.

OBJECTIVE: To examine symptomatology and mental health service use following students' contact with a large urban school district's suicide prevention program. METHOD: In 2001 school district staff conducted telephone interviews with 95 randomly selected parents approximately 5 months following their child's contact with the district's suicide prevention program, a School Gatekeeper Training model. Parents provided information regarding service use, their child's depressive symptoms (using the Diagnostic Interview Schedule for Children Predictive Scale, Depression module), and their perceptions of their child's need for services. Information about the crisis intervention was abstracted from a standardized assessment form. RESULTS: More than two thirds of students received school or community mental health services following contact with the suicide prevention program. Depressive symptoms, but not past year suicide attempt, predicted community mental health service use. Latino students had lower rates of community mental health service use than non-Latinos. School-based service use did not differ by student characteristics including race/ethnicity. CONCLUSIONS: Most students identified by a school-based suicide prevention program received follow-up care, although Latinos were less likely to access services outside the school. School-based mental health services may be an important way in which underserved populations at risk of suicide can receive care.

INTRODUCTION: Evidence suggests that mothers are negative and critical when talking about their children with behaviour problems. However the association with specific types of behaviour problems and the influence of both child and adult psychopathology on these relationships require further clarification. METHODS: Speech samples were gathered from mothers of 100 school-aged boys and coded using standard Expressed Emotion (EE) categories. Levels of maternal and child psychopathology were ascertained using standardised questionnaires completed by the mother. RESULTS: There were significant and positive correlations between criticism and child ADHD, conduct and emotional symptoms respectively. There were also significant and negative correlations between EOI and child ADHD and conduct problems. CONCLUSIONS: The findings of the current study suggest that when considered together EE is driven more by the child rather than by maternal characteristics and these effects are specific to conduct and emotional problems. The implications of the findings are discussed

BACKGROUND: Attaining a developmentally sensitive nosology for preschool disruptive behavior requires characterization of the features that distinguish it from the normative misbehavior of this developmental period. We hypothesize that quality of behavior and its pervasiveness across contexts are critical dimensions for clinical discrimination in young children and propose that structured diagnostic observation provides a systematic method for their identification. We use the Disruptive Behavior Diagnostic Observation Schedule (DB-DOS) to examine whether: (a) observed quality and pervasiveness of behavior distinguishes preschoolers with clinically concerning disruptive behavior from typically developing preschoolers, and (b) observed pattern of clinically salient behavior predicts impairment above and beyond maternal report of behavioral frequency. METHODS: Participants are a behaviorally heterogeneous sample of preschoolers (N = 327). Diagnostic methods developed for clinical assessment of preschoolers were used to classify children as (a) Non-Disruptive, (b) Sub-Clinical, or (c) Disruptive. Child behavior was coded based on interactions with parent and examiner during the DB-DOS. RESULTS: Quality and pervasiveness of observed behaviors during the DB-DOS significantly distinguished the three behavioral groups. Discriminative utility varied depending on the comparison. With few exceptions, clinically concerning patterns on the DB-DOS added significant incremental utility in predicting impairment. CONCLUSIONS: Observed patterns of clinically salient behavior show promise for advancing developmentally-informed characterization of disruptive behavior within the preschool period

Perceived social-evaluative threat triggers the hypothalamic-pituitary adrenal (HPA) axis, resulting in cortisol release. The current study examined the effects of varying the levels of social-evaluative threat on the stress response. Sixty healthy men (mean age + 23.17 +/- 3.89 years) underwent a public speaking task. Four conditions were established on the basis of panel location (inside or outside the room) and number of panelists (one or two). It was hypothesized that these variations affect salivary cortisol and physiological responses in a gradient manner. The task elicited significant cortisol and blood pressure changes for all conditions, but no difference between the groups was found, suggesting that all conditions were equally stressful. Study conclusions were that, for men, the visual presence of a panel is not necessary to elicit a cortisol response. Furthermore, increasing the number of judges does not increase the intensity of the stress response in a gradual manner, but rather seems to follow a threshold pattern. Future studies should include women and try to define the possible threshold to activate the HPA axis

In 118 children followed from age 2 to 5 (59 with autism, 24 with PDD-NOS and 35 with non-spectrum developmental disabilities), age 2 and age 3 scores of non-verbal ability, receptive communication, expressive communication and socialization were compared as predictors of receptive and expressive language at age 5. Non-verbal cognitive ability at age 2 was generally the strongest predictor of age 5 language, while at age 3 communication scores were a stronger predictor of age 5 language for children with autism. Early joint attention as well as vocal and motor imitation skills were more impaired in children who did not develop language by age 5 (but had relatively strong non-verbal cognitive skills) than in children who did develop language by 5

This study examined change prospectively in autism symptoms and maladaptive behaviors during a 4.5 year period in 241 adolescents and adults with an autism spectrum disorder who were 10-52 years old (mean = 22.0) when the study began. Although many individuals' symptoms remained stable, a greater proportion of the sample experienced declines than increases in their level of autism symptoms and maladaptive behaviors, and there were significant improvements in mean levels of symptoms. Individuals with mental retardation had more autism symptoms and maladaptive behaviors than those without mental retardation, and they improved less over time. Compared to adolescents, older sample members (31 and older) had fewer maladaptive behaviors and experienced more improvement in these behaviors over time

Regression of a scalar response on signal predictors, such as near-infrared (NIR) spectra of chemical samples, presents a major challenge when, as is typically the case, the dimension of the signals far exceeds their number. Most solutions to this problem reduce the dimension of the predictors either by regressing on components [e.g., principal component regression (PCR) and partial least squares (PLS)l or by smoothing methods, which restrict the coefficient function to the span of a spline basis. This article introduces functional versions of PCR and PLS, which combine both of the foregoing dimension-reduction approaches. Two versions of functional PCR are developed, both using B-splines and roughness penalties. The regularized-components version applies such a penalty to the construction of the principal components (i.e., it uses functional principal components), whereas the regularized-regression version incorporates a penalty in the regression. For the latter form of functional PCR, the penalty parameter may be selected by generalized cross-validation, restricted maximum likelihood (REML), or a minimum mean integrated squared error criterion. Proceeding similarly, we develop two versions of functional PLS. Asymptotic convergence properties of regularized-regression functional PCR are demonstrated. A simulation study and split-sample validation with several NIR spectroscopy data sets indicate that functional PCR and functional PLS, especially the regularized-regression versions with REML, offer advantages over existing methods in terms of both estimation of the coefficient function and prediction of future observations. $$:

Our goal was to examine the relationship between early life trauma and the development of visceral hypersensitivity in later life in irritable bowel syndrome (IBS). Rat pups underwent neonatal conditioning: (i) paired odour-shock, where odour is a predictable shock signal, (ii) unpaired odour-shock, where odour is an unpredictable shock signal or (iii) control odour-only with odour presentations and handling without shock. At maturity, colorectal sensitivity was measured as a visceromotor behavioural response. In adulthood, colorectal distension (CRD) induced a pressure-dependent increase in the number of abdominal muscle contractions all three experimental groups. However, compared to animals that had received control odour-only presentations in infancy, there was an attenuated response to CRD in animals previously exposed to neonatal predictable shock pups and an exaggerated response in the animals previously exposed to neonatal unpredictable shock. Adult responses to CRD were altered by infant experience with shock trauma. However, depending on the context of that early life trauma, there are major differences between the long-term effects of that early life trauma on colonic sensitivity compared to controls. These results strengthen the link between early life trauma and adult IBS, and suggest that unpredictable trauma is a critical factor for later life disorders.