Postural sway and joint kinematics during quiet standing are affected by lumbar extensor fatigue

The purpose of this study was to investigate changes in postural sway and strategy elicited by lumbar extensor muscle fatigue. Specifically, changes in center of mass (COM), center of pressure (COP), and joint kinematics during quiet standing were determined, as well as selected cross correlations between these variables that are indicative of movement strategy. Twelve healthy male participants stood quietly both before and after exercises that fatigued the lumbar extensors. Whole-body movement and ground reaction force data were recorded and used to calculate mean body posture and variability of COM, COP, and joint kinematics during quiet standing. Three main findings emerged. First, participants adopted a slight forward lean post-fatigue as evidenced by an anterior shift of the COM and COP. Second, post-fatigue increases in joint angle variability were observed at multiple joints including joints distal to the fatigued musculature. Despite these increases, anterior-posterior (AP) ankle angle correlated well with AP COM position, suggesting the body still behaved similar to an inverted pendulum. Third, global measures of sway based on COM and COP were not necessarily indicative of changes in individual joint kinematics. Thus, in trying to advance our understanding of how localized fatigue affects movement patterns and the postural control system, it appears that joint kinematics and/or multivariate measures of postural sway are necessary.     

Newborn Screening for Cystic Fibrosis: Parents’ Preferences Regarding Counseling At the Time of Infants’ Sweat Test

Newborn screening (NBS) protocols for cystic fibrosis (CF) are the first regional population-based programs to incorporate DNA analysis into their procedures. Research about these programs can inform policy and practice regarding how best to counsel families with abnormal NBS results. The grounded theory method guided interviews with 33 families whose infants had abnormal CF NBS results. A dimensional analysis of these interviews provided a theoretical framework describing parents’ preferences regarding counseling during their infant's sweat test appointment. This framework describes the contexts and characteristics of the two main dimensions of parents’ preferences: factual information and emotional support. Factual information included learning about the probability of a CF diagnosis, CF disease facts, sweat test procedure, and CF genetics. Social support consisted of offering parents a choice about the timing and amount of CF information, showing empathy for their distress, instilling hope, personalizing counseling, and providing hospitality. This framework also explains the consequences of counseling that matched versus mismatched parental preferences in these domains. Counseling that matched parents preferences reduced parents’ distress while mismatched counseling tended to increase parents’ worry about their infant.     

External correlates of the MMPI-2 content component scales in mental health inpatients

External correlates of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Content Component Scales were identified using an inpatient sample of 544 adults. The Brief Psychiatric Rating Scale (BPRS) and Symptom Checklist 90-Revised (SCL-90-R) produced correlates of the Content Component Scales, demonstrating external validity with clinician-rated and self-report scales. Relationships between MMPI-2 Content Component Scales and patient hospital chart variables were also examined. Results demonstrated cross-criterion validity in that most MMPI-2 Content Component Scales correlated with appropriate BPRS dimensions, SCL-90-R items, and other patient variables. Discriminant validity of the Content Component Scales was also demonstrated. In addition, the finding that similar patterns of correlates are produced when the component scales are correlated with a self-report measure, as well as clinician ratings and medical chart variables, provides converging lines of evidence supporting the construct validity of the Content Component Scales.     

The selective disruption of spatial working memory by eye movements

In the late 1970s/early 1980s, Baddeley and colleagues conducted a series of experiments investigating the role of eye movements in visual working memory. Although only described briefly in a book (Baddeley, 1986), these studies have influenced a remarkable number of empirical and theoretical developments in fields ranging from experimental psychology to human neuropsychology to nonhuman primate electrophysiology. This paper presents, in full detail, three critical studies from this series, together with a recently performed study that includes a level of eye movement measurement and control that was not available for the older studies. Together, the results demonstrate several facts about the sensitivity of visuospatial working memory to eye movements. First, it is eye movement control, not movement per se, that produces the disruptive effects. Second, these effects are limited to working memory for locations and do not generalize to visual working memory for shapes. Third, they can be isolated to the storage/maintenance components of working memory (e.g., to the delay period of the delayed-recognition task). These facts have important implications for models of visual working memory.     

The effects of behavioral history on response acquisition with immediate and delayed reinforcement

Effects of prior exposure to the experimental chamber with levers present or absent and variable-time (VT) 60-s water deliveries arranged during one, five, or no 1-hr sessions were examined in rats during a 6-hr response-acquisition session in which presses on one lever produced water delivery immediately or after a 15-s resetting delay, and presses on the other lever canceled scheduled water deliveries. Response acquisition was (a) slower to occur when water deliveries were delayed, (b) most consistent in groups that had received five VT sessions, and (c) impaired by the presence of levers only when there had been five VT sessions and water deliveries were delayed during the acquisition session.     

Variation in cue duration reveals top-down modulation of involuntary orienting to uninformative symbolic cues

This article reports three experiments in which the effects of cue duration on involuntary orienting to uninformative symbolic cues (arrows presented at fixation) were investigated. Experiment 1 showed that symbolic cues had less effect on involuntary orienting when they were presented for only 25 msec than when they were presented for 200 msec across a range of stimulus onset asynchronies. Experiment 2 suggested that the effect of cue duration on involuntary orienting was due primarily to top-down strategic factors, rather than to bottom-up stimulus factors, and Experiment 3 suggested that these strategic factors may involve differences in how the cue is processed. Altogether, the present findings are important because they emphasize the distinction between cue processing and the putative involuntary orienting that results from such processing in the symbolic-cuing paradigm. In so doing, the present results help resolve discrepant findings that have been reported across previous studies.     

Development of a school-wide behavior program in a public middle school: an illustration of deployment-focused intervention development, stage 1

School-wide behavior management systems can improve academic performance and behavior in middle schools, and they should have positive effects on students with ADHD. Unfortunately, evidence-based, school-wide behavior management systems have not been widely adopted because of problems with feasibility, acceptability, and sustainability. The Deployment-Focused Model of Intervention Development and Testing has been proposed as a promising method of bridging the gap between research and practice settings. A key aspect of the model is to involve the persons most likely to deliver the service (e.g., teachers) in the intervention development process from the very beginning. To illustrate this process, the authors describe the planning and implementation of a school-wide program designed to improve behavior in a public middle school.     

Investigator ratings of ADHD symptoms during a randomized, placebo-controlled trial of atomoxetine: a comparison of parents and teachers as informants

This study compared investigator ratings of ADHD symptoms based on interviews with parents and teachers during a doubleblind, placebo-controlled study of atomoxetine. Investigators completed the ADHD Rating Scale: Investigator (ADHDRS-I) based on separate semistructured interviews with the primary caretaker and teacher of the participant. Interviews were conducted at Visits 2 to 7 during a double-blind treatment protocol comparing atomoxetine (N= 10) and placebo (N= 6). Both parent and teacher-based ratings were sensitive to change in ADHD symptoms with atomoxetine treatment. Parent-based assessment differentiated significantly between treatment with atomoxetine and placebo, whereas teacher-based assessment was less sensitive to change. Parents and teachers showed good agreement on change in ADHDRS-I scores. Investigator ratings based on parent- and teacher-report were sensitive to change in symptoms of ADHD during treatment with atomoxetine. Despite good agreement between parent- and teacher-based ratings of symptom change, parent-based ADHD symptom ratings are more sensitive to symptom change.