Psychometric properties of inhibitory control measures among youth with Down syndrome.

BACKGROUND: Inhibitory control measures have been commonly used when assessing individuals with Down syndrome. However, minimal attention has been devoted to evaluating the appropriateness of specific assessments for use in this population, potentially leading to erroneous conclusions. This study aimed to examine the psychometric properties of measures of inhibitory control among youth with Down syndrome. We sought to examine the feasibility, presence of floor or practice effects, test-retest reliability, convergent validity and correlations with broader developmental domains of a set of inhibitory control tasks. METHODS: A sample of 97 youth with Down syndrome aged 6 to 17 years old participated in verbal and visuospatial tasks of inhibitory control including the Cat/dog Stroop, Neuropsychological Assessment Second Edition (NEPSY-II) Statue, National Institutes of Health (NIH) Toolbox Cognition Battery (TCB) Flanker, Leiter-3 Attention Sustained, and the Test of Attentional Performance for Children (KiTAP) Go/No-go and Distractibility subtests. Youth also completed standardised assessments of cognition and language, and caregivers completed rating scales. Psychometric properties on the tasks of inhibitory control were evaluated against a priori criteria. RESULTS: Apart from demonstrating negligible practice effects, adequate psychometric properties were not observed for any inhibitory control measure within the current sample's age range. One task with low working memory demands (NEPSY-II Statue) generally had better psychometric properties than the other tasks assessed. Subgroups of participants with an IQ greater than 30 and age more than 8 years were shown to be more likely to be able to complete the inhibition tasks. CONCLUSIONS: Findings suggest better feasibility for analogue tasks rather than computerised assessments of inhibitory control. Given the weak psychometrics of several common measures, future studies are required to evaluate other inhibitory control measures, specifically those with reduced working memory demands for youth with Down syndrome. Recommendations for use of the inhibitory control tasks among youth with Down syndrome are provided.

Evaluating working memory outcome measures for children with Down syndrome.

BACKGROUND: There is a critical need for the psychometric evaluation of outcome measures to be used in clinical trials targeting cognition in Down syndrome (DS). This study examines a specific cognitive skill that is of particular importance in DS, working memory, and the psychometric properties of a set of standardised measurements to assess working memory in individuals with DS. METHODS: Ninety children and adolescents ages 6 to 18 years old with DS were assessed on a selection of verbal and visuospatial working memory subtests of standardised clinical assessments at two time points to examine feasibility, distributional qualities, test-retest reliability and convergent validity against a priori criteria. Caregivers also completed an adaptive behaviour questionnaire to address working memory subtests' associations with broader developmental functioning. RESULTS: The Stanford Binet-5 Verbal Working Memory, Differential Ability Scales-2 Recognition of Pictures, Stanford Binet-5 Nonverbal Working Memory and Wechsler Intelligence Scale for Children-5 Picture Span measures met the most psychometric criteria overall across the full age and IQ range of the study. Although Differential Ability Scales-2 Recall of Sequential Order and Differential Ability Scales-2 Recall of Digits Backward met the fewest a priori criteria, follow-up analyses suggested greater feasibility in specific age and IQ ranges. CONCLUSIONS: Several working memory measures appear to be psychometrically sound and appropriate for use in clinical trials for children with DS, especially when focusing on raw scores. However, floor effects on standard scores and feasibility of some measures were problematic. Guidelines for use of the working memory subtests with this population are provided.

Network-based Responses to the Psychomotor Vigilance Task during Lapses in Adolescents after Short and Extended Sleep.

Neuroimaging studies of the Psychomotor Vigilance Task (PVT) have revealed brain regions involved in attention lapses in sleep-deprived and well-rested adults. Those studies have focused on individual brain regions, rather than integrated brain networks, and have overlooked adolescence, a period of ongoing brain development and endemic short sleep. This study used functional MRI (fMRI) and a contemporary analytic approach to assess time-resolved peri-stimulus response of key brain networks when adolescents complete the PVT, and test for differences across attentive versus inattentive periods and after short sleep versus well-rested states. Healthy 14-17-year-olds underwent a within-subjects randomized protocol including 5-night spans of extended versus short sleep. PVT was performed during fMRI the morning after each sleep condition. Event-related independent component analysis (eICA) identified coactivating functional networks and corresponding time courses. Analysis of salient time course characteristics tested the effects of sleep condition, lapses, and their interaction. Seven eICA networks were identified supporting attention, executive control, motor, visual, and default-mode functions. Attention lapses, after either sleep manipulation, were accompanied by broadly increased response magnitudes post-stimulus and delayed peak responses in some networks. Well-circumscribed networks respond during the PVT in adolescents, with timing and intensity impacted by attentional lapses regardless of experimentally shortened or extended sleep.

Links between sleep and daytime behaviour problems in children with Down syndrome.

BACKGROUND: In the general population, sleep problems have an impact on daytime performance. Despite sleep problems being common among children with Down syndrome, the impact of sleep problems on daytime behaviours in school-age children with Down syndrome is an understudied topic. Our study examined the relationship between parent-reported and actigraphy-measured sleep duration and sleep quality with parent and teacher reports of daytime behaviour problems among school-age children with Down syndrome. METHOD: Thirty school-age children with Down syndrome wore an actigraph watch for a week at home at night. Their parent completed ratings of the child's sleep during that same week. Their parent and teacher completed a battery of measures to assess daytime behaviour. RESULTS: Parent reports of restless sleep behaviours on the Children's Sleep Habits Questionnaire, but not actigraph-measured sleep efficiency, was predictive of parent and teacher behavioural concerns on the Nisonger Child Behaviour Rating Form and the Vanderbilt ADHD Rating Scales. Actigraph-measured sleep period and parent-reported sleep duration on the Children's Sleep Habits Questionnaire was predictive of daytime parent-reported inattention. Actigraph-measured sleep period was predictive of parent-reported hyperactivity/impulsivity. CONCLUSION: The study findings suggest that sleep problems have complex relationships to both parent-reported and teacher-reported daytime behaviour concerns in children with Down syndrome. These findings have implications for understanding the factors impacting behavioural concerns and their treatment in school-age children with Down syndrome.

The relationship between CVLT-C process scores and measures of executive functioning: lack of support among community-dwelling adolescents.

In an effort to characterize how a child goes about learning and recalling information, the developers of the California Verbal Learning Test for Children (CVLT-C) provided normative data related to both learning outcome and learning process. The present study examined the assertion that CVLT-C process indices relate to executive functioning in a sample of community-dwelling adolescents. Contrary to predictions, measures of executive functioning typically correlated poorly with measures of learning process, despite displaying significant correlations with measures of learning outcome. Although further research is recommended, these findings do not support the clinical interpretation of CVLT-C process indices as reflections of executive functioning.

The third factor of the WISC-III: it's (probably) not freedom from distractibility.

OBJECTIVE: This study examined the ecological validity, construct validity, and diagnostic utility of the third factor of the WISC-III, heuristically labeled "Freedom From Distractibility" (FFD). METHOD: A sample of 200 children, aged 6 to 11 years, with attention-deficit hyperactivity disorder (ADHD) completed the WISC-III, the Wide Range Achievement Test-Revised, and the Test of Variables of Attention. Objective parent and teacher report measures of attention and hyperactivity were completed. RESULTS: Mean FFD scores were significantly lower than other WISC-III factor scores. The diagnostic utility of FFD is limited, however, as the majority of these children did not show a significant relative weakness on this index. Correlational analyses failed to support the concurrent, ecological, or construct validity of the FFD. FFD scores were not correlated with a measure of sustained visual attention. Findings suggest that among children with ADHD, a low FFD score may be associated with the presence of a learning disability or poor academic performance. This finding was maintained after level of general intelligence was statistically controlled. CONCLUSIONS: Clinicians and researchers should not view FFD as a reliable or valid index of attention or as a diagnostic screening measure for identifying children with ADHD.

Normative and psychometric data on the body image assessment--revised.

After falling into disfavor in the early 1990s, the construct of body image, as measured by body-size estimation (BSE) techniques, has been the focus of increasing interest in the eating disorder literature because of recent theoretical, empirical, and methodological advances. However, no published BSE measure to date has been shown to be psychometrically sound, well normed, inexpensive, and straightforward. This article provides normative and psychometric data for an adapted silhouette BSE measure. Comprehensive normative data are presented on college women's cognitively and affectively based body-size estimates, as well as their desired body size and related discrepancy indexes (cognitive vs. desired, affective vs. desired, affective vs. cognitive). Preliminary data indicate that indexes from the new measure are moderately reliable over time, consistent with their theoretical link to fluctuations in body-related attitudes. Data also support the convergent validity of the measures. Affectively based BSE, alone or as part of a discrepancy measure with desired body size, was most strongly related to measures of eating pathology, body focus, body dissatisfaction, and depressed affect.

Is body focus restricted to self-evaluation? Body focus in the evaluation of self and others.

OBJECTIVE: Clinicians have suggested that the core pathology of the eating disorders is an extreme body focus in self-evaluation. This study investigated whether women who focus on their own bodies place a similar focus on body shape when evaluating others and expect others to have a strong body focus in their self-evaluations. METHOD: Eighty-four undergraduate women completed the Eating Attitudes Test (EAT-26), which largely measures body focus in self-evaluation. Each was also shown a series of photographs of women and asked what aspects of the photos they first noticed and how the depicted women felt about themselves. Finally, each responded to scenarios in which they or a hypothetical woman overate or dieted. RESULTS: High EAT-26 scores were associated with an elevated number of "fat" or "thin" feelings attributed to women in the slides and a marginally greater number of body-related observations made about the slides. High EAT-26 scores were also associated with inferred negative feelings of others after overeating and positive feelings of others after dieting. In fact, the relationships between EAT-26 scores and feelings in response to hypothetical overeating and dieting situations were no stronger when applied to the self than when applied to others. However, when presented with a situation in which they overate, participants showed stronger relationships between their EAT-26 scores and their expected weight change and dieting behavior than they predicted would occur for others after an identical period of overeating. DISCUSSION: Extrapolating findings to a clinical population, women with eating disorders may focus on others' body shapes as well as their own. These women may also expect others to be as emotionally invested in their own body shapes as they are themselves, but may not expect others to be as prone to gain weight or to diet as strictly as they do. Treatment for this somewhat recalcitrant belief system is discussed, as are directions for future research.

Low-end specificity of four depression measures: findings and suggestions for the research use of depression tests.

Past research has found that very low scorers on the Beck Depression Inventory (BDI) tend to respond in a "fake-good" manner on the Minnesota Multiphasic Personality Inventory (MMPI) validity scales. This findings was interpreted as evidence of poor "low-end specificity." This study replicated and extended this work by evaluating the low-end specificity of four popular depression measures. The evidence of problems with low-end specificity was strong for the BDI and marginal for the Profile of Mood States depression subscale. Interestingly, MMPI scores in the "normal" range were associated with "fake-good" responding, whereas very low and high scores were not. There was no evidence of an association between fake-good responding and scores on Exner's Depression Index for the Rorschach. Implications of these findings and guidelines for dealing with problems with low-end specificity in research are discussed.

The attention to body shape scale: a new measure of body focus.

An abnormal degree of attention to one's body shape has been implicated in the development and maintenance of eating pathology. This article reports on three preliminary reliability and validity studies of the Attention to Body Shape Scale (ABS). Although brief, the ABS was found to be internally consistent and relatively stable over 2 weeks for both women and men. As expected, women were more body-focused on the ABS than were men. Preliminary validation studies on college women had encouraging results. Lending evidence of convergent validity, the ABS correlated with measures of eating pathology and dietary restraint. Moreover, although the ABS correlated with a measure of general-appearance orientation, regression analyses showed that the former was more closely linked than the latter to eating pathology. As evidence of discriminant validity, the ABS failed to correlate with dysphoria, body weight, or the tendency to eat in response to emotional or environmental pressures. As predicted by theory, high scores on the ABS were associated with body-image distortion. However, contrary to predictions, the ABS failed to moderate the impact of induced anxiety on body image on two of three measures. The implications of these findings and suggestions for future work are discussed.

Identification of "binge-prone" women: an experimentally and psychometrically validated cluster analysis in a college population.

This study investigated the escape model of binge eating through a cluster analysis using standardized measures. A sample of 126 undergraduate women underwent a manipulation of their level of cognition and were asked to "taste-test" several flavors of ice cream. Questionnaire data from these women were entered into a cluster analysis. Two groups emerged: women in the "binge-prone" group were significantly more depressed, had lower self-esteem, had more chaotic and extreme eating patterns, and were more self-conscious than those in the control group. In validation work, binge-prone women were shown to report elevated levels of bulimic symptomatology and, when in the presence of a food they enjoyed, to respond to increases in level of cognition by eating more. These results were consistent with some, but not all, of the components of the escape model.

Bulimia nervosa and depression: a theoretical and clinical appraisal in light of the binge-purge cycle.

This review seeks to familiarize clinicians with several major theoretical perspectives on the relationship between bulimia nervosa and depression. It begins by clarifying the affective changes which occur within the binge-purge cycle. Six hypotheses relating negative affect to bulimia nervosa are then reviewed in light of these changes, with their strengths, weaknesses and clinical implications clearly outlined. The author concludes that, although none of these perspectives has received universal support, recent hypotheses which focus upon specific portions of the binge-purge cycle are best suited to integration. These include the restraint, escape and hopelessness hypotheses. An integrative model is proposed to account for data across the binge-purge cycle, to assist in understanding the maintenance of bulimia nervosa, and to guide clinical intervention.