David A. Wagstaff

The Information-Loss Model: A Mathematical Theory of Age-Related Cognitive Slowing

A model of cognitive slowing is proposed with the following assumption: Information is lost during processing, processing occurs in discrete steps with step duration inversely related to the amount of information currently available, and the effect of aging is to increase the proportion of information lost per step. This model correctly predicts a positively accelerated relation between latencies of older and younger adults and provides a unified account of the effects of task complexity, practice, speed-accuracy tradeoffs, and fluctuations in individual performance. Strong support for the thesis that cognitive slowing is global, and not localized in specific age-sensitive components, is provided by the fact that the model accurately predicts the latencies of older adults on the basis of those of younger adults, without regard to the nature of the task, across a latency range of nearly 2 orders of magnitude.

Outcomes of a randomized community-level HIV prevention intervention for women living in 18 low-income housing developments

OBJECTIVES Women in impoverished inner-city neighborhoods are at high risk for contracting HIV. A randomized, multisite community-level HIV prevention trial was undertaken with women living in 18 low-income housing developments in 5 US cities. METHODS Baseline and 12-month follow-up population risk characteristics were assessed by surveying 690 women at both time points. In the 9 intervention condition housing developments, a community-level intervention was undertaken that included HIV risk reduction workshops and community HIV prevention events implemented by women who were popular opinion leaders among their peers. RESULTS The proportion of women in the intervention developments who had any unprotected intercourse in the past 2 months declined from 50% to 37.6%, and the percentage of womens acts of intercourse protected by condoms increased from 30.2% to 47.2%. Among women exposed to intervention activities, the mean frequency of unprotected acts of intercourse in the past 2 months tended to be lower at follow-up (mean = 4.0) than at baseline (mean = 6.0). These changes were corroborated by changes in other risk indicators. CONCLUSIONS Community-level interventions that involve and engage women in neighborhood-based HIV prevention activities can bring about reductions in high-risk sexual behaviors.

Culturally Grounded Substance Use Prevention: An Evaluation of the keepin' it R.E.A.L. Curriculum

This paper reports on the evaluation of a culturally grounded prevention intervention targeting substance use among urban middle-school students. The curriculum consists of 10 lessons promoting antidrug norms and teaching resistance and other social skills, reinforced by booster activities and a media campaign. Three versions were delivered: Mexican American, combined African American and European American, and Multicultural. Thirty-five middle schools were randomly assigned to 1 of the 3 versions or the control. Students completed baseline and follow-up questionnaires over a 2-year period (total 6,035 respondents). Analyses utilizing a generalized estimating equations approach assessed the overall effectiveness of cultural grounding and the cultural matching hypothesis. Support was found for the interventions overall effectiveness, with statistically significant effects on gateway drug use as well as norms, attitudes, and resistance strategies but with little support for the cultural matching hypothesis. Specific contrasts found the Mexican American and Multicultural versions impacted the most outcomes.

Is it “Sex”?: College students' interpretations of sexual behavior terminology

Little is known regarding how respondents interpret terms that are commonly used in sexual behavior surveys. The present study assessed the impact of four factors on respondents’ judgments of whether the hypothetical actors “Jim” and “Susie “ would consider a particular behavior that they had engaged in to be “sex.” The four factors were respondents gender, actors gender, type of act (vaginal, anal, or oral intercourse), and who achieved orgasm (neither, Jim only, Susie only, or both). Two hundred twenty‐three undergraduates (22.2 ± 2.2 years; 65% female) were asked to read 16 scenarios featuring Jim and Susie and to judge whether each actor would consider the described behavior to be sex. Results indicated that vaginal and anal intercourse were considered sex under most circumstances. Whether oral intercourse was labeled as sex depended on the gender and viewpoint of the actor, and whether orgasm occurred. Findings suggest that items in sexual behavior surveys need to be clearly delineated to avoid subjective interpretations by respondents.

Acculturation Status and Substance Use Prevention with Mexican and Mexican-American Youth

SUMMARY This study examined whether language preference, as an indicator of acculturation, moderated the effects of a culturally grounded substance use prevention intervention for Mexican and Mexican American middle school students (N = 2,146) in Phoenix, Arizona. The main hypothesis was that levels of program effectiveness would vary based on the language preference of the students and the specific culturally grounded version of the intervention they were assigned. Findings show that matching language preference to particular versions of the intervention did not influence substance use related program outcomes, but that overall program effects (intervention versus control) did vary by language preference. English-language dominant participants, the most at risk sub-group, responded more positively to the intervention, while Spanish dominant, who had low substance use rates at baseline, and bilingual participants did not demonstrate significant differences between the intervention and control groups. Implications for school social work prevention interventions and prevention science in general, are discussed.

The Impact of a Culturally Appropriate STD/AIDS Education Intervention on Black Male Adolescents’ Sexual and Condom Use Behavior

A culturally appropriate, theoretically based videotape was developed to promote condom use among African American males, ages 15 to 19, attending a municipal sexually transmitted disease (STD) clinic. The video-tape’s impacts were compared to those achieved by an African American health educator who delivered the same messages during a face-to-face session and by standard care. Data were obtained on participants’ (N = 562) condom use knowledge, self-efficacy, and intentions; sexual and condom use behaviors; and perceived risk of infection. At posttest, “videotape” and “health educator” participants demonstrated greater condom use knowledge; “health educator” participants indicated greater self-efficacy and stronger condom use intentions with steady partners. At 6 months, participants in all conditions reported more partners and acts of vaginal intercourse (past month); however, they were more likely to report consistent condom use with steady partners (18% vs. 53%) and casual partners (26% vs. 50%). Perceived risk of infection was lower at the posttest and declined during the study period.

Sexual decision making by inner city black adolescent males: A focus group study

This research was designed to illuminate the cognitive and emotional bases of the sexual decisions made by young Black men. It was guided by the assumption that the Black males understanding and expression of his sexuality reflects a socially constructed interpretation of who he is. Specifically, we believe that sexual decision making is guided by sexual scripts. Focus groups were conducted with 27 Black young men ages 15 to 19. Analyses of the transcripts of these discussions identified four sets of beliefs that are related to sexual decisions: what it means to be a man, good and bad things about sexual intimacy, beliefs about condoms, and beliefs about AIDS. We also identified seven concerns in our analyses: (a) good girls, bad girls; (b) asking for sex; (c) “running the game” (d) being “hooked up” (e) conflicts with other men; (f) the relation between sex and love; and (g) male roles and fatherhood. Quotations from the participants illustrate each of these concerns. The participants were asked at the ...

Model-Based Evaluation of Hiv Prevention Interventions

The ultimate goal of HIV prevention interventions is to reduce the spread of HIV; however, the effectiveness of these programs is seldom assessed directly. Although direct measurement of an interventions impact via HIV seroincidence monitoring is usually unfeasible, mathematical models can be used to estimate the number of infections averted by the intervention. This article describes three model-based summary measures of sexually transmitted HIV risk and discusses their relevance to HIV program evaluation m general and economic efficiency analyses in particular. The calculation of these measures is demonstrated with an illustrative application to previously published data from an HIV prevention intervention for gay men.

Behavioral profiles associated with auditory processing disorder and specific language impairment

PURPOSE To describe and compare behavioral profiles associated with auditory processing disorder (APD) and specific language impairment (SLI) in school-age children. METHOD The participants in this cross-sectional observational study were 64 children (mean age 10.1 years) recruited through clinician referrals. Thirty-five participants had a clinical diagnosis of APD and 29 were receiving services for language impairment. Participants completed 18 behavioral measures of spoken language, auditory processing, reading, memory, and motor speed. Responses were used to classify children as affected/not affected with APD, and affected/not affected with SLI. Comparisons were made between children with and without an APD diagnosis, and between children assigned to the APD/not APD and SLI/not SLI groups. Agreement between clinical status and test-based classifications is also reported. RESULTS There were no group mean differences between children with and without a clinical diagnosis of APD. Group mean differences on Cube Design and reading fluency were observed for children classified as APD/not APD; and group mean differences on nonword repetition, spatial working memory, and two auditory processing tests were observed for children classified as SLI/not SLI. CONCLUSIONS The behavioral profiles of children with APD and SLI were very similar. Although group mean differences were found, they were difficult to interpret in terms of current theories. LEARNING OUTCOMES The reader will be able to: (1) describe similarities and differences found between children with SLI and children with APD and (2) discuss assessment problems posed by overlapping behavioral characteristics of SLI and APD.

Diagnostic criteria patterns of U.S. children with Metabolic Syndrome: NHANES 1999–2002

BackgroundAs childhood obesity increases in the U.S., the Metabolic Syndrome (MS) can be assumed to be increasing in the pediatric population as well. To date, there is lack of information on the most prevalent risk factors of MS in children and the patterns of risk factors present in children met the criteria for MS.MethodsAnthropometric and medical data of children 2–18 years old of a nationally representative data set (NHANES 1999–2002) were obtained and the diagnostic criteria of Cook et al. employed to determine MS prevalence. Three samples were examined: a) Children 2–18 years old with non-missing data on at least three of the five diagnostic criteria but missing blood glucose data (n = 5,172), b) a subsample of 12–18 year olds also providing fasting glucose data but who were not overweight or obese using the International Obesity Task Force (IOTF) standards (n = 1,064), and c) 12–18 year olds with blood glucose data who were overweight or obese (n = 641).ResultsDisease prevalence estimates were 2%, 0.7%, and 23% in the three populations. More than 10% of the children providing fasting blood levels had hyperglycemia. 2% of the overweight or obese 12–18 year olds with fasting blood glucose data met all five diagnostic criteria for MS. In all groups, elevated total triglycerides but low high density lipoprotein (HDL) level affected a large proportion of the population.ConclusionResults indicate a reason for concern, since the prevalence of MS risk factors in children was high. Dyslipidemia (concurrent high total triglyceride levels and low HDL levels) were prevalent in large portions of the population, even in the non-overweight. Thus, chronic disease prevention efforts in the pediatric population should not only encourage healthy body weight but also include dietary recommendations to consume diets moderately low in fat with emphasis on polyunsaturated and monounsaturated fats within recommended ratios of omega-6 and omega-3 fatty acids.