Using data augmentation to obtain standard errors and conduct hypothesis tests in latent class and latent transition analysis

Latent class analysis (LCA) provides a means of identifying a mixture of subgroups in a population measured by multiple categorical indicators. Latent transition analysis (LTA) is a type of LCA that facilitates addressing research questions concerning stage-sequential change over time in longitudinal data. Both approaches have been used with increasing frequency in the social sciences. The objective of this article is to illustrate data augmentation (DA), a Markov chain Monte Carlo procedure that can be used to obtain parameter estimates and standard errors for LCA and LTA models. By use of DA it is possible to construct hypothesis tests concerning not only standard model parameters but also combinations of parameters, affording tremendous flexibility. DA is demonstrated with an example involving tests of ethnic differences, gender differences, and an Ethnicity x Gender interaction in the development of adolescent problem behavior.     

Extending neuropsychological assessments into the primary mental ability space

A battery of 17 neuropsychological tests (including the CERAD battery) and 17 psychometric ability tests were administered to a sample of 499 participants of the Seattle Longitudinal study who had been given the psychometric ability tests seven and 14 years earlier. The neuropsychological tests were projected into a 5-factor psychometric ability space by means of extension analysis. The concurrent regressions of the neuropsychology tests on the psychometric ability tests were then used to estimate neuropsychology test scores from the psychometric ability tests administered in 1984, 1991 and 1998. Neuropsychologists then rated the study participants as either normal, suspect or cognitively impaired in 1998. Changes in estimated test scores were computed over seven and fourteen years. Significant odds ratios between normal and cognitively impaired groups were found for all neuropsychological tests over the proximal period and for most tests over the 14-year period. Similar findings occurred for the odds ratios between the normal and suspect groups for the most proximal 7-year changes.     

Amygdala activation to sad pictures during high-field (4 tesla) functional magnetic resonance imaging

Fear-related processing in the amygdala has been well documented, but its role in signaling other emotions remains controversial. The authors recovered signal loss in the amygdala at high-field strength using an inward spiral pulse sequence and probed its response to pictures varying in their degree of portrayed sadness. These pictures were presented as intermittent task-irrelevant distractors during a concurrent visual oddball task. Relative to neutral distractors, sad distractors elicited greater activation along ventral brain regions, including the amygdala, fusiform gyrus, and inferior frontal gyrus. In contrast, oddball targets engaged dorsal sectors of frontal, parietal, and cingulate cortices. The amygdala's role in emotional evaluation thus extends to images of grief and despair as well as to those depicting violence and threat.     

Relationships between physical activity and motor skills in middle school children

The purpose of this study was to examine the relationships between physical activity measured as pedometer steps and performance on three motor skill tests. A secondary purpose was to determine if middle school children are meeting the recommendation for the number of daily steps. A sample (n =217) of 6th, 7th and 8th grade students participated. Each subject wore a Digi-Walker pedometer for three consecutive days. Subjects additionally recorded their pedometer steps in two 45 min.-physical education classes. There were strong significant correlations between daily steps taken by boys and girls, pedometer steps during physical education class and the AAHPERD Passing Test and the Bass Stick Balance. Similar correlations were weaker for the Side-Step Agility Test. Multivariate analysis of variance was utilized to examine variability of the three skills test by sex and year in school. Differences between students in Grades 7 and 8 on the AAHPERD Passing Test were significant. In addition, significant differences between daily pedometer steps and steps during physical education between Grades 6 and 7 were observed. Boys and girls had similar means on the AAHPERD Passing Test and Bass Stick Balance Test, but not on the Side-Step Agility Test. Scores on the three movement skills tested in this study were not strongly related to physical activity of the entire sample. Steps taken by middle school children appear not to be related to these measures of motor skills.     

Career benefits associated with mentoring for protégeé: a meta-analysis

Meta-analysis was used to review and synthesize existing empirical research concerning the career benefits associated with mentoring for the protégé. Both objective (e.g., compensation) and subjective (e.g., career satisfaction) career outcomes were examined. Comparisons of mentored versus nonmemored groups were included, along with relationships between mentoring provided and outcomes. The findings were generally supportive of the benefits associated with mentoring, but effect sizes associated with objective outcomes were small. There was also some indication that the outcomes studied differed in the magnitude of their relationship with the type of mentoring provided (i.e. career or psychosocial).     

Numerical stroop effect

2 male and 2 female students from an undergraduate class in experimental psychology were participants in a numerical Stroop effect experiment. Mean age for the students was 19.5 yr., with a SD of 2.4. The Stroop effect was investigated with a numerical, as opposed to a color, task. The four conditions were Symbols (-, + + +, ===, ::, :::), versus Alphabetic Characters (C, AAA, DD, BBB, DDD), versus Matched Digits and Number of Digits (1, 4444, 333, 22, 4444), versus Mismatched Digits and Number of Digits (2, 1111, 444, 33, 3333). Participants took longer to count Mismatched Digits than Symbols or Alphabetic Characters (analogous to the color Stroop effect). Participants took longer to read Mismatched Digits than Alphabetic Characters (analogous to the color reverse Stroop effect). Participants took less time to read or count Matched Digits than Alphabetic Characters (facilitation effect).     

Self-control in rhesus macaques (Macaca mulatta): controlling for differential stimulus exposure

Previous research on self-control using macaques (Macaca fascicularis) showed these animals have a strong bias for a delayed, larger reinforcer (Self-control) over an immediate, smaller reinforcer (Impulsive). Typical studies of self-control have used a discrete trials methodology with a secondary discriminative stimulus during the delay periods. This results in a greater exposure to the stimulus representing the self-controlled option and may account for some of the early exclusive preference for self-control observed. The present experiment examined self-control bias in three rhesus macaques (Macaca mulatta) while controlling for differential durations of stimulus exposure. Subjects were presented stimuli via a computer monitor and made choices by touching the stimulus at which point both stimuli were removed for the delay periods. All three subjects displayed a nearly exclusive bias for the delayed, larger reinforcer self-control). These results are consistent with previous studies, despite the variations in methodology and species.     

Adult attachment and patterns of extradyadic involvement

Relationships between patterns of extradyadic involvement (EDI) and adult attachment were examined separately with undergraduates and community adults reporting prior EDI. Those with fearful or preoccupied styles reported more intimacy motivations for EDI, and undergraduates with these styles also reported more self-esteem motivations. Conversely, those with a dismissive style reported more autonomy motivations for EDI. Those with a fearful attachment style reported ambivalence about intimacy in the EDI. Fearful and preoccupied undergraduates and community males reported a more obsessive extradyadic relationship. However, dismissive individuals did not report more casual EDI. Gender effects also emerged, with females reporting more intimacy motivations than males, and undergraduate males reporting more casual EDI than undergraduate females. In the undergraduate sample, dismissive males had the most extradyadic partners over the prior 2 years relative to all other groups, and preoccupied females reported more partners than secure females. Clinical implications of these findings are discussed.     

A comparative study of values and attitudes of inner-city and middle-class postpartum women

This study compared postpartum women from the inner city (n = 94) and postpartum women from the urban middle class (n = 80) on values and goals for themselves and their newborn children. Terminal values of inner-city women for themselves related more to social and religious goals in contrast to the more intrapersonal and personal goals of middle-class women. Instrumental values of inner-city women for their newborn children demonstrated concern with conformity and control, whereas for the middle class there was more concern with competence. Goals for the near future of the inner-city mothers were based on a desire for jobs and education.