Change in cognitive functioning associated with apoE genotype in a community sample of older adults

The influence of a genetic risk factor, apolipoprotein E (apoE) epsilon4 variant, was assessed in older adults aged 70 to 94 on 3 occasions over 7 years. The results of latent growth curve analyses are reported for individuals genotyped for apoE at the 2nd measurement occasion (n = 601) and for a subsample of individuals without probable or definite dementia during the 1st or 2nd occasion (n = 434). ApoE-epsilon4 status was a significant predictor of level and change in memory performance and change in speed performance in the full sample, and of initial level and change in memory performance in the nondemented subsample. These results support previous findings that apoE-epsilon4 is associated with accelerated memory deterioration in individuals without clinical dementia.     

The use of reliable digits to detect malingering in a criminal forensic pretrial population

The present research is a cross-validation of previous investigation by Greiffenstein, Baker; and Gola; Greiffenstein, Gola, and Baker; and Meyers and Volbrecht on the reliable digits (RELD) method of detecting suspected malingering on the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The results support the use of the RELD method on a criminalforensic pretrial population (N = 187). Sensitivities, specificities, and incremental hit ratesfor two cut levels of the RELD method, Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency and the Personality Assessment Inventory Negative Impression Scales, as well as multiple combined cut scores, were comparable to those observed in previous studies that used neuropsychologically evaluated participants. The selection of which cut score or combination of cut scores is appropriate on the RELD method is also discussed.     

An examination of organizational and team commitment in a self-directed team environment

A model hypothesizing differential relationships among predictor variables and individual commitment to the organization and work team was tested. Data from 485 members of sewing teams supported the existence of differential relationships between predictors and organizational and team commitment. In particular, intersender conflict and satisfaction with coworkers were more strongly related to team commitment than to organizational commitment. Resource-related conflict and satisfaction with supervision were more strongly related to organizational commitment than to team commitment. Perceived task interdependence was strongly related to both commitment foci. Contrary to prediction, the relationships between perceived task interdependence and the 2 commitment foci were not significantly different. Relationships with antecedent variables help explain how differential levels of commitment to the 2 foci may be formed. Indirect effects of exogenous variables are reported.     

Childhood Gender Nonconformity and Body Dissatisfaction in Gay and Heterosexual Men

Although researchers have long hypothesized a relation between gender role orientation (i.e., masculinity and femininity) and body dissatisfaction, findings have been inconsistent. The current study employed a measure of recalled childhood gender nonconformity to examine gender role behaviors in association with body dissatisfaction among an ethnically diverse (76% Caucasian, 2% African American, 8% Asian, and 16.4% Hispanic American) group of predominantly college-aged males of both homosexual (n = 129) and heterosexual (n = 52) orientation. Consistent with past research, gay males reported more body dissatisfaction and recalled more childhood gender atypical behaviors (e.g., disliking athletics, playing with dolls). Group differences in body dissatisfaction, however, disappeared when childhood gender nonconformity was statistically controlled, suggesting childhood atypical gender role behavior may place males at greater risk for adult body dissatisfaction. A within-group analysis also found that a high feminine subtype of gay males had greater body dissatisfaction than less feminine subtypes had. Results support the assertion that gender role behaviors may contribute to body dissatisfaction among gay males.     

Selection and inhibition in infancy: evidence from the spatial negative priming paradigm

We used a spatial negative priming (SNP) paradigm to examine visual selective attention in infants and adults using eye movements as the motor selection measure. In SNP, when a previously ignored location becomes the target to be selected, responses to it are impaired, providing a measure of inhibitory selection. Each trial consisted of a prime and a probe, separated by 67, 200, or 550 ms interstimulus intervals (ISIs). In the prime, a target was accompanied by a distractor. In the probe, the target appeared either in the location formerly occupied by the distractor (ignored repetition) or in another location (control). Adults exhibited the SNP effect in all three ISI conditions, producing slower saccade latencies on ignored repetition versus control trials. The SNP effect obtained for infants only under 550 and 200 ms ISI conditions. These results suggest that important developments in visual selection are rooted in emerging inhibitory mechanisms.     

Effect of stimulant medication on lower extremity response time of boys with attention deficit hyperactivity disorder

Children with attention deficit hyperactivity disorder (ADHD) have been labeled as "inefficient movers"; however, little research has examined the effect of stimulant medication on lower extremity movements. 16 boys, 11 to 13 years old, with ADHD performed a lower-limb choice-response time task, both on and off medication. When nonmedicated, children had significantly slower reaction times to all three targets and significantly slower movement times for the contralateral and midline movements. For both conditions, children had significantly faster movement time when using the right leg than the left leg. These findings suggest that movement characteristics of children with ADHD are different under medicated and nonmedicated situations.     

A conceptual and psychometric framework for distinguishing categories and dimensions

An important, sometimes controversial feature of all psychological phenomena is whether they are categorical or dimensional. A conceptual and psychometric framework is described for distinguishing whether the latent structure behind manifest categories (e.g., psychiatric diagnoses, attitude groups, or stages of development) is category-like or dimension-like. Being dimension-like requires (a) within-category heterogeneity and (b) between-category quantitative differences. Being category-like requires (a) within-category homogeneity and (b) between-category qualitative differences. The relation between this classification and abrupt versus smooth differences is discussed. Hybrid structures are possible. Being category-like is itself a matter of degree; the authors offer a formalized framework to determine this degree. Empirical applications to personality disorders, attitudes toward capital punishment, and stages of cognitive development illustrate the approach.     

Updating target location at the end of an orienting saccade affects the characteristics of simple point-to-point movements

Six results are reported. (a) Reaching accuracy increases when visual capture of the target is allowed (e.g., target on vs. target off at saccade onset). (b) Whatever the visual condition, trajectories diverge only after peak acceleration, suggesting that accuracy is improved through feedback mechanisms. (c) Feedback corrections are smoothly implemented, causing the corrected and uncorrected velocity profiles to exhibit similar shapes. (d) Initial kinematics poorly predict final accuracy whatever the condition, indicating that target capture is not the only critical input for feedback control. (e) Hand and eye final variability are unrelated, suggesting that gaze direction is not a target signal for arm control. (f) Extent errors are corrected without modification of movement straightness; direction errors cause path curvature to increase. Together these data show that movements with straight paths and bell-shaped velocity profiles are not necessarily ballistic.