The Role of Expectations in Effective Genetic Counseling

The goals for this investigation were to assess individuals' expectations for social support from genetic counselors, and to explore how these expectations influence perceptions of genetic counselor effectiveness. Two studies were conducted to address these goals. Results from the first study show that individuals most frequently expect genetic counselors to provide options and support following the disclosure of distressing test results, while data from the second study demonstrate that expectations play a significant role in individuals' assessment of genetic counselor effectiveness. These findings shed light on what individuals expect from genetic counselors following the disclosure of medically positive test results and inform how these expectations influence the success of genetic counseling sessions.     

Male HIV-1 transgenic rats show reduced cocaine-maintained lever-pressing compared to F344 wildtype rats despite similar baseline locomotion

The HIV-1 transgenic (Tg) rat model is valuable for understanding HIV-associated neurocognitive disorders (HAND) and accompanying substance use and misuse. Tg and F344/NHsd wildtype (WT) rats were allowed to self-administer intrajugular cocaine. For the first 7 sessions, neither genotype self-administered cocaine (0.1 mg/kg/infusion) on a fixed ratio 1 schedule. We thus implemented a lever–cocaine “autoshaping” session followed by a series of manipulations changing dose and reinforcement schedule. Tg rats self-administered much less cocaine than WT rats throughout the study. Of 8 Tg rats, 5 modestly increased self-administration from sessions 36–50. Of those, only 3 showed a lever discrimination. Of 10 WT rats, 8 acquired robust self-administration by session 19; all WT rats self-administered cocaine by the end of the study. WT and Tg rats had similar baseline locomotor activity in the self-administration chamber suggesting that the low levels of cocaine intake in the Tg rats did not reflect a nonspecific motor impairment in this rat strain. Concomitant measurement of activity with self-administration revealed activity increases that followed increased cocaine intake. That relation held in Tg rats. Therefore, the present study provides evidence that HIV-1 Tg rats are less sensitive to the reinforcing effects of cocaine than their F344 WT counterparts.     

Maternal correlates of stability and change in infant-mother attachment

The relations between maternal control style, sensitivity, and childrearing attitudes on one hand and the stability of the infant-mother attachment relationship on the other were examined in a sample of 38 mother-infant dyads. The mother-child pairs were observed during a structured play session and in Ainsworth's Strange Situation when the infants were 12 and 20 months old, a developmental period characterized by increased autonomous functioning. Our results suggested that infants whose mothers had nonpunitive childrearing attitudes, were sensitive, and supportive of their infants' striving toward autonomy remained, or became, secure in their attachment relationship over their second year of life. Mothers who were more punitive, more controlling, and less sensitive had infants who either remained or became insecurely attached across this developmental period. While previous research has linked attachment stability to socioeconomic factors, the present investigation points to the importance of more subtle interactive variables to the understanding of the attachment relationship.     

Effectiveness of DRO tokens in decreasing disruptive behavior in the classroom with five multiply handicapped children

In this study the effectiveness of differential reinforcement of other behavior (DRO) with tokens was assessed in the treatment of various topographies of disruptive behavior in the classroom with five children who were multiply handicapped. Prior to implementation of the treatment, reinforcer assessment was conducted to identify items to be used as back-up reinforcers. Data were analyzed using time-series analysis. Results show that DRO tokens were highly effective in decreasing disruptive behavior of all participants. ©1997 by John Wiley & Sons, Ltd.     

Genetic and environmental influences on academic achievement trajectories during adolescence

Most studies have considered the effects of particular characteristics on academic achievement individually, which means that little is known about how they function together. Using the population-based Minnesota Twin Family Study, the authors investigated the effects of child academic engagement (interest, involvement, effort), IQ, depression, externalizing behavior, and family environmental risk on academic achievement (reported school grades) from ages 11 through 17. Hierarchical linear growth curve modeling showed main effects on initial reported Grades for all variables, and IQ mitigated the deleterious effects of family risk and externalizing. Only engagement affected change in Grades through adolescence. Influences on initial Grades were strongly genetically influenced, associated primarily with IQ, engagement, and externalizing behavior. Shared environmental influences on initial Grades linked engagement, IQ, and family risk. Genetic influences on change in Grades were substantial, but they were not associated with the academic, family risk, and mental health covarying factors. These results indicate that age 11 achievement and change in achievement through adolescence show systematic patterns and document the existence of individual differences in the commonly shared developmental experience of adapting to the school environment.     

Emotion-modulated performance and activity in left dorsolateral prefrontal cortex

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).     

Two-digit comparison: decomposed, holistic, or hybrid?

We investigate whether two-digit numbers are decomposed for purposes of numerical comparison (e.g., choosing the larger one). Earlier theorists concluded that numbers are processed holistically (Brysbaert, 1995; Dehaene, Dupoux, & Mehler, 1990), or that holistic and decomposed processes operate in parallel (Nuerk, Weger, & Willmes, 2001). In the present experiment, we presented pairs of two-digit numbers with a decade distance of either zero (e.g., 54-57) or one (54-61). If a holistic process contributes to two-digit comparison, there should be an overall distance effect for number pairs with a decade distance of one. On the other hand, if numbers are decomposed and a holistic comparison does not contribute, this overall distance effect should be absent for these number pairs. Evidence is found that, at least in the present task settings, numbers are not compared holistically. The results are interpreted in terms of a recently proposed theory of numerical cognition (Verguts & Fias, 2004; Verguts, Fias, & Stevens, in press).