Personality and Substance Use in Midlife: Conscientiousness as a Moderator and the Effects of Trait Change

Personality traits predict substance use in adolescence, but less is known about prospective substance use in middle age and beyond. Moreover, there is growing interest in how personality change and the multiplicative effects among personality traits relate to substance use. Participants included approximately 4000 adults aged 25-74 who participated in two waves of the Midlife in the US (MIDUS) study. Higher levels of neuroticism, extraversion, openness, and lower levels of conscientiousness and agreeableness predicted longitudinal substance use. Increases in neuroticism and openness predicted increased substance use while increases in conscientiousness and agreeableness predicted decreased substance use. Higher levels of conscientiousness moderated two of the other trait main effects. Personality, trait change, and interactions among traits reliably forecasted 10-year substance-use behaviors.     

Sex and ear differences in spontaneous and click-evoked otoacoustic emissions in young adults

Effects of sex and handedness on the production of spontaneous and click-evoked otoacoustic emissions (OAEs) were explored in a non-hearing impaired population (ages 17-25 years). A sex difference in OAEs, either produced spontaneously (spontaneous OAEs or SOAEs) or in response to auditory stimuli (click-evoked OAEs or CEOAEs) has been reported in infants and children, but healthy young adults seldom have been the target of study. In the current data, a robust sexual dimorphism was confirmed, with women producing more numerous and stronger SOAEs, and CEOAEs with greater response amplitude compared to men. A right-ear advantage was found for the number of SOAEs produced and, in women, for SOAE power. Although handedness did not moderate the ear asymmetry in production, exploratory analyses revealed that departures from strong right hand preference were associated in the present sample with reduced numbers or strengths of OAEs. The results are discussed with respect to differential exposure to androgens during prenatal development.     

Intra- and Inter-Individual Differences in Adolescent Depressive Mood: the Role of Relationships with Parents and Friends

Utilizing four waves of data from 1126 secondary school Dutch adolescents (Mage = 13.95 at the first wave; 53% boys), the current study examined the interplay between parent-adolescent and friend-adolescent relationship quality (satisfaction and conflict) in relation to adolescents’ depressive mood. Using multilevel analyses, the interacting effects of parent/friend relationship quality on depressive mood were tested at both the intra- and inter-individual level. Analyses at the intra-individual level investigated whether individual depressive mood fluctuated along with changes in their social relationships regardless of one’s general level of depressive mood; and analyses at the inter-individual level examined whether the average differences in depressive mood between adolescents were associated with different qualities of social relationships. We interpreted the patterns of interactions between parent and friend relationships using four theoretical models: the reinforcement, toxic friends, compensation, and additive model. The results demonstrate the covariation of parent- and friend- relationship quality with adolescents’ depressive mood, and highlight that parent and peer effects are not independent from each other—affirming the compensation and additive models at the intra-individual and the reinforcement and additive models at the inter-individual level. The findings highlight the robustness of the protective effects of parent and peer support and the deleterious effects of conflictual relationships for adolescent mental health. The results have implications for both the theoretical and practical design of (preventive) interventions aimed at decreasing adolescents’ depressive mood.     

Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality): A longitudinal,multi-domain study on sexual development of Dutch adolescents

This study gives an overview of Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality), a four-wave longitudinal study of 1297 Dutch adolescents. First, the sample, measures and four sub-projects are described. Second, hierarchical regression analyses were conducted to examine how key variables from the individual domain (impulsivity), parent domain (parent–adolescent relationship quality), peer domain (involvement with peers) and media domain (time spent on social networking sites), and their interactions predict changes in the experience with sexual behaviour of adolescents across time. Results showed that higher levels of impulsivity, lower quality of relation with parents, more frequent involvement with peers and more time spent on social networking sites at baseline predicted increases in sexual experience of adolescents over a subsequent 1.5-year time period. No interaction effects among the domains were found. The findings highlight the significance of a multi-domain approach to the study of adolescent sexual development.     

Becoming a face expert

Expertise in recognizing facial identity, and, in particular, sensitivity to subtle differences in the spacing among facial features, improves into adolescence. To assess the influence of experience, we tested adults and 8-year-olds with faces differing only in the spacing of facial features. Stimuli were human adult, human 8-year-old, and monkey faces. We show that adults' expertise is shaped by experience: They were 9% more accurate in seeing differences in the spacing of features in upright human faces than in upright monkey faces. Eight-year-olds were 14% less accurate than adults for both human and monkey faces (Experiment 1), and their accuracy for human faces was not higher for children's faces than for adults' faces (Experiment 2). The results indicate that improvements in face recognition after age 8 are not related to experience with human faces and may be related to general improvements in memory or in perception (e.g., hyperacuity and spatial integration).     

The neural correlates of statistical learning in a word segmentation task: An fMRI study

Functional magnetic resonance imaging (fMRI) was used to assess neural activation as participants learned to segment continuous streams of speech containing syllable sequences varying in their transitional probabilities. Speech streams were presented in four runs, each followed by a behavioral test to measure the extent of learning over time. Behavioral performance indicated that participants could discriminate statistically coherent sequences (words) from less coherent sequences (partwords). Individual rates of learning, defined as the difference in ratings for words and partwords, were used as predictors of neural activation to ask which brain areas showed activity associated with these measures. Results showed significant activity in the pars opercularis and pars triangularis regions of the left inferior frontal gyrus (LIFG). The relationship between these findings and prior work on the neural basis of statistical learning is discussed, and parallels to the frontal/subcortical network involved in other forms of implicit sequence learning are considered.     

Inhibition: Mental Control Process or Mental Resource?

The current study tested 2 models of inhibition in 45 children with language impairment and 45 children with normally developing language; children were aged 7 to 12 years. Of interest was whether a model of inhibition as a mental-control process (i.e., executive function) or as a mental resource would more accurately reflect the relations among mental-attentional (M) capacity, inhibition, updating, shifting, and language competence. Children completed measures of M-capacity (in the verbal and nonverbal domains), inhibition, updating, shifting, and language. Path analyses showed the data provided a poor fit to the model of inhibition as a mental-control process but a good fit to the model of inhibition as a mental resource. Results are consistent with the theory of constructive operators and suggest inhibition is a mental resource rather than a mental-control process.     

Converging evidence of configural processing of faces in high-functioning adults with autism spectrum disorders

There is conflicting evidence about whether individuals with autism spectrum disorder (ASD) demonstrate configural processing of faces. We examined two types of configural processing of unfamiliar faces in high-functioning adults with ASD: Holistic processing (processing a face as a gestalt percept) and processing of second-order relations (the spatial relations among facial features, e.g., distance between two eyes). Compared to age- and IQ-matched typical adults, 17 adults with ASD demonstrated normal holistic processing (as demonstrated by the composite face effect), normal sensitivity to second-order relations in upright faces, and the expected disruption of sensitivity to second-order relations in inverted faces. They were also normal in using the internal features and shape of the external contour to make same/different judgements about facial identity. The results provide converging evidence of configural processing of unfamiliar faces in high-functioning adults with ASD, and bring into question the generalizability of previous reports of abnormal face processing in individuals with ASD.