The prefrontal cortex in sleep

Experimental data indicate a role for the prefrontal cortex in mediating normal sleep physiology, dreaming and sleep-deprivation phenomena. During nonrandom-eye-movement (NREM) sleep, frontal cortical activity is characterized by the highest voltage and the slowest brain waves compared to other cortical regions. The differences between the self-awareness experienced in waking and its diminution in dreaming can be explained by deactivation of the dorsolateral prefrontal cortex during REM sleep. Here, we propose that this deactivation results from a direct inhibition of the dorsolateral prefrontal cortical neurons by acetylcholine, the release of which is enhanced during REM sleep. Sleep deprivation influences frontal executive functions in particular, which further emphasizes the sensitivity of the prefrontal cortex to sleep.     

Stressful Life Events: A Revision and Update of the Social Readjustment Rating Scale

The widely used and cited Social Readjustment Rating Scale developed by Holmes and Rahe (1967) was comprehensively revised and updated. The new instrument, containing 51 major life events, was administered to a national sample of 5000. Respondents were asked to rate the stressfulness of each life event on a 1–100 scale. Completed surveys were returned by 3122 individuals (62.4%). Responses were analyzed using repeated measures MANOVA and profile analysis. Major results included: (a) statistically and practically significant differences in mean ratings for the 51 life events; (b) five overlapping themes in the top 20 rated life events—death and dying, healthcare, crime and the criminal justice system, financial/economic issues, and family-related issues; and (c) an amazing level of agreement concerning perceived life event stressfulness, regardless of gender, age, or income level.     

Conditions for factor (in)determinacy in factor analysis

The subject of factor indeterminacy has a vast history in factor analysis (Guttman, 1955; Lederman, 1938; Wilson, 1928). It has lead to strong differences in opinion (Steiger, 1979). The current paper gives necessary and sufficient conditions for observability of factors in terms of the parameter matrices and a finite number of variables. Five conditions are given which rigorously define indeterminacy. It is shown that (un)observable factors are (in)determinate. Specifically, the indeterminacy proof by Guttman is extended to Heywood cases. The results are illustrated by two examples and implications for indeterminacy are discussed.     

Safer Sex in Social Context: Individualistic and Relational Determinants of AIDS‐Preventive Behavior Among Gay Men1

This longitudinal study of gay men examined safer sex within steady relationships and assessed whether relationship quality influenced safer sex with casual partners. The theoretical frameworks of Rusbult's (1980) investment model of romantic relationships and of Ajzen's (1988, 1991) model of planned behavior were used. Unprotected intercourse with a steady partner was practiced significantly more often when both partners in a steady relationship were seronegative and had an explicit agreement to keep it safe with casual partners. However, there was no indication that explicit agreements reduced the occurrence of unsafe extrarelational sex. Both the investment model of romantic relationships and the model of planned behavior were successful in accounting for sexual risk behavior outside the relationship.     

Personality Maturation during the Transition to Working Life: Associations with Commitment as a Possible Indicator of Social Investment

The social investment theory (SIT) proposes that personality maturation is triggered by transitions into age‐graded roles and psychological commitment to these roles. The present study examines the predictions of SIT by focusing on the transition from student life to working life. We analysed three‐wave longitudinal data and compared participants who made the transition into working life (N = 226), participants who combined education with work (N = 387), and participants who did not make the transition at all (N = 287). In contrast to the predictions of SIT, we found no differences in personality maturation between individuals who made the transition into working life and those who did this only partly or not at all. Psychological commitment to work did not explain individual differences in personality maturation for those who made the transition (partly) into working life after controlling for multiple testing. Therefore, the present study did not support the predictions of SIT. © 2019 The Authors European Journal of Personality published by John Wiley & Sons Ltd on behalf of European Association of Personality Psychology     

Impaired appetitively as well as aversively motivated behaviors and learning in PDE10A-deficient mice suggest a role for striatal signaling in evaluative salience attribution

Phosphodiesterase 10A (PDE10A) hydrolyzes both cAMP and cGMP, and is a key element in the regulation of medium spiny neuron (MSN) activity in the striatum. In the present report, we investigated the effects of targeted disruption of PDE10A on spatial learning and memory as well as aversive and appetitive conditioning in C57BL/6 J mice. Because of its putative role in motivational processes and reward learning, we also determined the expression of the immediate early gene zif268 in striatum and anterior cingulate cortex. Animals showed decreased response rates in scheduled appetitive operant conditioning, as well as impaired aversive conditioning in a passive avoidance task. Morris water maze performance revealed not-motor related spatial learning and memory deficits. Anxiety and social explorative behavior was not affected in PDE10A-deficient mice. Expression of zif268 was increased in striatum and anterior cingulate cortex, which suggests alterations in the neural connections between striatum and anterior cingulate cortex in PDE10A-deficient mice. The changes in behavior and plasticity in these PDE10A-deficient mice were in accordance with the proposed role of striatal MSNs and corticostriatal connections in evaluative salience attribution.     

Boundaries to the articulation of possible selves through social networking sites: the case of Facebook profilers' social connectedness

This study aims to contribute to an emerging literature that seeks to understand how identity markers on social networking sites (SNSs) shape interpersonal impressions, and particularly the boundaries that SNSs present for articulating unconstrained "hoped-for possible selves." An experiment employing mock-up Facebook profiles was conducted, showing that appearing with friends on a Facebook profile picture as well as increasingly higher number of Facebook friends strengthened perceptions of a profiler's hoped-for level of social connectedness. Excessive numbers of friends, however, weakened perceptions of a profiler's real-level social connectedness, particularly among participants with smaller social networks on Facebook themselves. The discussion focuses on when people come to find that reasonable boundaries of self-generated information on an SNS have been exceeded.     

A developmental typology of adolescent personality

The purpose of the current study is to examine whether Block's personality types (i.e. Resilients, Undercontrollers and Overcontrollers) are replicable as developmental trajectories. We applied a Latent Class Growth Analysis (LCGA) framework to five‐ annual‐wave data on a sample of early to middle adolescents (n = 923). Our results showed that Block's Resilients, Undercontrollers and Overcontrollers are indeed replicable as developmental trajectories across adolescence. These developmental types were related to problem behaviour in a similar way as types found in studies using cross‐sectional data. As such, Resilients reflected low levels of problem behaviour, Undercontrollers had high levels of delinquency and Overcontrollers had high levels of depression. Implications and suggestions for further research are discussed. Copyright © 2009 John Wiley & Sons, Ltd.