Explore the vast range of titles available.

This study investigates the effects of fitness changes on hippocampal microstructure and hippocampal volume. Fifty-two healthy participants aged 59–74years with a sedentary lifestyle were randomly assigned to either of two levels of exercise intensity. Training lasted for six months. Physical fitness, hippocampal volumes, and hippocampal microstructure were measured before and after training. Hippocampal microstructure was assessed by mean diffusivity, which inversely reflects tissue density; hence, mean diffusivity is lower for more densely packed tissue. Mean changes in fitness did not differ reliably across intensity levels of training, so data were collapsed across groups. Multivariate modeling of pretest–posttest differences using structural equation modeling (SEM) revealed that individual differences in latent change were reliable for all three constructs. More positive changes in fitness were associated with more positive changes in tissue density (i.e., more negative changes in mean diffusivity), and more positive changes in tissue density were associated with more positive changes in volume. We conclude that fitness-related changes in hippocampal volume may be brought about by changes in tissue density. The relative contributions of angiogenesis, gliogenesis, and/or neurogenesis to changes in tissue density remain to be identified. •Higher training-induced changes in fitness are associated with more positive changes in hippocampal tissue density.•Increased hippocampal tissue density relates to more positive changes in hippocampal volume.•Changes in hippocampal microstructure may mediate training-induced changes in hippocampal volume among sedentary older adults.

The task-switching paradigm is deemed a measure of cognitive flexibility. Previous research has demonstrated that individual differences in task-switch costs are moderately inversely related to cognitive ability. However, current theories emphasize multiple component processes of task switching, such as task-set preparation and task-set inertia. The relations of task-switching processes with cognitive ability were investigated in the current study. Participants completed a task-switching paradigm with geometric forms and a visuospatial working memory capacity (WMC) task. The task-switch effect was decomposed with the diffusion model. Effects of task-switching and response congruency were estimated as latent differences using structural equation modeling. Their magnitudes and relations with visuospatial WMC were investigated. Effects in the means of parameter estimates replicated previous findings, namely increased non-decision time in task-switch trials. Further, task switches and response incongruency had independent effects on drift rates, reflecting their differential effects on task readiness. Findings obtained with the figural tasks employed in this study revealed that WMC was inversely related to the task-switch effect in non-decision time. Relations with drift rates were inconsistent. Finally, WMC was moderately inversely related to response caution. These findings suggest that more able participants either needed less time for task-set preparation or that they invested less time for task-set preparation.

Face cognition performance is related to individual differences in cognitive subprocesses, as reflected in the amplitudes and latencies of event-related brain potentials (ERPs; Herzmann, Kunina, Sommer, & Wilhelm, 2010 ). In order to replicate and extend these findings, 110 participants were tested on a comprehensive task battery measuring face cognition abilities and established cognitive abilities, followed by ERP recordings in a face-learning-and-recognition task. We replicated the links of the ERP components indicating the speed of structural face encoding (N170 latency) and access to structural representations in memory (early repetition effect [ERE]/N250r) with the accuracy and speed of face cognition and with established cognitive abilities. As a novel result, we differentiated between the accuracy of face perception and face memory on the behavioral and electrophysiological levels and report a relationship between basic visual processes (P100 amplitude) and face memory. Moreover, the brain–behavior relationships for the ERE/N250r held true, even though we eliminated pictorial and perceptual structural codes from the priming effects by using backward masking of the primes with novel unfamiliar faces. On a methodological level, we demonstrated the utility of the latent difference score modeling technique to parameterize ERP difference components (e.g., ERE/N250r) on a latent level and link them to face cognition abilities.

Multiple predictors have been associated with persistent somatic symptoms. However, previous studies problematically defined the persistence of symptoms, conflated participants' sex and gender, and focused on patient populations. Therefore, we studied associations between predictors, especially sex and gender, and longitudinal patterns of somatic symptoms in the general adult population. We also assessed whether predictors for persisting symptoms differ between sexes. To identify developmental trajectories of somatic symptoms, assessed by the SCL-90 SOM, we used latent class trajectory modeling in the Dutch Lifelines Cohort Study [ = 150 494; 58.6% female; median time to follow-up: 46.0 (min-max: 22.0-123.0) months]. To identify predictors of trajectories, we applied multiple logistic regression analyses. Predictors were measured by surveys at baseline and a composite gender index was previously developed. A five-class linear LCGA model fitted the data best: 93.7% of the population had a stable symptom trajectory, whereas 1.5% and 4.8% of the population had a consistently increasing or decreasing symptom trajectory, respectively. Female sex predicted severe, stable symptom severity (OR 1.74, 95% CI 1.36-2.22), but not increasing symptom severity (OR 1.15, 95% CI 0.99-1.40). Femininity was protective hereof (OR 0.60, 95% CI 0.44-0.82 and OR 0.66, 95% CI 0.51-0.85, respectively). Merely a few predictors of symptom severity, for instance hours of paid employment and physical functioning, differed in strength between sexes. Yet, effect sizes were small. Female sex and femininity predict symptom trajectories. No large sex differences in the strength of additional predictors were found, thus it may not be clinically useful to distinguish between predictors specific to male or female patients of persistent somatic symptoms.

Individual differences in temperament have been well-described, but individual differences in temperament trajectories require elaboration. Specifically, it is unknown if subgroups of infants display different developmental patterns and if these patterns relate to later behavioral problems. The aims were to identify distinct developmental patterns in broad dimensions of temperament among typically developing infants, to determine whether these developmental patterns differ by sex, to evaluate how developmental patterns within each dimension of temperament relate to developmental patterns within other dimensions of temperament, and to determine whether developmental patterns of infant temperament are associated with internalizing and externalizing behavior at 2 years of age. Data from the longitudinal Alberta Pregnancy Outcomes and Nutrition study (n = 1,819) were used to model latent class trajectories of parent-reported infant temperament at 3, 6, and 12 months. Four to five unique latent trajectories were identified within each temperament dimension. Sex was not associated with trajectory groups. Developmental coordination was observed between trajectories of negative emotionality and regulatory capacity, and between regulatory capacity and positive affect, but not between positive affect and negative emotionality. Negative emotionality and regulatory capacity predicted internalizing and externalizing behavior. Patterns of development in infant temperament, and not just intensity of temperament, contribute toward later problem behavior.

Recently, sexual health scholars have expressed concerns regarding adolescents’ use of sexually explicit internet materials (SEIM) during the COVID-19 pandemic. Therefore, using latent growth curve modeling, the current study explored adolescents’ changes in the frequency of SEIM use before, during, and after a strict lockdown period was established in Belgium. Attention was given to individual differences (i.e., gender, gender identity, sexual orientation, pubertal timing, and sensation seeking). A three-wave panel study over a 15-month period among 522 adolescents was used ( M age  = 15.36, SD = 1.51, 67.1% girls). In general, SEIM use did not significantly increase over a 15-month period in the context of the COVID-19 pandemic. Only gender predicted a change in SEIM use frequencies with girls showing a greater, increasing change of SEIM use than boys. When addressing why adolescents used SEIM during a strict lockdown period, sexual arousal, stress, and boredom regulation motivations emerged as the most prevalent motivations. Loneliness regulation was the least prominent motivation. Individual differences were found regarding the gratifications sought according to adolescents’ gender, pubertal timing, and sensation seeking. The findings offer a response to sexual scholars’ worries in terms of adolescents’ SEIM use during the COVID-19 pandemic.

Although there is increasing attention for the interrelationship between obsessive–compulsive personality disorder (OCPD) and obsessive–compulsive disorder (OCD), their shared characteristics in terms of childhood trait antecedents remain understudied. Perfectionism may be a viable candidate trait antecedent, given its role in the clinical manifestation of both OCPD and OCD in adulthood, and the evidence that perfectionism reflects a dispositional tendency observable from childhood onwards. However, little is known about childhood trajectories of perfectionism with prospective links to later OCPD versus OCD. Using latent growth curve modeling, this study explored the baseline and growth of childhood perfectionism in 485 community and referred children (55.5% girls, 7.17–14.78 years old, Mage = 10.74, SD = 1.50) across three waves. Adolescent OCPD traits and OCD symptoms were measured in Wave 4. An overall decreasing trend of perfectionism from childhood through adolescence appeared, without inter-individual differences in growth. Individual differences in baseline levels of childhood perfectionism were significant, and equally predicting adolescent OCPD and OCD outcomes. At a more specific level, childhood perfectionism predicted most strongly the rigid perfectionism component of OCPD, and the orderliness/cleanliness/perfectionism and obsession domain of OCD. This demonstrates the value of childhood perfectionism for understanding differential outcomes of adolescent OCPD traits and OCD symptoms.

Social work researchers often use variable-centered approaches such as regression and factor analysis. However, these methods do not capture important aspects of relationships that are often imbedded in the heterogeneity of samples. Latent class analysis (LCA) is one of several person-centered approaches that can capture heterogeneity within and between groups. This method is illustrated in the present study, in which LCA is used to explicate differences in symptomatology in a nonclinical, national representative sample of youths. Data (N = 14,738) from the National Longitudinal Study of Adolescent Health were analyzed using externalizing and internalizing behavioral constructs and then validated against a number of sociodemographic characteristics and behavior outcomes typically associated with type and severity of symptomatology. Findings revealed important differences within the externalizing symptomatology construct and class differences across racial and ethnic groups, gender, age categories, and several behavior outcomes. Research and clinical implications on the importance of modeling heterogeneity using a person-centered approach are discussed.

In current numerical work, a mathematical model for an air collector with latent heat storage is established and solved using the finite difference method. The glass, absorber plate, and air flow temperatures are described in one-dimensional unsteady terms. The storage material simulation is formed by a two-dimensional unsteady modeling and solved using the enthalpy method. By analyzing the temperature distribution and phase change behavior within the PCM using a two-dimensional unsteady model, this research provides a more detailed understanding of the thermal storage process compared to studies employing one-dimensional models. The mathematical model was validated by an outdoor experiment under prevailing climatic conditions in Ho Chi Minh City, Vietnam. The absorber plate is equipped with longitudinal rectangular fins to enhance heat transfer. Height of storage material, air flow rate and fin geometries are set as independent parameters to investigate phase change in latent storage and daily performance. Simulation results show that a storage height of 20 cm is suitable to fully liquify and to extend the operating time to 21:00. Attaching the fins increases the daily efficiency up to 13.7% compared to that of a smooth duct air collector. Latent heat storage provides the most uniform outlet air temperature compared to sensible storage and without storage. The standard deviation of outlet air temperature with time of day is 6.34 °C, 8.47 °C, and 9.20 °C for the types of latent heat storage, sensible heat storage, and without storage, respectively.

Bidirectional relations have long been of interest in psychology and other social behavioral sciences. In recent years, the widespread use of intensive longitudinal data has provided new opportunities to examine dynamic bidirectional relations between variables. However, most previous studies have focused on the effect of one variable on the other (i.e., cross-lagged effects) rather than the overall effect representing the dynamic interplay between two variables (i.e., feedback effects), which we believe may be due to a lack of relevant methodological guidance. To quantify bidirectional relations as a whole, this study attempted to provide guidance for the estimation and interpretation of feedback effects based on dynamic structural equation models. First, we illustrated the estimation procedure for the average and person-specific feedback effects. Then, to facilitate the interpretation of feedback effects, we established an empirical benchmark by quantitatively synthesizing the results of relevant empirical studies. Finally, we used a set of empirical data to demonstrate how feedback effects can help (a) test theories based on bidirectional relations and (b) reveal correlates of individual differences in bidirectional relations. We also discussed the broad application prospects of feedback effects from a dynamic systems perspective. This study provides guidance for applied researchers interested in further examining feedback effects in bidirectional relations, and the shift from focusing on cross-lagged effects only to a comprehensive consideration of feedback effects may provide new insights into the study of bidirectional relations.