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Background: Learning which letters correspond to which speech sounds is fundamental for learning to read. Based on previous experimental studies, we developed a serious game aiming to boost letter-speech sound (L-SS) correspondences in a motivational game environment. Objectives: The goal of this study was to determine the efficacy of this game in training L-SS correspondences in pre-readers. Additionally, an extended version of the game was developed given the importance of handwriting in audio-visual integration. We established whether including a motoric component in the game boosted the letter-speech sound training on top of the effect of the game without the motoric component. Methods: One-hundred forty-five kindergartners were randomly allocated to play either the standard audio-visual version of the game, the motoric version or a control math game. All children were pre- and post-tested on L-SS knowledge and reading accuracy. Results and conclusions: We found that playing the game enhanced pre-readers' L-SS knowledge, but not reading accuracy, after a short, intensive intervention period of 3 weeks. However, children who played the motoric version of the game did not differ significantly from either the standard or the control condition. Implications: This game was efficient in training L-SS correspondences in pre-readers. These results suggest that this game might be useful as a preventive evidence-based intervention for at-risk children in kindergarten who might benefit from a head start before learning how to read. Future studies are needed to examine whether a longer intervention period results in L-SS knowledge being translated into reading skills.

This study examined how top-down control influenced letter-speech sound (L-SS) learning, the initial phase of learning to read. In 2020, 107 Dutch children (53 boys, M[subscript age] = 106.845 months) learned eight L-SS correspondences, either preceded by goal-directed or implicit instructions. Symbol knowledge and artificial word-reading ability were assessed immediately after learning and on the subsequent day to examine the effect of sleep. Goal-directed children were faster and more efficient in learning a new script and had better learning outcomes compared to children who were not instructed about the goal of the task. This study demonstrates that directing children toward the goal can promote L-SS learning and consolidation, giving insights into how top-down control influences the initial phase of reading acquisition.

To identify neuroimaging biomarkers of alcohol dependence (AD) from structural magnetic resonance imaging, it may be useful to develop classification models that are explicitly generalizable to unseen sites and populations. This problem was explored in a mega-analysis of previously published datasets from 2,034 AD and comparison participants spanning 27 sites curated by the ENIGMA Addiction Working Group. Data were grouped into a training set used for internal validation including 1,652 participants (692 AD, 24 sites), and a test set used for external validation with 382 participants (146 AD, 3 sites). An exploratory data analysis was first conducted, followed by an evolutionary search based feature selection to site generalizable and high performing subsets of brain measurements. Exploratory data analysis revealed that inclusion of case- and control-only sites led to the inadvertent learning of site-effects. Cross validation methods that do not properly account for site can drastically overestimate results. Evolutionary-based feature selection leveraging leave-one-site-out cross-validation, to combat unintentional learning, identified cortical thickness in the left superior frontal gyrus and right lateral orbitofrontal cortex, cortical surface area in the right transverse temporal gyrus, and left putamen volume as final features. Ridge regression restricted to these features yielded a test-set area under the receiver operating characteristic curve of 0.768. These findings evaluate strategies for handling multi-site data with varied underlying class distributions and identify potential biomarkers for individuals with current AD.

The Abbreviated Math Anxiety Scale (AMAS) is commonly used to compare groups on math anxiety. Group comparisons should however be preceded by a demonstration of metric and scalar measurement invariance, which is currently only available for undergraduate students in the USA. This study tested for metric and scalar measurement invariance of AMAS scores across sexes and age groups and investigated reliability and validity evidence. Dutch secondary school students (N = 1504) and university students (N = 629) completed the AMAS and reported their math grades. Subsamples also completed questionnaires on related (e.g., trait anxiety) and unrelated constructs (e.g., anxiety for learning a foreign language). Results of multi-group Confirmatory Factor Analyses showed the 2-factor structure that was detected in earlier studies and supported partial metric and scalar invariance, although cross-loadings for one item were included for the female university students group to improve model fit. Reliability ranged from acceptable to good and validity was supported.

Brain asymmetry reflects left-right hemispheric differentiation, which is a quantitative brain phenotype that develops with age and can vary with psychiatric diagnoses. Previous studies have shown that substance dependence is associated with altered brain structure and function. However, it is unknown whether structural brain asymmetries are different in individuals with substance dependence compared with nondependent participants. Here, a mega-analysis was performed using a collection of 22 structural brain MRI datasets from the ENIGMA Addiction Working Group. Structural asymmetries of cortical and subcortical regions were compared between individuals who were dependent on alcohol, nicotine, cocaine, methamphetamine, or cannabis (n = 1,796) and nondependent participants (n = 996). Substance-general and substance-specific effects on structural asymmetry were examined using separate models. We found that substance dependence was significantly associated with differences in volume asymmetry of the nucleus accumbens (NAcc; less rightward; Cohen's d = 0.15). This effect was driven by differences from controls in individuals with alcohol dependence (less rightward; Cohen's d = 0.10) and nicotine dependence (less rightward; Cohen's d = 0.11). These findings suggest that disrupted structural asymmetry in the NAcc may be a characteristic of substance dependence.

The choice of cortisol sampling times in early childhood studies varies widely. Given that recommendations on sampling protocols are largely based on adults, the present study aimed to broaden current knowledge by examining how reliably cortisol measures obtained at different daytimes would reveal between-individual differences in toddlers' cortisol levels. Parents were instructed to take 10 saliva samples consecutively (five per day) from their toddler (N = 19; M[subscript age] = 15.8 months, SD[subscript age] = 4.2 months). Intra-class correlations (ICCs) were computed to evaluate cortisol reliability. Cortisol samples taken in the morning between 30 and 80 min after awakening and bedtime samples were most reliable in differentiating between children (ICCs [greater than or equal to] 0.80). Wake-up cortisol samples taken within the first 30 min after awakening and afternoon samples showed moderate reliabilities (ICCs = 0.64), whereas the reliability of noon samples was poor (ICC = 0.43). Therefore, when investigating cortisol in young children while being restricted to a few samples only, assessing cortisol in the morning (at least 30 min after awakening) and at bedtime would be advisable.

While imaging studies have demonstrated volumetric differences in subcortical structures associated with dependence on various abused substances, findings to date have not been wholly consistent. Moreover, most studies have not compared brain morphology across those dependent on different substances of abuse to identify substance-specific and substance-general dependence effects. By pooling large multinational datasets from 33 imaging sites, this study examined subcortical surface morphology in 1628 nondependent controls and 2277 individuals with dependence on alcohol, nicotine, cocaine, methamphetamine, and/or cannabis. Subcortical structures were defined by FreeSurfer segmentation and converted to a mesh surface to extract two vertex-level metrics-the radial distance (RD) of the structure surface from a medial curve and the log of the Jacobian determinant (JD)-that, respectively, describe local thickness and surface area dilation/contraction. Mega-analyses were performed on measures of RD and JD to test for the main effect of substance dependence, controlling for age, sex, intracranial volume, and imaging site. Widespread differences between dependent users and nondependent controls were found across subcortical structures, driven primarily by users dependent on alcohol. Alcohol dependence was associated with localized lower RD and JD across most structures, with the strongest effects in the hippocampus, thalamus, putamen, and amygdala. Meanwhile, nicotine use was associated with greater RD and JD relative to nonsmokers in multiple regions, with the strongest effects in the bilateral hippocampus and right nucleus accumbens. By demonstrating subcortical morphological differences unique to alcohol and nicotine use, rather than dependence across all substances, results suggest substance-specific relationships with subcortical brain structures.

Many studies have reported that heavy substance use is associated with impaired response inhibition. Studies typically focused on associations with a single substance, while polysubstance use is common. Further, most studies compared heavy users with light/non-users, though substance use occurs along a continuum. The current mega-analysis accounted for these issues by aggregating individual data from 43 studies (3610 adult participants) that used the Go/No-Go (GNG) or Stop-signal task (SST) to assess inhibition among mostly "recreational" substance users (i.e., the rate of substance use disorders was low). Main and interaction effects of substance use, demographics, and task-characteristics were entered in a linear mixed model. Contrary to many studies and reviews in the field, we found that only lifetime cannabis use was associated with impaired response inhibition in the SST. An interaction effect was also observed: the relationship between tobacco use and response inhibition (in the SST) differed between cannabis users and non-users, with a negative association between tobacco use and inhibition in the cannabis non-users. In addition, participants' age, education level, and some task characteristics influenced inhibition outcomes. Overall, we found limited support for impaired inhibition among substance users when controlling for demographics and task-characteristics.

High perceived stress is associated with psychological and academic difficulties among college students. In this study, we aimed to investigate associations of student status (international vs domestic student in the Netherlands) with eight common sources of stress (i.e., financial, health, love life, relationship with family, relationship with people at work/ school, the health of loved ones, other problems of loved ones, and life in general). Participants were 2,196 college students (domestic: n = 1,642, international: n = 554) from two universities in Amsterdam, the Netherlands. Hierarchical linear regression analyses were used to estimate associations of student status with all eight sources of stress. Student status was significantly associated with higher levels of perceived stress in almost all life domains. International student status was significantly associated with higher perceived stress in the domains of financial situation and health of loved ones after adjusting for sociodemographic characteristics, depressive and anxiety symptoms, and other sources of stress. Findings highlight that several differences exist in the magnitude of perceived stress in certain areas between international and domestic students in the Netherlands. Consequently, it is essential to uncover the different needs of college students and develop specific strategies to deliver the most suitable services. [ABSTRACT FROM AUTHOR]