Measures Of General Cognitive Ability Research Articles

The validity of general cognitive ability predicting job-specific performance is stable across different levels of job experience.

Decades of research in industrial-organizational psychology have established that measures of general cognitive ability (g) consistently and positively predict job-specific performance to a statistically and practically significant degree across jobs. But is the validity of g stable across different levels of job experience? The present study addresses this question using historical large-scale data across 31 diverse military occupations from the Joint-Service Job Performance Measurement/Enlistment Standards Project (N = 10,088). Across all jobs, results of our meta-analysis find near-zero interactions between Armed Forces Qualification Test score (a composite of math and verbal scores) and time in service when predicting job-specific performance. This finding supports the validity of g for predicting job-specific performance even with increasing job experience and provides no evidence for diminishing validity of g. We discuss the theoretical and practical implications of these findings, along with directions for personnel selection research and practice. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Task fMRI paradigms may capture more behaviorally relevant information than resting-state functional connectivity

Characterizing the optimal fMRI paradigms for detecting behaviorally relevant functional connectivity (FC) patterns is a critical step to furthering our knowledge of the neural basis of behavior. Previous studies suggested that FC patterns derived from task fMRI paradigms, which we refer to as task-based FC, are better correlated with individual differences in behavior than resting-state FC, but the consistency and generalizability of this advantage across task conditions was not fully explored. Using data from resting-state fMRI and three fMRI tasks from the Adolescent Brain Cognitive Development Study ® (ABCD), we tested whether the observed improvement in behavioral prediction power of task-based FC can be attributed to changes in brain activity induced by the task design. We decomposed the task fMRI time course of each task into the task model fit (the fitted time course of the task condition regressors from the single-subject general linear model) and the task model residuals, calculated their respective FC, and compared the behavioral prediction performance of these FC estimates to resting-state FC and the original task-based FC. The FC of the task model fit was better than the FC of the task model residual and resting-state FC at predicting a measure of general cognitive ability or two measures of performance on the fMRI tasks. The superior behavioral prediction performance of the FC of the task model fit was content-specific insofar as it was only observed for fMRI tasks that probed similar cognitive constructs to the predicted behavior of interest. To our surprise, the task model parameters, the beta estimates of the task condition regressors, were equally if not more predictive of behavioral differences than all FC measures. These results showed that the observed improvement of behavioral prediction afforded by task-based FC was largely driven by the FC patterns associated with the task design. Together with previous studies, our findings highlighted the importance of task design in eliciting behaviorally meaningful brain activation and FC patterns.

A digital biomarker for remote self‐assessment of Alzheimer’s Diseases: development and validation

AbstractBackgroundOnline data‐collection provide an opportunity for Alzheimer’s Disease research to collect large datasets crucial for understanding important public health concerns. However, the reliability of online tasks as compared to those administered in the lab is poorly examined. Our goal is to validate an online version of the short‐term memory‐binding task (STMBT), a potential digital biomarker sensitive to Alzheimer’s Disease (Parra et al., 2010), to understand if data collected online in two environments, at‐home and in the lab, is comparable.MethodWe created an online version of the STMBT task using Psytoolkit (Stoet 2010; Stoet 2017). Development involved piloting, group and user discussions to explore how such a novel tool could be best presented for self‐assessment. Useful insights led to refinement of the online tool (i.e., instruction videos, images, and text). The validation stage involves test‐retest reliability assessment of cognitively fit participants (aged >40 years) who complete the two conditions of this paradigm (i.e., shape only and binding). Task Environment (home and in the lab) and conditions (shape and binding) were fully counterbalanced. Measures of general cognitive abilities, anxiety and at‐home environment were also taken.ResultRecruitment is on‐going, but preliminary data (n = 10) has already proved informative. A repeated measures ANOVA looking at task‐accuracy with factors of Environment (home vs. lab) and Condition (shape vs. binding) revealed no significant effects of Environment: F(1, 9) = 0.308, p = .591; Condition: F(1, 9) = 2.202, p = .172); or Interaction: F(1, 9) = 0.308, p = .591). For the shape condition, all participants performed near ceiling regardless of testing environment. In the binding condition, we observed good‐to‐excellent test‐retest reliability between environments using single measures interclass correlation (ICC = 0.954, CI 0.83‐0.99, (F(9, 9) = 39.62, p <.001).ConclusionThese preliminary results indicate the STMBT can provide reliable data when self‐administered using an online version of the task which has important implications for public health researchers. For our fully powered sample, we will provide summary of other measures.

A digital biomarker for remote self-assessment of Alzheimer's Diseases: development and validation.

Online data-collection provide an opportunity for Alzheimer's Disease research to collect large datasets crucial for understanding important public health concerns. However, the reliability of online tasks as compared to those administered in the lab is poorly examined. Our goal is to validate an online version of the short-term memory-binding task (STMBT), a potential digital biomarker sensitive to Alzheimer's Disease (Parra et al., 2010), to understand if data collected online in two environments, at-home and in the lab, is comparable. We created an online version of the STMBT task using Psytoolkit (Stoet 2010; Stoet 2017). Development involved piloting, group and user discussions to explore how such a novel tool could be best presented for self-assessment. Useful insights led to refinement of the online tool (i.e., instruction videos, images, and text). The validation stage involves test-retest reliability assessment of cognitively fit participants (aged >40 years) who complete the two conditions of this paradigm (i.e., shape only and binding). Task Environment (home and in the lab) and conditions (shape and binding) were fully counterbalanced. Measures of general cognitive abilities, anxiety and at-home environment were also taken. Recruitment is on-going, but preliminary data (n=10) has already proved informative. A repeated measures ANOVA looking at task-accuracy with factors of Environment (home vs. lab) and Condition (shape vs. binding) revealed no significant effects of Environment: F(1, 9) = 0.308, p = .591; Condition: F(1, 9) = 2.202, p = .172); or Interaction: F(1, 9) = 0.308, p = .591). For the shape condition, all participants performed near ceiling regardless of testing environment. In the binding condition, we observed good-to-excellent test-retest reliability between environments using single measures interclass correlation (ICC = 0.954, CI 0.83-0.99, (F(9, 9) = 39.62, p <.001). These preliminary results indicate the STMBT can provide reliable data when self-administered using an online version of the task which has important implications for public health researchers. For our fully powered sample, we will provide summary of other measures.

Rethinking fast and slow processing in autism.

Following the popularity of dual process models in social and cognitive psychology, there is major interest in the possibility that autism is associated with impaired "fast" intuitive thinking but enhanced "slow" or "rational" deliberative thinking. If correct, this has great potential to help understand various strengths and difficulties characteristic of autism. Previous empirical investigations of this phenomenon, however, are marred by concerns about the measurement of intuitive and deliberative processing, as well as broader problems in clinical psychological science (e.g., small underpowered studies, lack of replication). Making a step change, we conducted four large-scale studies to examine dual processing in autism, including a preregistered comparison of 200 autistic and nonautistic adults. Participants completed contemporary cognitive and self-report measures of intuitive and deliberative processing, as well as a psychometrically robust measure of general cognitive ability. Except for lower self-reported intuitive thinking, we found no unique contributions of autism to intuitive or deliberative thinking across all four studies, as evidenced by frequentist and Bayesian analyses. Overall, these studies indicate that intuitive and deliberative thinking is neither enhanced nor particularly impaired in relation to autism. We deliberate on the implications of these findings for theories of autism and future investigation of strengths and difficulties in autistic people. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Bilingualism and Healthy Aging: Onset Age of Bilingualism as a Predictor of Older Adult Theory of Mind

The ability to understand and speak more than one language (i.e., bilingualism) may protect against age-related cognitive deterioration (Abutalebi et al., 2015). While there is mounting evidence suggesting that bilingualism confers advantages in domain-general cognitive abilities in late adulthood (see Bialystok, 2017, for a review), few studies have investigated the influences of bilingualism on socio-cognitive abilities such as theory of mind (ToM) in the normal aging process. Thus, in this study, we examine how bilingualism factors (i.e., onset age of bilingualism, language balance, and diversity in language use) are associated with individual differences in ToM in healthy older adult bilinguals aged 58-79 (N=44). ToM abilities were assessed using the Theory-of-Mind Task Battery (Hutchins et al., 2008), where participants viewed vignettes and answered questions about the protagonists’ cognitive and affective mental states. All participants completed a self-report language background questionnaire and the Montreal Cognitive Assessment (MoCA) test as a measure of general cognitive ability. Results revealed that better ToM was negatively correlated with participants’ chronological age (r=-.43, p=.004) and the onset age of second-language acquisition (r=-.41, p=.006), but not language balance and diversity (ps>.40). Partial regression analyses showed that earlier onset age of bilingualism predicted better ToM performance (β=-.40, p=.009), even after controlling for age, education, and general cognitive ability. These findings suggest that bilingual language experience, particularly earlier exposure to a second language, may provide benefits to older adults in preserving their ability to understand others’ mental states, acting as a cognitive reserve against age-related declines in socio-cognitive functions.

Preliminary evidence for the Matrix Matching Test as a valid and reliable measure of general cognitive ability in adolescents

Introduction: In research, a simple measure of general cognitive ability is often required. One method is the Matrix Matching Test, a brief, free-to-use, language-free assessment of general cognitive ability or intelligence in adults, which taps both fluid and crystalized processes. We investigated its reliability and validity with adolescent participants. Method:The Matrix Matching Test was administered to 111 participants, aged 12 to 17 (46% female).Subsamples also completed two standard measures of cognitive ability: Vocabulary (crystalized) and Matrix Reasoning (fluid) tests from the Wechsler Intelligence Scale for Children IV (WISC-IV). Results: The Matrix Matching Test was found to have acceptable internal consistency and good retest reliability. Criterion validity was indicated by its ability to distinguish between psychosocially deprived participants living in foster care (n = 40) and controls, and by its positive correlation with grade point average. There were large positive correlations between the Matrix Matching Test and the standard measures of Vocabulary, and Matrix Reasoning, suggesting convergent validity. Conclusions: Our preliminary evidence suggests that The Matrix Matching Test is a reliable and valid measure of general cognitive ability for ages 12 to 17.

Executive functions and intelligence- are there genetic difference?

The first aim of this study was to explore the aetiology of phenotypic relationships between different measures of executive functions. The second objective was to examine sources of the covariation between different measures of executive functions and the measure of general cognitive ability. The study sample consisted of 468 twins (154 pairs of monozygotic twins and 80 pairs of dizygotic twins) of the same and different gender who grew up together. Executive functions were evaluated by the Wisconsin Card Sorting Test, the Trail Making Test – form B, and verbal fluency tests. Raven's Advanced Progressive Matrices were used as a measure of general cognitive ability. The study results suggest a primarily genetic origin of the mutual covariation of different executive measures and their covariation with the general cognitive ability construct. While the shared genetic variance primarily lies in the bases of similarity/unity of the used cognitive measures, their particularity/difference is determined by a specific unshared environment. The obtained result on the presence of a single general genetic factor, which can be singled out in the case of different executive measures, at least partially speaks in favor of the thesis about the unity of various executive measures and the existence of a common basic ability. Together with the specific unshared environment, the specific genetic influence speaks in favor of a difference between each of the individual measures.

Distinguishing patterns of impairment on inhibitory control and general cognitive ability among bipolar with and without psychosis, schizophrenia, and schizoaffective disorder

BackgroundDeficits in inhibitory control on a Stop Signal Task (SST) were previously observed to be of similar magnitude across schizophrenia, schizoaffective, and bipolar disorder with psychosis, despite variation in general cognitive ability. Understanding different patterns of performance on the SST may elucidate different pathways to the impaired inhibitory control each group displayed. Comparing nonpsychotic bipolar disorder to the psychosis groups on SST may also expand our understanding of the shared neurobiology of this illness spectrum. MethodsWe tested schizophrenia (n = 220), schizoaffective (n = 216), bipolar disorder with (n = 192) and without psychosis (n = 67), and 280 healthy comparison participants with a SST and the Brief Assessment of Cognition in Schizophrenia (BACS), a measure of general cognitive ability. ResultsAll patient groups had a similar degree of impaired inhibitory control over prepotent responses. However, bipolar groups differed from schizophrenia and schizoaffective groups in showing speeded responses and inhibition errors that were not accounted for by general cognitive ability. Schizophrenia and schizoaffective groups had a broader set of deficits on inhibition and greater general cognitive deficit, which fully accounted for the inhibition deficits. No differences were found between the clinically well-matched bipolar with and without psychosis groups, including for inhibitory control or general cognitive ability. ConclusionsWe conclude that 1) while impaired inhibitory control on a SST is of similar magnitude across the schizo-bipolar spectrum, including nonpsychotic bipolar, different mechanisms may underlie the impairments, and 2) history of psychosis in bipolar disorder does not differentially impact inhibitory behavioral control or general cognitive abilities.

The Relation Between Mini Mental State Examination and Multiple Measures of Executive Functioning

Given the necessity of executive functioning to perform day-to-day activities, the capacity of widely-used cognitive screening tools to detect potential executive dysfunctions could have important meanings for health care practices. Current research on this topic, however, is still scarce and controversial. The current study is the first of its kind to assess the association between a commonly used cognitive screening tool with multiple executive measures from two wildly used batteries of executive functioning tests. The Mini Mental State Examination (MMSE) along with the Delis Kaplan Executive Function System (DKEFS) and the Behavioural Assessment of the Dysexecutive Syndrome (BADS) were administered to 73 healthy adults aged 16-40 years (M=24.34, SD=6.53). Most of the relations between the MMSE total score and the executive measures were significant and in the moderate-to-strong range. The highest correlation of MMSE was with the BADS total profile score (r= .62, P&lt; .01). In a secondary analysis, among the MMSE domains, the Attention and Calculation domain had the highest relations with the executive measures. As a measure of general cognitive ability, the MMSE taps on various basic- and higher-level cognitive processes interconnected with the multi-dimensional and multi-level executive processing. Thus, empirical separation of executive measures and general cognitive indices is difficult. Using multiple measures of the executive functioning could be an effective strategy to better understanding the interconnections.

Longitudinal links between maternal factors and infant cognition: Moderation by infant sleep.

The current study examined the moderating role of infant sleep in the link between maternal factors (i.e., maternal education, depressive symptoms, sleep disturbance) and infant cognition. Data come from 95 African American parent-child dyads. At 3months of age, infant sleep was objectively measured using videosomnography and actigraphy, from which measures of sleep regulation and consolidation were calculated. Mothers also self-reported their level of education, depressive symptoms, and sleep quality. At 6months of age, infants completed cognitive assessments, including a measure of general cognitive ability and observed attention behavior. Findings revealed that infant sleep quality interacted with maternal education and sleep disturbances to predict cognition. Specifically, the link between maternal education and infants' attention behavior was significant and positive for infants with better regulated sleep, but not for infants with poorly regulated sleep. Similarly, the link between maternal sleep disturbance and infant cognition depended on infant sleep quality. For infants with poorer sleep consolidation, increased maternal sleep disturbance predicted poorer infant general cognitive ability. For infants with better sleep consolidation, maternal sleep disturbance was positively related to both general cognitive ability and attention behavior. These findings suggest that infant sleep quality moderates the impact of environmental factors on cognitive functioning.

Individual predictors of tactical planning performance in junior military officers

ABSTRACTThis exploratory study examined the influence of personal and psycholinguistic factors on tactical planning performance in a convenience sample of Australian Army personnel. Sixty male junior officers undertaking a tactical training course completed self-report measures of decision-making style, problem-solving appraisal, personality, and tactical planning expertise. A measure of general cognitive ability was sourced from participants’ military records. During the course, officers completed several tactical planning exercises that were assessed by course instructors, and an overall measure of tactical planning performance was derived. Psycholinguistic data was derived from participants’ thought processes elicited during an analogous planning exercise using a written think-aloud protocol. Automatic linear modeling analyses identified the combination of greater expertise and intuitive decision-making style, less spontaneous decision-making style and problem-solving confidence, younger age, and greater use of words relating to risk and past-focused concepts in their thought records, as significant predictors of better tactical planning, accounting for 55% of the variance in performance. Additionally, general cognitive ability, conscientiousness, and rational decision-making style shared moderate positive bivariate correlations with planning performance. This research has identified individual factors that contribute to tactical mission planning, along with future research avenues, which may inform the training of military commanders at the tactical level.

What We Know, Are Still Getting Wrong, and Have Yet to Learn about the Relationships among the SAT, Intelligence and Achievement.

Fifteen years ago, Frey and Detterman established that the SAT (and later, with Koenig, the ACT) was substantially correlated with measures of general cognitive ability and could be used as a proxy measure for intelligence (Frey and Detterman, 2004; Koenig, Frey, and Detterman, 2008). Since that finding, replicated many times and cited extensively in the literature, myths about the SAT, intelligence, and academic achievement continue to spread in popular domains, online, and in some academic administrators. This paper reviews the available evidence about the relationships among the SAT, intelligence, and academic achievement, dispels common myths about the SAT, and points to promising future directions for research in the prediction of academic achievement.

Not Just IQ: Patterning Predicts Preschoolers’ Math Knowledge Beyond Fluid Reasoning

ABSTRACTPreschoolers’ patterning skills are predictive of their concurrent and later math knowledge; however, it is unclear if patterning is only a proxy for general intelligence, or how it might support specific math skills. The current study examined the relation between 66 preschool children’s patterning skills and their general cognitive abilities, including fluid reasoning, working memory, and spatial skill. Further, the link between patterning and general math knowledge and specific math skills (i.e., numeracy and shape knowledge) was examined. Children’s patterning skills were significantly but only moderately linked to their performance on general cognitive ability measures (e.g., fluid reasoning). Further, beyond the effects of these general cognitive abilities, patterning significantly predicted both general math and numeracy knowledge, as well as verbal calculation and magnitude comparison. Thus, although patterning skills related to measures of general cognitive ability, patterning was a unique contributor to children’s general math and numeracy knowledge and specific math skills. Theories of math development and early math standards should thus be modified to emphasize the role of children’s patterning skills to their math development.

Childhood language development and later alcohol use behaviors

BackgroundStudies have shown a correlation between language abilities and alcohol use; however, results are inconsistent. A recent study using a discordant twin design showed an association between early child language development and later alcohol use behaviors; i.e., the twin with more advanced language abilities was more likely to try alcohol earlier in adolescence (Latvala et al., 2014). The authors suggested that this could result from better socialization of individuals with greater language abilities, which could lead to more opportunities for alcohol experimentation. The findings by Latvala et al. raise interesting questions, but the study has limitations, and replication is needed. MethodWe aimed to replicate and build upon these results utilizing 488 same sex twin pairs from the Colorado Longitudinal Twin Study, a longitudinal sample with quantitative measures of language abilities starting when the twins were 14 months old. ResultsWe found no significant correlations between a latent measure of child language abilities or measures of general cognitive ability at ages 14, 20, and 24 months and a latent alcohol use variable at ages 17 and 22 years. ConclusionOur results did not replicate the association between early language ability and later alcohol use reported by Latvala et al. Possible reasons for differing results across samples, including varying cultural norms as well as differences in educational attainment, peer influences, and novelty seeking, were discussed.

Adaptive functioning in children with neurofibromatosis type 1: relationship to cognition, behavior, and magnetic resonance imaging.

To characterize the adaptive behavior profile of children with neurofibromatosis type 1 (NF1) and determine its relationship to neuropsychological functioning and non-neoplastic T2-weighted hyperintense brain lesions on brain magnetic resonance imaging (MRI). In this cross-sectional study, we retrospectively reviewed neuropsychological reports from 104 children with NF1 (56 males, 48 females; mean age 10y 4mo; standard deviation [SD] 3y 4mo; range 3y 5mo-17y 6mo), and extracted data from a range of cognitive and behavioral measures, including the Adaptive Behavior Assessment System (ABAS). Brain MRI was retrospectively reviewed in 42 individuals. Adaptive Behavior Assessment System scores were continuously distributed and pathologically shifted by 0.79 to 1.26SD across Conceptual, Social, and Practical domains, and 46.5% of individuals had a composite score in the borderline or impaired range. Impairment in adaptive functioning was correlated with deficits in executive function (r=-9.543, p<0.001), externalizing problems (r=-0.366, p<0.001), and attention (r=-9.467, p=0.001). Cluster analysis revealed three distinct phenotypic subgroups, one of which exhibited normal cognitive ability, but impaired adaptive functioning, with persistent deficits in executive function, behavioral problems, and attention-deficit/hyperactivity disorder symptomatology. There was no relationship between ABAS scores and the number or location of unidentified bright objects. Adaptive functioning deficits are common among children with NF1 and are associated with impairment in other cognitive/behavioral domains, independent of general cognitive ability. Deficits in adaptive behavior are common in children with neurofibromatosis type 1 (NF1). Poor adaptive functioning is associated with impairments in executive function, externalizing behaviors, and attention, regardless of cognitive ability. The presence or location of unidentified bright objects do not predict adaptive behavior skills in children with NF1.

Cognitive impairment from early to middle adulthood in patients with affective and nonaffective psychotic disorders.

Cognitive impairment is a core feature of psychotic disorders, but the profile of impairment across adulthood, particularly in African-American populations, remains unclear. Using cross-sectional data from a case-control study of African-American adults with affective (n = 59) and nonaffective (n = 68) psychotic disorders, we examined cognitive functioning between early and middle adulthood (ages 20-60) on measures of general cognitive ability, language, abstract reasoning, processing speed, executive function, verbal memory, and working memory. Both affective and nonaffective psychosis patients showed substantial and widespread cognitive impairments. However, comparison of cognitive functioning between controls and psychosis groups throughout early (ages 20-40) and middle (ages 40-60) adulthood also revealed age-associated group differences. During early adulthood, the nonaffective psychosis group showed increasing impairments with age on measures of general cognitive ability and executive function, while the affective psychosis group showed increasing impairment on a measure of language ability. Impairments on other cognitive measures remained mostly stable, although decreasing impairments on measures of processing speed, memory and working memory were also observed. These findings suggest similarities, but also differences in the profile of cognitive dysfunction in adults with affective and nonaffective psychotic disorders. Both affective and nonaffective patients showed substantial and relatively stable impairments across adulthood. The nonaffective group also showed increasing impairments with age in general and executive functions, and the affective group showed an increasing impairment in verbal functions, possibly suggesting different underlying etiopathogenic mechanisms.

49 - LARGE-SCALE GWAS META-ANALYSIS AND MULTI-TRAIT ANALYSIS YIELDS DOZENS OF NOVEL LOCI AND NOVEL GENETIC CORRELATES FOR GENERAL COGNITIVE ABILITY

Background Neurocognitive deficits represent a critical component of many neuropsychiatric disorders and disease states that can affect health outcomes across the lifespan. Recently, a large (N~78,000) Genome-Wide Association Studie (GWAS) reported 18 genome-wide significant loci for cognitive performance as measured primarily by brief assessment (Sniekers et al. 2017, Nature Genetics, PMID: 28530673). At the same time, the Cognitive Genomics Consortium (COGENT), utilizing a PCA-derived measure of general cognitive ability, has reported two loci from its own collection of >35,000 subjects in 24 cohorts (Trampush et al. 2017, Molecular Psychiatry, PMID: 28093568). In the present report, we meta-analyze results of these two studies to perform the largest cognitive GWAS to date. To further boost power to detect loci associated with cognitive ability, we utilized a novel approach, Multi-Trait Analysis of GWAS (MTAG; Turley et al. 2017, biorxiv) to combine our results with related data from a large GWAS on educational attainment (Okbay et al. 2016, Nature, PMID: 27225129). Methods After accounting for overlapping cohorts, the combined dataset for cognitive ability included N=107,207 unique individuals. All subjects were of European ancestry and were drawn from the general population. Genotype data across all cohorts was imputed using the 1000 Genomes v3 reference panel, resulting in ~8 M high-quality SNPs. GWAS summary statistics were combined for meta-analysis using the sample-size weighted method in METAL, with gene-wise and pathway results examined using MAGMA. MTAG was applied to summary statistics from this dataset, combined with data from ~300,000 individuals of European ancestry assessed for educational attainment (years of schooling). Genetic overlap with other GWAS phenotypes was examined using the LD score regression (LDSC) method. Results Meta-analysis of the cognitive performance samples (N=107 K) yielded 28 genome-wide significant independent loci, 10 of which were novel. Moreover, 88 genes were implicated in the MAGMA analysis, which identified “neuron spine” as the most over-represented biological pathway. Inclusion of the educational attainment in MTAG analysis boosted the signal of our cognitive GWAS by ~500% and resulted in 71 genome-wide significant loci, of which 39 are novel to either phenotype. LDSC analyses of the meta-analytic and MTAG results revealed several novel genetic correlations, including a surprising strong correlation with parental age at death (rg~.4–.5). Discussion Sample sizes for GWAS of cognitive ability have finally attained critical mass to uncover increasing numbers of significant loci associated with brain function. Genetic overlap analysis reveals very strong correlations with psychiatric disorders, as well as with many health-relevant phenotypes. Based on the GWAS power curves that have been observed for other complex phenotypes, further increases in sample size will demonstrate substantially enhanced yield.

White matter microstructural development and cognitive ability in the first 2 years of life.

White matter (WM) integrity has been related to cognitive ability in adults and children, but it remains largely unknown how WM maturation in early life supports emergent cognition. The associations between tract-based measures of fractional anisotropy (FA) and axial and radial diffusivity (AD, RD) shortly after birth, at age 1, and at age 2 and cognitive measures at 1 and 2 years were investigated in 447 healthy infants. We found that generally higher FA and lower AD and RD across many WM tracts in the first year of life were associated with better performance on measures of general cognitive ability, motor, language, and visual reception skills at ages 1 and 2, suggesting an important role for the overall organization, myelination, and microstructural properties of fiber pathways in emergent cognition. RD in particular was consistently related to ability, and protracted development of RD from ages 1 to 2 years in several tracts was associated with higher cognitive scores and better language performance, suggesting prolonged plasticity may confer cognitive benefits during the second year of life. However, we also found that cognition at age 2 was weakly associated with WM properties across infancy in comparison to child and demographic factors including gestational age and maternal education. Our findings suggest that early postnatal WM integrity across the brain is important for infant cognition, though its role in cognitive development should be considered alongside child and demographic factors.

Musical Competence is Predicted by Music Training, Cognitive Abilities, and Personality

Individuals differ in musical competence, which we defined as the ability to perceive, remember, and discriminate sequences of tones or beats. We asked whether such differences could be explained by variables other than music training, including socioeconomic status (SES), short-term memory, general cognitive ability, and personality. In a sample of undergraduates, musical competence had positive simple associations with duration of music training, SES, short-term memory, general cognitive ability, and openness-to-experience. When these predictors were considered jointly, musical competence had positive partial associations with music training, general cognitive ability, and openness. Nevertheless, moderation analyses revealed that the partial association between musical competence and music training was evident only among participants who scored below the mean on our measure of general cognitive ability. Moreover, general cognitive ability and openness had indirect associations with musical competence by predicting music training, which in turn predicted musical competence. Musical competence appears to be the result of multiple factors, including but not limited to music training.