Objective: Cognitive disengagement syndrome (CDS), formerly known as sluggish cognitive tempo, is characterized by hypoactivity or slowed behavior, mental fogginess or confusion, excessive sleepiness, and daydreaming. CDS and the predominantly inattentive (IN) presentation of attentiondeficit/hyperactivity disorder (ADHD) are frequently co-occurring albeit separable constructs, each associated with unique constellations of functional impairments. The current study aims to identify their shared and divergent neurobiological correlates. Method: A total of 181 adolescents (mean age =13.9 years, SD = 2.2 years) were recruited from the Colorado Learning Disabilities Research Center twin study. Relationships between attentional symptom dimensions (CDS and IN) and brain volume were examined, controlling for age, sex, and average cortical volume. Procedures were repeated in an outside sample of 292 adolescents (mean age = 16.8 years, SD = 1.4 years) using a 2-item measure of CDS. Results: Higher levels of CDS symptoms were associated with reduced volume within the left ventral parietal, temporo-parietal, and temporal regions, regions that fall within the ventral attention network. CDS and IN symptoms were significantly associated with gray matter volume in portions of the dorsal attention and default mode networks in opposite directions. Higher levels of CDS symptoms were associated with reduced volume in the left superior and inferior parietal lobules and left frontal portions of the default mode network, whereas IN symptoms were positively correlated with volume in these areas. Several findings were consistent in the outside sample. Conclusion: Results from the current study provide novel insights into the neurobiological basis of CDS. They suggest that both CDS and IN symptoms are associated with alterations in brain systems that exert top-down attentional control, though likely for differing reasons. The current study enhances understanding of adolescent attentional deficits. Plain language summary: This study used brain magnetic resonance imaging (MRI) scans of 2 samples of adolescents with a total of 473 participants to explore how symptoms of two attentional constructs-attention-deficit/hyperactivity disorder (ADHD) inattention and cognitive disengagement syndrome (CDS)-relate to brain structure. The authors found that these symptoms are linked to differences in brain volume in attention-related areas, but in opposite ways: inattention was associated with greater volume, while cognitive disengagement was associated with reduced volume in the same regions. These findings suggest that although these attention difficulties often occur together, they may have different underlying brain mechanisms.

PurposeData sets are often combined to increase power to better understand the development of reading. However, there is difficulty in measure alignment, resulting in harmonization issues for analysis and interpretation. This study uses Rosetta, which allows for the concurrent analysis of related but incompletely overlapping data, to combine the Western Reserve Reading Project (WRRP) and Colorado Longitudinal Twin Study (LTS) to analyze the development of reading.MethodReading comprehension was assessed across grades 1-5 and 9 (N = 1602; male = 49%), and across three reading comprehension measures in the WRRP sample (Mz = 135 pairs, Dz = 224 pairs) and the LTS sample (Mz = 205 pairs, Dz = 237 pairs). The primary language was English.ResultsResults demonstrate expected heritability, shared environmental, and nonshared environmental estimates, but with decreased standard error estimates. Rosetta is a useful tool for developing more robust results on the development of reading and other complex traits.

Early reading skills are critical for later academic outcomes, which include mathematics. Yet, these relations may vary by a child's ability level. This study examined how early reading skills relate to different levels of third-grade mathematics. The samples included 105 same-sex twin pairs (210 individuals, 57% female, 43% male) from the ongoing longitudinal Western Reserve Reading and Math Projects, assessed at kindergarten (M = 6.18, SD = 0.44) and third grade (M = 9.07, SD = 0.49). Kindergarten reading measures consisted of the Letter Identification task from the Woodcock Reading Mastery Test-Revised Normative Update, the Deletion subtests from Phonological Awareness Test, and the Letter Naming Fluency task from the Dynamic Indicators of Basic Early Literacy Skills; third-grade math measures included Calculation, Fluency, Applied Problem, and Quantitative Concepts subtests of Woodcock-Johnson III Tests of Achievement. Both linear and quantile regressions were conducted using reading measures as predictors and math measures as the dependent variables. Linear regressions indicated that the Deletion Summary Score was a unique predictor of Applied Problems, and Letter Naming Fluency was a significant and unique predictor of Calculation Fluency and Quantitative Concepts. Quantile regressions provided a more thorough analysis of these relations. It was found that Letter Naming Fluency was significantly associated with Calculation, Calculation Fluency, and Quantitative Concepts at the lower level. The Deletion Summary Score had relatively stable relations with Applied Problems across all levels. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Quantile-sensitive methodologies have gained traction in recent years, with researchers leveraging these approaches to conduct more in-depth analyses than are capable with traditional mean-centered approaches. These approaches have been used widely for regression and correlational-based approaches, finding evidence of heterogeneous effects based on the portion of the distribution analyzed. However, the methodologies for conducting quantile-sensitive work using more complex designs are limited, and extending this work into structural equation modeling (SEM) approaches was our primary aim. We conducted our study using a series of Monte-Carlo simulations, each representing data where SEM models with varying structures and values fit best depending on the portion of the distributions analyzed. A novel distance-based method (DSW), was developed and applied to the simulated datasets, observing its average and range of effectiveness to detect the heterogeneous SEM models and effects that underlie the datasets throughout their distributions. Two other methods were also tested, but have known limitations and instead were meant to serve as references for this approach, highlighting the advantages of the DSW method and the ways it addressed their limitations. Results found that the DSW approach was highly effective in detecting heterogeneous findings in regression models, latent growth curves, and factor-analytic models (both nested and non-nested models), accurately detecting the modeled differences in varying latent factor structures and other effect sizes and significantly outperforming the other approaches. Limitations and future directions for this work are discussed, highlighting the new areas of work this method opens up and its potential areas of extension.

This paper reviews three studies investigating the relationship between brain regions involved in executive control and those involved in reading comprehension in typically-developing teens. In the first study, three regions of posterior left lateral prefrontal cortex (i.e., precentral gyrus, inferior frontal junction, inferior frontal gyrus) were consistently activated across three task domains: reading comprehension, numerical estimation, and executive processes in working memory, suggesting these regions exert domain-general executive control. In a second study, brain activity in the precentral gyrus during reading comprehension was found to be associated with individual differences in reading achievement. A subsequent investigation indicated that while all three prefrontal regions exhibit greater connectivity to the angular gyrus during reading comprehension compared to symbol identification, each also exhibits unique connectivity to distinct posterior regions implicated in reading processes. Hence, reading difficulties during adolescence may arise, in part, from difficulties in executive control over processing in language-related brain regions.

It has become clear in recent years that reading, while relying on domain-specific language processing regions, also involves regions that implement executive processes more broadly. Such executive control is generally considered to be implemented by prefrontal regions, which exert control via connectivity that allows them to modulate processing in target brain regions. The present study examined whether three previously identified and distinct executive control regions in the pFC [Wang, K., Banich, M. T., Reineberg, A. E., Leopold, D. R., Willcutt, E. G., Cutting, L. E., et al. Left posterior prefrontal regions support domain-general executive processes needed for both reading and math. Journal of Neuropsychology, 14, 467-495, 2020] show similar patterns of functional connectivity (FC) during a reading comprehension task as compared with a symbol identification condition. Our FC results in a sample of adolescents (n = 120) suggest all three regions commonly show associations with activity in "classic" left hemisphere reading areas, including the angular and supramarginal gyri, yet each exhibits differential connectivity as well. In particular, precentral regions show differential FC to parietal portions of the dorsal language stream, the inferior frontal junction shows differential FC to middle temporal regions of the right hemisphere and other regions involved in semantic processing, and portions of the inferior frontal gyrus show differential FC to an extensive set of right hemisphere prefrontal regions. These results suggest that prefrontal control over language-related regions occurs in a coordinated yet discrete manner.

Introduction To investigate the effects of different strategies and cognitive load we explored brain hemodynamic responses associated with the use of different strategies to solve subtraction of fractions. We focused on those born extremely preterm (EPT; <28 weeks’ gestation) as they are known to have cognitive challenges and struggle with mathematics. We also included a group of full-term (FT) peers for comparison. Methods Functional MRI was acquired while the participants mentally solved fraction equations using either a strategy based on improper or mixed fractions. Different fraction item types were given, which affected respective required cognitive loads per strategy. Diffusion and T1-weighted structural images were also acquired. Results The EPT and FT groups differed in terms of task-related hemodynamic responses. Functional group differences were greatest when strategies were applied to item types that result in high cognitive load. Other findings showed reduced white and grey matter volume and reduced white matter connectivity in widespread areas in the EPT group compared to the FT group. Conclusion The understanding of function and structure presented here may help inform pedagogical practices by allowing for tailoring of mathematical education through identifying suitable strategy adoption that depends on item type, to circumvent weaknesses in cognitive skills.

Substantial evidence has suggested that reading and math are supported by executive processes (EP). However, to date little is known about which portion of the neural system underpinning domain-general executive skills works to support reading and math. In this study, we aimed to answer this question using fMRI via two complementary approaches. First, imaging data were acquired whilst a sample of 231 adolescents performed each of three separate tasks designed to assess reading comprehension, numerical magnitude estimation, and EP in working memory (WM), respectively. With careful task designs and conjunction analyses, we were able to isolate cross-domain brain activity specifically related to EP, as opposed to lower-level domain-general processes (e.g., visual processing). Second, the meta-analytic tool Neurosynth was used to independently identify brain regions involved reading, math, and EP. Using a combination of forward and reverse statistical inference and conjunction analyses, we again isolated brain regions specifically supporting domain-general EP. Results from both approaches yielded overlapping activation for reading, math, and EP in the left ventrolateral prefrontal cortex, left inferior frontal junction, and left precentral gyrus. This pattern suggests that posterior regions of the prefrontal cortex, rather than more central regions such as mid-DLPFC, play a leading role in supporting domain-general EP utilized by both reading and math.

Background The number line task assesses the ability to estimate numerical magnitudes. People vary greatly in this ability, and this variability has been previously associated with mathematical skills. However, the sources of individual differences in number line estimation and its association with mathematics are not fully understood. Aims This large-scale genetically sensitive study uses a twin design to estimate the magnitude of the effects of genes and environments on: (1) individual variation in number line estimation and (2) the covariation of number line estimation with mathematics. Samples We used over 3,000 8- to 16-year-old twins from the United States, Canada, the United Kingdom, and Russia, and a sample of 1,456 8- to 18-year-old singleton Russian students. Methods Twins were assessed on: (1) estimation of numerical magnitudes using a number line task and (2) two mathematics components: fluency and problem-solving. Results Results suggest that environments largely drive individual differences in number line estimation. Both genes and environments contribute to different extents to the number line estimation and mathematics correlation, depending on the sample and mathematics component. Conclusions Taken together, the results suggest that in more heterogeneous school settings, environments may be more important in driving variation in number line estimation and its association with mathematics, whereas in more homogeneous school settings, genetic effects drive the covariation between number line estimation and mathematics. These results are discussed in the light of development and educational settings.

To better characterize the neural correlates of the full spectrum of reading ability, this fMRI study examined how variations in reading ability correlate with task-based brain activity during reading among a large community sample of adolescents (N = 234). In addition, complimentary approaches taking advantage of empirical as well as independent meta-analytic information were employed to isolate neural substrates of domain-general executive processes that are predictive of reading ability. Age-related differences in brain activity were also examined. Better reading was associated with increased activation in left anterior and inferior temporal regions and parts of orbitofrontal cortex, along with reduced activation in the thalamus and left frontal eye field (FEF). Converging evidence suggests that FEF activity corresponds to executive processes during reading. In contrast, activity in temporal regions is likely to reflect cognitive processes specific to reading. Older adolescents also demonstrated increased activation in an orbitofrontal region that overlaps with the aforementioned age-independent, reading-related regions, along with reduced activity in parietal and occipital regions. These results suggest that comparedto poor readers, proficient readers benefit from efficient reading-specific processes and require less executive effort, implemented via the FEF, during a reading comprehension task.

Music education is associated with increased speech perception abilities and anecdotal evidence suggests musical training is also beneficial for performance in a variety of academic areas. In spite of this positive association, very little empirical evidence exists to support this claim except for a few studies linking musical training to improvements in verbal tasks. We evaluated the relationships between specific aspects of musical training/ability and scores on a series of standardized reading assessments in a sample of twins. There was a significant and positive relationship between self-reported sight-reading ability for sheet music and performance on passage comprehension - a standardized reading measure that relies on decoding and working memory. This effect was specific to sight reading ability, as other musical variables, such as number of years of practice or music theory, were not related to performance on this reading measure. Surprisingly, the verbal working memory ability we tested did not mediate this relationship. To determine whether there is a genetic component to these skills, we compared these relationships in pairs of monozygotic twins compared to dizygotic twins. Interestingly, intraclass correlations (ICCs) for sight reading and passage comprehension were both higher in monozygotic twins compared to dizygotic twins, though this effect was larger for passage comprehension than for sight reading. These results together suggest a familial and potentially partially shared inherited mechanism for success in both musical sight-reading ability and passage comprehension.

Analyses have suggested math anxiety is a multidimensional construct. However, previous behavioral genetic work examining math anxiety was unidimensional. Thus, the purpose of the present study was to examine different approaches for specifying behavioral genetic models of math anxiety as a multidimensional construct. Three models were compared: a unidimensional model, a three dimension multidimensional model, and a bi-factor model, which partitioned variance into one common factor shared across three dimensions of math anxiety and examined residual variance in each dimension. The best fitting model was a bi-factor AE model, which suggested moderate heritability of general math anxiety and that each dimension of math anxiety had unique etiological influences not accounted for by shared variance with the general math anxiety factor. Thus, while there was evidence of shared etiology, there was also evidence of some etiological distinction across dimensions of math anxiety. The results demonstrate the importance of taking into account the dimensionality of the scale when interpreting similarity across twins.

Behavioral genetic approaches, such as comparing monozygotic and dizygotic twins, are often used to evaluate the extent to which variations in human abilities are the result of genetic (heritable), shared environmental, and non-shared environmental factors. We conducted a meta-analysis on the twin study literature-comparing monozygotic and dizygotic twins-to provide clarity and a general consensus regarding the extent to which genetic and environmental factors contribute to variation in spatial ability. Consistent with previous work, we found that spatial ability is largely heritable (meta-analytic a (a) over bar = .61; 95% CI [.55, .66]), with non-shared environmental factors having a substantial impact (meta-analytic (e) over bar.= .43; 95% CI [.38, .49]), and shared environmental factors having very little impact (meta-analytic (c) over bar.= .07; 95% CI [.05, .10]). Moderator analyses were performed to establish if spatial ability type, sex, or age impacted the explanatory power of genetics or environmental factors. These effects did not differ significantly by sex or spatial ability type. However, the influence of shared environments did significantly differ depending on age. This result was driven by the youngest age group (ages 4-15) demonstrating relatively high amounts of shared environmental influence (c = .15, 95% CI [.10, .20]) compared with the other age groups (cs = .00-.07).

Emerging research has identified sluggish cognitive tempo (SCT) as a construct separate from ADHD predominately inattentive presentation. The present study explores the longitudinal stability of SCT over a period of 7 years, specifically the independent effects of SCT on behavioural and academic outcomes concurrently over a 3-year period. A sample of 639 twins, aged 6–12 years, participating in the Western Reserve Reading and Math Project (WRRMP) were assessed at seven annual home visits. The WRRMP sample is an unselected sample of twins representative of the general population of typically developing school-age children. The current investigation will focus on parent and teacher reports which assess attention deficit hyperactive/impulsive disorder (ADHD) and standardized achievement measures which assess academic outcomes. Over periods longer than 1 or 2 years, SCT does not display good longitudinal stability ( r < .60). SCT also does not have consistent significant independent effects on academic outcomes once the effects of ADHD were controlled for. Over a 7-year period, SCT does not demonstrate consistent longitudinal stability. SCT significantly predicts social problems, internalizing behaviours, and anxious/depressive behaviours after the effects of ADHD are controlled for. SCT has no significant independent effects on cognitive or educational outcomes after the effects of inattentive ADHD are controlled for.

The debate about how to characterize performance on the number line estimation (NLE) task has yielded a diverse set of accuracy measures. These accuracy measures include characterizing performance by deviation from the correct score with percent absolute error (PAE), modeling the shape of responses via the logarithmic-to-linear shift, and modeling the strategy use via the cyclical power model (one and two cycle). In the present study, accuracy on a symbolic NLE task was examined using phenotypic and quantitative genetic analyses of all four measurements. Data were collected from a same-sex twin sample at ages 12 and 15 (N = 150 pairs) as part of the Western Reserve Reading and Math Project. Linear mixed-effect models were used to compare how well the four NLE accuracy measures predicted math achievement, as measured by the Woodcock Johnson-III Fluency, Calculation, and Applied Problems subtests, after cognitive ability was controlled. NLE accuracy measures were not related to Fluency or Calculation after cognitive ability was controlled, but all NLE accuracy measures were related to Applied Problems at 12 and 15 years old. Although theories about what the NLE task measures have been contested in the literature, the relationship between NLE accuracy and achievement did not differ regardless of the type of accuracy measure used. In addition, the estimates for genetic and environmental influences were proportionately similar across the NLE accuracy measures. Overall, all proposed measures of accuracy in the present sample appear appropriate for prediction of math achievement in adolescents.

Approximate number sense (ANS), the ability to rapidly and accurately compare quantities presented non-symbolically, has been proposed as a precursor to mathematics skills. Earlier work reported low heritability of approximate number sense, which was interpreted as evidence that approximate number sense acts as a fitness trait. However, viewing ANS as a fitness trait is discordant with findings suggesting that individual differences in approximate number sense acuity correlate with mathematical performance, a trait with moderate genetic effects. Importantly, the shared etiology of approximate number sense, mathematics, and general cognitive ability has remained unexamined. Thus, the etiology of approximate number sense and its overlap with math and general cognitive ability was assessed in the current study with two independent twin samples (N = 451 pairs). Results suggested that ANS acuity had moderate but significant additive genetic influences. ANS also had overlap with generalist genetic mechanisms accounting for variance and covariance in mathematics and general cognitive ability. Furthermore, ANS may have genetic factors unique to covariance with mathematics beyond overlap with general cognitive ability. Evidence across both samples was consistent with the proposal that the etiology of approximate number sense functions similar to that of mathematics and general cognitive skills.

Individual differences in number sense correlate with mathematical ability and performance, although the presence and strength of this relationship differs across studies. Inconsistencies in the literature may stem from heterogeneity of number sense and mathematical ability constructs. Sample characteristics may also play a role as changes in the relationship between number sense and mathematics may differ across development and cultural contexts. In this study, 4,984 16-year-old students were assessed on estimation ability, one aspect of number sense. Estimation was measured using 2 different tasks: number line and dot-comparison. Using cognitive and achievement data previously collected from these students at ages 7, 9, 10, 12, and 14, the study explored for which of the measures and when in development these links are observed, and how strong these links are and how much these links are moderated by other cognitive abilities. The 2 number sense measures correlated modestly with each other (r = .22), but moderately with mathematics at age 16. Both measures were also associated with earlier mathematics; but this association was uneven across development and was moderated by other cognitive abilities. (PsycINFO Database Record