Changes in frontal-parietal activation and math skills performance following adaptive number sense training: preliminary results from a pilot study

Verbal but not visual-spatial working memory contributes to complex arithmetic calculation

The contribution of working memory to mathematics has been extensively studied. It has been proposed that verbal working memory (VWM) and visual-spatial working memory (VSWM) have distinct contributions, but results have been inconclusive. Here, we hypothesized that VWM and VSWM contribute differentially to separate sub-domains of mathematics. To test this hypothesis, we enrolled 199 primary school students and measured their VWM and VSWM with number/letter/matrix backward span tasks, and tested mathematics performance with simple subtraction, complex subtraction, multi-step calculation and number series completion, while controlling for several aspects of cognition. We found that while letter backward span had a significant contribution to complex subtraction, multi-step computation and number series completion, number backward span only had a significant contribution to multi-step computation, and matrix span had no effect on any math task. These results suggest that only VWM associated with complex mathematics, which might reflect verbal rehearsal. In contrast, VSWM does not appear to associated with mathematics.

The first year in formal schooling improves working memory and academic abilities

Neurocognition and academic abilities during the period of 4 and 7 years of age are impacted by both the transition from kindergarten to primary school and age-related developmental processes. Here, we used a school cut-off design to tease apart the impact of formal schooling from age, on working memory (WM) function, vocabulary, and numeracy scores. We compared two groups of children with similar age, across two years: first-graders (FG), who were enrolled into primary school the year that they became eligible and kindergarteners (KG), who were deferred school entry until the following year. All children completed a change detection task while brain activation was recorded using portable functional near-infrared spectroscopy, a vocabulary assessment, and a numeracy screener. Our results revealed that FG children showed greater improvement in WM performance and greater engagement of a left-lateralized fronto-parietal network compared to KG children. Further, they also showed higher gains in vocabulary and non-symbolic numeracy scores. This improvement in vocabulary and non-symbolic numeracy scores following a year in primary school was predicted by WM function. Our findings contribute to a growing body of literature examining neurocognitive and academic benefits conferred to children following exposure to formal schooling.

Systematic Fusion of Multi-Source Cognitive Networks With Graph Learning - A Study on Fronto-Parietal Network

Cognitive tasks induce fluctuations in the functional connectivity between brain regions which constitute cognitive networks in the human brain. Although several cognitive networks have been identified, consensus still cannot be achieved on the precise borders and distribution of involved brain regions for each network, due to the multifarious use of diverse brain atlases in different studies. To address the problem, the current study proposed a novel approach to generate a fused cognitive network with the optimal performance in discriminating cognitive states by using graph learning, following the synthesization of one cognitive network defined by different brain atlases, and the construction of a hierarchical framework comprised of one main version and other supplementary versions of the specific cognitive network. As a result, the proposed method demonstrated better results compared with other machine learning methods for recognizing cognitive states, which was revealed by analyzing an fMRI dataset related to the mental arithmetic task. Our findings suggest that the fused cognitive network provides the potential to develop new mind decoding approaches.

Training causes activation increase in temporo-parietal and parietal regions in children with mathematical disabilities

While arithmetic training reduces fronto-temporo-parietal activation related to domain-general processes in typically developing (TD) children, we know very little about the training-related neurocognitive changes in children with mathematical disabilities (MD), who seek evidenced-based educational interventions. In a within-participant design, a group of 20 children (age range = 10-15 years old) with MD underwent 2 weeks of arithmetic training. Brain activation was measured using functional near-infrared spectroscopy (fNIRS) before and after training to assess training-related changes. Two weeks of training led to both behavioral and brain changes. Training-specific change for trained versus untrained (control) simple multiplication solving was observed as activation increase in the bilateral temporo-parietal region including angular gyrus and middle temporal gyrus. Training-specific change for trained versus untrained (control) complex multiplication solving was observed as activation increase in the bilateral parietal region including intraparietal sulcus, superior parietal lobule, and supramarginal gyrus. Unlike the findings of a similar study in TD children, 2 weeks of multiplication training led to brain activation increase in the fronto-parietal network in children with MD. Interestingly, these brain activation differences between the current findings and a recent similar study in TD children underlie a rather similar behavioral improvement as regards response time and accuracy after 2 weeks of training. This finding provides valuable insights into underlying mechanisms of mathematics learning in special samples and suggests that the findings in TD children may not be readily generalized to children with MD.

ADGRL3, FGF1 and DRD4: Linkage and Association with Working Memory and Perceptual Organization Candidate Endophenotypes in ADHD

Attention deficit hyperactivity disorder (ADHD) is a highly heritable neurobehavioral disorder that affects children worldwide, with detrimental long-term consequences in affected individuals. ADHD-affected patients display visual-motor and visuospatial abilities and skills that depart from those exhibited by non-affected individuals and struggle with perceptual organization, which might partially explain impulsive responses. Endophenotypes (quantifiable or dimensional constructs that are closely related to the root cause of the disease) might provide a more powerful and objective framework for dissecting the underlying neurobiology of ADHD than that of categories offered by the syndromic classification. In here, we explore the potential presence of the linkage and association of single-nucleotide polymorphisms (SNPs), harbored in genes implicated in the etiology of ADHD (ADGRL3, DRD4, and FGF1), with cognitive endophenotypes related to working memory and perceptual organization in 113 nuclear families. These families were ascertained from a geographical area of the Caribbean coast, in the north of Colombia, where the community is characterized by its ethnic diversity and differential gene pool. We found a significant association and linkage of markers ADGRL3-rs1565902, DRD4-rs916457 and FGF1-rs2282794 to neuropsychological tasks outlining working memory and perceptual organization such as performance in the digits forward and backward, arithmetic, similarities, the completion of figures and the assembly of objects. Our results provide strong support to understand ADHD as a combination of working memory and perceptual organization deficits and highlight the importance of the genetic background shaping the neurobiology, clinical complexity, and physiopathology of ADHD. Further, this study supplements new information regarding an ethnically diverse community with a vast African American contribution, where ADHD studies are scarce.

Training-Induced Neural Plasticity in Youth: A Systematic Review of Structural and Functional MRI Studies

Experience-dependent neural plasticity is high in the developing brain, presenting a unique window of opportunity for training. To optimize existing training programs and develop new interventions, it is important to understand what processes take place in the developing brain during training. Here, we systematically review MRI-based evidence of training-induced neural plasticity in children and adolescents. A total of 71 articles were included in the review. Significant changes in brain activation, structure, microstructure, and structural and functional connectivity were reported with different types of trainings in the majority (87%) of the studies. Significant correlation of performance improvement with neural changes was reported in 51% of the studies. Yet, only 48% of the studies had a control condition. Overall, the review supports the hypothesized neural changes with training while at the same time charting empirical and methodological desiderata for future research.

Effectiveness of Computerized Cognitive Training Programs (CCTP) with Game-like Features in Children with or without Neuropsychological Disorders: a Meta-Analytic Investigation

Computerized cognitive training programs (CCTP) are based on the assumption that cognitive abilities may be boosted by repetitively performing challenging tasks. The integration of game-like features in these programs, associated with the goal of amusing or rewarding participants, may contribute to generate cognitive benefits. Indeed, reinforcement contingencies have been reported to produce positive effects on performance and motivation, especially in children. This meta-analysis was aimed at providing a quantitative summary of the effectiveness of CCTP with game-like features in school-aged children with typical and atypical development. A total of 24 studies, with the cognitive and behavioral outcome data of 1547 participants, were selected for inclusion in the meta-analysis. Subgroup analyses were performed to identify the sources of the observed methodological heterogeneity. A robust variance estimation model, after removal of study outliers, yielded a small-to-moderate significant effect size. Final results pointed out smaller but more precise estimate effect sizes according to methodological aspects related to cognitive domain of outcomes, standardization of measures and type of control applied. Alongside supporting the use of CCTP for rehabilitating cognitive functions, the present results shed light on how different methodological choices are able to shape research findings in the field of children's cognitive rehabilitation.

Home-based cognitive training in pediatric patients with acquired brain injury: preliminary results on efficacy of a randomized clinical trial

Cognitive rehabilitation may compensate for cognitive deficits of children with acquired brain injury (ABI), capitalizing on the use-dependent plasticity of a developing brain. Remote computerized cognitive training (CCT) may be delivered to patients in ecological settings, ensuring rehabilitation continuity. This work evaluated cognitive and psychological adjustment outcomes of an 8-week multi-domain, home-based CCT (Lumosity Cognitive Training) in a sample of patients with ABI aged 11–16 years. Two groups of patients were engaged in five CCT sessions per week for eight weeks (40 sessions). According to a stepped-wedge research design, one group (Training-first Group) started the CCT immediately, whereas the other group (Waiting-first Group) started the CCT after a comparable time of waiting list. Changes after the training and after the waiting period were compared in the two groups. Both groups improved in visual-spatial working memory more after the training than after the waiting-list period. The Training-first group improved also in arithmetic calculation speed. Findings indicate that a multi-domain CCT can produce benefits in visual-spatial working memory, probably because, in accordance with previous research, computer games heavily tax visuo-spatial abilities. This suggests that the prolonged stimulation of the same cognitive ability may generate the greatest benefits in children with ABI.

Brain Training in Children and Adolescents: Is It Scientifically Valid?

Background: Brain training products are becoming increasingly popular for children and adolescents. Despite the marketing aimed at their use in the general population, these products may provide more benefits for specific neurologically impaired populations. A review of Brain Training (BT) products analyzing their efficacy while considering the methodological limitations of supporting research is required for practical applications. Method: searches were made of the PubMed database (until March 2017) for studies including: (1) empirical data on the use of brain training for children or adolescents and any effects on near transfer (NT) and/or far transfer (FT) and/or neuroplasticity, (2) use of brain training for cognitive training purposes, (3) commercially available training applications, (4) computer-based programs for children developed since the 1990s, and (5) relevant printed and peer-reviewed material. Results: Database searches yielded a total of 16,402 references, of which 70 met the inclusion criteria for the review. We classified programs in terms of neuroplasticity, near and far transfer, and long-term effects and their applied methodology. Regarding efficacy, only 10 studies (14.2%) have been found that support neuroplasticity, and the majority of brain training platforms claimed to be based on such concepts without providing any supporting scientific data. Thirty-six studies (51.4%) have shown far transfer (7 of them are non-independent) and only 11 (15.7%) maintained far transfer at follow-up. Considering the methodology, 40 studies (68.2%) were not randomized and controlled; for those randomized, only 9 studies (12.9%) were double-blind, and only 13 studies (18.6%) included active controls in their trials. Conclusion: Overall, few independent studies have found far transfer and long-term effects. The majority of independent results found only near transfer. There is a lack of double-blind randomized trials which include an active control group as well as a passive control to properly control for contaminant variables. Based on our results, Brain Training Programs as commercially available products are not as effective as first expected or as they promise in their advertisements.

Arithmetic in the developing brain: A review of brain imaging studies

Brain imaging studies on academic achievement offer an exciting window on experience-dependent cortical plasticity, as they allow us to understand how developing brains change when children acquire culturally transmitted skills. This contribution focuses on the learning of arithmetic, which is quintessential to mathematical development. The nascent body of brain imaging studies reveals that arithmetic recruits a large set of interconnected areas, including prefrontal, posterior parietal, occipito-temporal and hippocampal areas. This network undergoes developmental changes in its function, connectivity and structure, which are not yet fully understood. This network only partially overlaps with what has been found in adults, and clear differences are observed in the recruitment of the hippocampus, which are related to the development of arithmetic fact retrieval. Despite these emerging trends, the literature remains scattered, particularly in the context of atypical development. Acknowledging the distributed nature of the arithmetic network, future studies should focus on connectivity and analytic approaches that investigate patterns of brain activity, coupled with a careful design of the arithmetic tasks and assessments of arithmetic strategies. Such studies will produce a more comprehensive understanding of how the arithmetical brain unfolds, how it changes over time, and how it is impaired in atypical development.

Addressing the Math-Practice Gap in Elementary School: Are Tablets a Feasible Tool for Informal Math Practice?

Students rarely practice math outside of school requirements, which we refer to as the “math-practice gap”. This gap might be the reason why students struggle with math, making it urgent to develop means by which to address it. In the current paper, we propose that math apps offer a viable solution to the math-practice gap: Online apps can provide access to a large number of problems, tied to immediate feedback, and delivered in an engaging way. To substantiate this conversation, we looked at whether tablets are sufficiently engaging to motivate children’s informal math practice. Our approach was to partner with education agencies via a community-based participatory research design. The three participating education agencies serve elementary-school students from low-SES communities, allowing us to look at tablet use by children who are unlikely to have extensive access to online math enrichment programs. At the same time, the agencies differed in several structural details, including whether our intervention took place during school time, after school, or during the summer. This allowed us to shed light on tablet feasibility under different organizational constraints. Our findings show that tablet-based math practice is engaging for young children, independent of the setting, the student’s age, or the math concept that was tackled. At the same time, we found that student engagement was a function of the presence of caring adults to facilitate their online math practice.

The processing of number scales beyond whole numbers in development: Dissociations in arithmetic in Turner's syndrome

The arithmetical skills in two children with Turner's syndrome (TS), each the focus of a case study, were analysed in whole numbers and other number scales that have not been systematically explored previously, fractions, decimals, percentages, and negative numbers. The intention was to identify the fractionation of arithmetical skills. The two girls with TS showed dissociations of arithmetical skill in the calculation system of whole numbers that support its modular organization. Fractionation of skills was observed in some components of the other number scales, suggesting an analogous organization within these scales. The operational specificity of impairment within number scales but not others argued against a unitary arithmetical system but rather for autonomous operational scales within distinct number scales. A general model of arithmetic is proposed.

Using cognitive training studies to unravel the mechanisms by which the approximate number system supports symbolic math ability

A picture is emerging that preverbal nonsymbolic numerical representations derived from the approximate number system (ANS) play an important role in mathematical development and sustained mathematical thinking. Functional imaging studies are revealing developmental trends in how the brain represents number. We propose that combining behavioral and neuroimaging techniques with cognitive training approaches will help identify the fundamental relationship between the ANS and symbolic mathematics. Understanding this relationship should ultimately benefit educators by providing ways to harness the ANS and hopefully improve math readiness in young children.

Using reliability of change analysis to evaluate post-acute neuro-rehabilitation

BACKGROUND

It is important to evaluate change in order to re-assure commissioners, staff and patients of the effectiveness of interventions, but also in order to identify areas for improvement.

OBJECTIVE

To consider whether analysis of improvement at the level of the individual, taking into account measurement error, may offer a further valuable way to assess change and inform service development over considering change at the group level in a post-acute neuro-rehabilitation unit.

METHOD

Pre and post intervention Scores on the FIM+FAM Full Scale and Cognitive and Motor subscales were considered for eighteen patients aged between 35 and 81 with mixed diagnoses who attended a post-acute inpatient neuro-rehabilitation unit for treatment.

RESULTS

Statistically significant improvements were achieved on the FIM+FAM Full Scale and Cognitive and Motor subscales in a whole group analysis. Reliable change analyses for each patient within each subscale however identified only half of the sample achieved reliable improvement within the Motor domain and just one person within the Cognitive domain (5.6%).

CONCLUSIONS

Findings are consistent with the emphasis of the rehabilitation unit on physical/motor function, and unsurprising as many of those assessed had multiple sclerosis, an often deteriorative condition. Use of reliable change analysis allowed a more detailed understanding of intervention impact, potentially identifying what services reliably work for whom, thereby informing future planning.

A meta-analysis of math performance in Turner syndrome

AIM

Studies investigating the relationship between Turner syndrome and math learning disability have used a wide variation of tasks designed to test various aspects of mathematical competencies. Although these studies have revealed much about the math deficits common to Turner syndrome, their diversity makes comparisons between individual studies difficult. As a result, the consistency of outcomes among these diverse measures remains unknown. The overarching aim of this review is to provide a systematic meta-analysis of the differences in math and number performance between females with Turner syndrome and age-matched neurotypical peers.

METHOD

We provide a meta-analysis of behavioral performance in Turner syndrome relative to age-matched neurotypical populations on assessments of math and number aptitude. In total, 112 comparisons collected across 17 studies were included.

RESULTS

Although 54% of all statistical comparisons in our analyses failed to reject the null hypothesis, our results indicate that meaningful group differences exist on all comparisons except those that do not require explicit calculation.

INTERPRETATION

Taken together, these results help elucidate our current understanding of math and number weaknesses in Turner syndrome, while highlighting specific topics that require further investigation.

Enhancing Cognitive Abilities with Comprehensive Training: A Large, Online, Randomized, Active-Controlled Trial

Background

A variety of studies have demonstrated gains in cognitive ability following cognitive training interventions. However, other studies have not shown such gains, and questions remain regarding the efficacy of specific cognitive training interventions. Cognitive training research often involves programs made up of just one or a few exercises, targeting limited and specific cognitive endpoints. In addition, cognitive training studies typically involve small samples that may be insufficient for reliable measurement of change. Other studies have utilized training periods that were too short to generate reliable gains in cognitive performance.

Methods

The present study evaluated an online cognitive training program comprised of 49 exercises targeting a variety of cognitive capacities. The cognitive training program was compared to an active control condition in which participants completed crossword puzzles. All participants were recruited, trained, and tested online (N = 4,715 fully evaluable participants). Participants in both groups were instructed to complete one approximately 15-minute session at least 5 days per week for 10 weeks.

Results

Participants randomly assigned to the treatment group improved significantly more on the primary outcome measure, an aggregate measure of neuropsychological performance, than did the active control group (Cohen’s d effect size = 0.255; 95% confidence interval = [0.198, 0.312]). Treatment participants showed greater improvements than controls on speed of processing, short-term memory, working memory, problem solving, and fluid reasoning assessments. Participants in the treatment group also showed greater improvements on self-reported measures of cognitive functioning, particularly on those items related to concentration compared to the control group (Cohen’s d = 0.249; 95% confidence interval = [0.191, 0.306]).

Conclusion

Taken together, these results indicate that a varied training program composed of a number of tasks targeted to different cognitive functions can show transfer to a wide range of untrained measures of cognitive performance.

Trial Registration

ClinicalTrials.gov NCT-02367898

Computerized cognitive training interventions to improve neuropsychological outcomes: evidence and future directions

Age-related cognitive decline is common and may affect memory, orientation, attention, abstract thinking and perception, which may lead to substantial difficulties and disabilities in everyday life. Much evidence suggests that computerized cognitive training interventions may mitigate decline by improving neuropsychological outcomes in older adults, but there is clearly a need for large-scale, methodologically rigorous comparative effectiveness trials in the area. This article underscores that need and reviews eight trials that met a set of predetermined criteria before highlighting two novel and complementary analytic methods - big data analytics and network meta-analysis - that may be used to facilitate decisions regarding which cognitive training programs should serve as candidate interventions for large comparative effectiveness trials.

Aberrant parietal cortex developmental trajectories in girls with Turner syndrome and related visual-spatial cognitive development: a preliminary study

Turner syndrome (TS) arises from partial or complete absence of the X-chromosome in females. Girls with TS show deficits in visual-spatial skills as well as reduced brain volume and surface area in the parietal cortex which supports these cognitive functions. Thus, measuring the developmental trajectory of the parietal cortex and the associated visual-spatial cognition in TS may provide novel insights into critical brain-behavior associations. In this longitudinal study, we acquired structural MRI data and assessed visual-spatial skills in 16 (age: 8.23 ± 2.5) girls with TS and 13 age-matched controls over two time-points. Gray and white matter volume, surface area and cortical thickness were calculated from surfaced based segmentation of bilateral parietal cortices, and the NEPSY Arrows subtest was used to assess visual-spatial ability. Volumetric and cognitive scalars were modeled to obtain estimates of age-related change. The results show aberrant growth of white matter volume (P = 0.011, corrected) and surface area (P = 0.036, corrected) of the left superior parietal regions during childhood in girls with TS. Other parietal sub-regions were significantly smaller in girls with TS at both time-points but did not show different growth trajectories relative to controls. Furthermore, we found that visual-spatial skills showed a widening deficit for girls with TS relative to controls (P = 0.003). Young girls with TS demonstrate an aberrant trajectory of parietal cortical and cognitive development during childhood. Elucidating aberrant neurodevelopmental trajectories in this population is critical for determining specific stages of brain maturation that are particularly dependent on TS-related genetic and hormonal factors.

Intra-individual variability in women with breast cancer

Studies assessing cognitive functioning in women treated for breast cancer have used primarily standardized neuropsychological tests and examined accuracy and/or reaction time as outcome measures: they have been inconsistent in identifying the cognitive domains affected and the severity of deficits. In other contexts of neural development and disorders, measures of Intra-individual variability (IIV) have proven useful in identifying subtleties in performance deficits that are not captured by measures of central tendency. This article presents proof of concept that assessing IIV may also increase understanding of the cognitive effects of cancer treatment. We analyzed mean accuracy and reaction time, as well as IIV from 65 women with breast cancer and 28 age and education matched controls who performed the Conner's Continuous Performance Test, a "Go-NoGo" task. Although there were no significant differences between groups using measures of central tendency, there was a group × inter-stimulus interval (ISI) interaction for IIV Dispersion (p < .001). Patient Dispersion was more variable at shorter ISI than controls and less variable at long ISI, suggesting greater sensitivity to presentation speed. Interpretation of IIV differences requires further investigation. Our results suggest that future studies would benefit from designs that allow analysis of IIV measures in studies assessing cognition in cancer survivors.

Math practice and its influence on math skills and executive functions in adolescents with mild to borderline intellectual disability

Adolescents with mild to borderline intellectual disability (MBID) often complete schooling without mastering basic math skills, even though basic math is essential for math-related challenges in everyday life. Limited attention to cognitive skills and low executive functioning (EF) may cause this delay. We aimed to improve math skills in an MBID-sample using computerized math training. Also, it was investigated whether EF and math performance were related and whether computerized math training had beneficial effects on EF. The sample consisted of a total of 58 adolescents (12-15 years) from special education. Participants were randomly assigned to either the experimental group or a treatment as usual (TAU) group. In the experimental condition, participants received 5 weeks of training. Math performance and EF were assessed before and after the training period. Math performance improved equally in both groups. However, frequently practicing participants improved more than participants in the control group. Visuo-spatial memory skills were positively related to addition and subtraction skills. Transfer effects from math training to EF were absent. It is concluded that math skills may increase if a reasonable effort in practicing math skills is made. The relation between visuo-spatial memory skills provides opportunities for improving math performance.

Update on Turner and Noonan syndromes

Turner syndrome (TS) and Noonan syndrome (NS) have short stature as a constant feature; however, both conditions can present clinicians with a challenging array of genetic, cardiovascular, developmental, and psychosocial issues. In recent years, important advances have been achieved in each of these areas. This article reviews these two syndromes and provides updates on recent developments in diagnostic evaluation, growth and development, psychological issues, and treatment options for patients with TS and NS.

Turner syndrome: advances in understanding altered cognition, brain structure and function

PURPOSE OF REVIEW

Turner syndrome, which results from the complete or partial loss of a sex chromosome, is associated with a particular pattern of cognitive impairments and strengths and an increased risk for specific neurodevelopmental disorders. This review highlights recent progress in understanding brain structure and function in Turner syndrome and identifies several critical research needs.

RECENT FINDINGS

Recent work on social cognition in Turner syndrome has identified a range of difficulties despite a maintained social appetite, a disconnect which could result in distress for affected individuals. Progress has been made in identifying foundational deficits in attention and executive function that could explain visual-spatial and arithmetical impairments. Neuroimaging studies have advanced our understanding of brain development and function through the application of cutting edge analysis techniques. Haploinsufficiency of genes, failure to express parentally imprinted genes, uncovering of X chromosome mutations, and gonadal steroid deficiency may all contribute to altered brain development, but additional work is required to link specific mechanisms to specific phenotypes. Also needed are studies of interventions to assist individuals with Turner syndrome in visual-spatial, mathematical, and social skills.

SUMMARY

Ultimately a better understanding of brain structure and function in Turner syndrome will generate new therapeutic approaches for this population.

Cognition and behavior in Turner syndrome: a brief review

There is increasing evidence that Turner syndrome is associated with a distinct pattern of cognitive and neurophysiological characteristics. Typically this has been characterized by relative strengths in verbal skills, contrasting with relative weaknesses in arithmetic, visuospatial and executive function domains. Potential differences in social cognitive processing have also been identified. More recently, applications of neuroimaging techniques have further elucidated underlying differences in brain structure, function and connectivity in individuals with Turner syndrome. Ongoing research in this area is focused on establishing a unified mechanistic model incorporating genetic influences from the X chromosome, sex hormone contributions, neuroanatomical variation and differences in cognitive processes. This review broadly covers current understanding of how X-monosomy impacts neurocognitive phenotype both from the perspective of cognitive-behavioral and neuroimaging studies. Furthermore, relevant clinical aspects of identifying potential learning difficulties and providing anticipatory guidance for affected individuals with TS, are briefly discussed.