Visuospatial deficits of dyslexic children

Developmental Dyslexia: Disorder or Specialization in Exploration?

We raise the new possibility that people diagnosed with developmental dyslexia (DD) are specialized in explorative cognitive search, and rather than having a neurocognitive disorder, play an essential role in human adaptation. Most DD research has studied educational difficulties, with theories framing differences in neurocognitive processes as deficits. However, people with DD are also often proposed to have certain strengths - particularly in realms like discovery, invention, and creativity - that deficit-centered theories cannot explain. We investigate whether these strengths reflect an underlying explorative specialization. We re-examine experimental studies in psychology and neuroscience using the framework of cognitive search, whereby many psychological processes involve a trade-off between exploration and exploitation. We report evidence of an explorative bias in DD-associated cognitive strategies. High DD prevalence and an attendant explorative bias across multiple areas of cognition suggest the existence of explorative specialization. An evolutionary perspective explains the combination of findings and challenges the view that individuals with DD have a disorder. In cooperating groups, individual specialization is favored when features that confer fitness benefits are functionally incompatible. Evidence for search specialization suggests that, as with some other social organisms, humans mediate the exploration-exploitation trade-off by specializing in complementary strategies. The existence of a system of collective cognitive search that emerges through collaboration would help to explain our species' exceptional adaptiveness. It also aligns with evidence for substantial variability during our evolutionary history and the notion that humans are adapted not to a particular habitat but to variability itself. Specialization creates interdependence and necessitates balancing complementary strategies. Reframing DD therefore underscores the urgency of changing certain cultural practices to ensure we do not inhibit adaptation. Key improvements would remove cultural barriers to exploration and nurture explorative learning in education, academia, and the workplace, as well as emphasize collaboration over competition. Specialization in complementary search abilities represents a meta-adaptation; through collaboration, this likely enables human groups (as a species and as cultural systems) to successfully adapt. Cultural change to support this system of collaborative search may therefore be essential in confronting the challenges humanity now faces.

Specific Learning Disorder in Children and Adolescents, a Scoping Review on Motor Impairments and Their Potential Impacts

Mastering motor skills is important for children to achieve functional mobility and participate in daily activities. Some studies have identified that students with specific learning disorders (SLD) could have impaired motor skills; however, this postulate and the potential impacts remain unclear. The purpose of the scoping review was to evaluate if SLD children have motor impairments and examine the possible factors that could interfere with this assumption. The sub-objective was to investigate the state of knowledge on the lifestyle behavior and physical fitness of participants with SLD and to discuss possible links with their motor skills. Our scoping review included preregistration numbers and the redaction conformed with the PRISMA guidelines. A total of 34 studies published between 1990 and 2022 were identified. The results of our scoping review reflected that students with SLD have poorer motor skills than their peers. These motor impairments are exacerbated by the complexity of the motor activities and the presence of comorbidities. These results support our sub-objective and highlight the link between motor impairments and the sedentary lifestyle behavior of SLDs. This could lead to deteriorating health and motor skills due to a lack of motor experience, meaning that this is not necessarily a comorbidity. This evidence emphasizes the importance of systematic clinical motor assessments and physical activity adaptations.

The cognitive basis of dyslexia in school-aged children: A multiple case study in a transparent orthography

This study focuses on the role of numerous cognitive skills such as phonological awareness (PA), rapid automatized naming (RAN), visual and selective attention, auditory skills, and implicit learning in developmental dyslexia. We examined the (co)existence of cognitive deficits in dyslexia and assessed cognitive skills’ predictive value for reading. First, we compared school‐aged children with severe reading impairment (n = 51) to typical readers (n = 71) to explore the individual patterns of deficits in dyslexia. Children with dyslexia, as a group, presented low PA and RAN scores, as well as limited implicit learning skills. However, we found no differences in the other domains. We found a phonological deficit in 51% and a RAN deficit in 26% of children with dyslexia. These deficits coexisted in 14% of the children. Deficits in other cognitive domains were uncommon and most often coexisted with phonological or RAN deficits. Despite having a severe reading impairment, 26% of children with dyslexia did not present any of the tested deficits. Second, in a group of children presenting a wide range of reading abilities (N = 211), we analysed the relationship between cognitive skills and reading level. PA and RAN were independently related to reading abilities. Other skills did not explain any additional variance. The impact of PA and RAN on reading skills differed. While RAN was a consistent predictor of reading, PA predicted reading abilities particularly well in average and good readers with a smaller impact in poorer readers.

A systematic review and meta-analysis of the accuracy of the clock drawing test (CDT) in the identification of delirium in older hospitalised patients

Objective: Delirium is a common neurocognitive syndrome among hospitalised older adults. The clock drawing test (CDT) is a relatively simple bedside test of cognitive function. This systematic review and meta-analysis examine the accuracy of the CDT in identifying delirium in hospitalised older adults.Methods: PRISMA guidelines were used to report the identified studies. Pubmed, SCOPUS, and Ovid and EBSCO platforms (including MEDLINE ®, PsycINFO, PsycEXTRA, EMCARE, CINAHL and EMBASE databases) were searched. Studies were assessed for methodological quality using the Downs and Black Tool. Data were extracted regarding the number of delirious/not delirious, number with normal and abnormal CDT, age, and MMSE scores, and information regarding CDT scoring, criteria for diagnosis of delirium and setting of the study. Analysis was carried out with the "Mada" and "Metatron" packages of R software.Results: Fifteen studies were examined. The number of participants was 2199, of whom 597 (27.15%) were diagnosed with delirium. The overall sensitivity of CDT in the absence of any formal cognitive test was 0.76 (0.58-0.87) with specificity of 0.70 (0.51-0.83). When the MMSE was taken into account, the specificity and sensitivity reduced to 0.51. Diagnostic criteria for delirium, scoring method of CDT, age of participants and setting significantly (p < 0.05) affect the sensitivity and specificity of the CDT.Conclusion: Although, the CDT is generally considered to be a simple and easy to administer screening tool for cognitive impairment in older hospitalised adults, when a more formal cognitive test is used its sensitivity and specificity to detect delirium is low.

Pre-schoolers' visual perception and attention networks influencing naming speed: An individual difference perspective

Naming speed is considered to be one of the essential components used to predict reading capacity in school. The current study examined how visual perception and attention networks influence naming speed, and analyzed the relationship between visual perception and attention networks. The total number of participants was 163 Thai preschool children between the ages of five and seven years selected through multistage random sampling. Visual perception, attention networks, and naming speed were assessed using the Developmental Test of Visual Perception 3 (DTVP-3), Attention Network Task (ANT), and Rapid Automatized Naming (RAN), respectively. Structural equation modeling was used to test naming speed hypotheses. The hypothesis of a causal model was supported by the evidence generated by this study. A direct positive association between both visual perception and attention networks to naming speed was observed. Compared with attention networks, visual perception had a higher significant effect on naming speed performance. Consequently, children who have higher visual perception are more likely to demonstrate a better naming speed performance. These results indicate that visual perception is strongly urged to naming speed, as doing so can help predict children's reading readiness before they start learning to read.

Correspondence and cluster analysis of free-drawn clocks in a group of children and adolescents with neurological and psychiatric diseases

The present work addresses the identification and qualitative assessment of errors that appear in a free-drawn clock-drawing test representing the time 8:20 in a sample of 455 children and adolescents with neurological diseases and their controls. The authors sought to verify whether the occurrence of particular errors in the clock drawings significantly differentiates the clinical groups. For statistical evaluation of the results, we applied correspondence analysis and cluster analysis. The results of the study showed that three types of errors played an important role in the differentiation of the groups: spatial neglect, mirror reflection, and phonological depletion.

The utility of the clock drawing test in detection of delirium in elderly hospitalised patients

OBJECTIVES

Delirium is common neuropsychiatric condition among elderly inpatients. The clock drawing test (CDT) has been used widely as bedside screening tool in assessing cognitive impairment in elderly people. Previous studies which evaluate its usefulness in delirium reported conflicting results. The objective of this study was to evaluate the utility of CDT to detect delirium in elderly medical patients.

METHOD

Prospective, observational, longitudinal study. All acute medical admissions 70 years of age and above were approached within 72 hours of admission for recruitment. Patients eligible for inclusion were assessed four times, twice weekly during admission. Assessment included Confusion Assessment Method (CAM), Delirium Rating Scale (DRS-98R), Montreal Cognitive Assessment (MoCA), Acute Physiology and Chronic Health Evaluation II (APACHE) II, and CDT. Data was analysed using a linear mixed effect model.

RESULTS

Three hundred and twenty-three assessments with the CDT were performed on 200 subjects (50% male, mean age 81.13; standard deviation: 6.45). The overall rate of delirium (CAM+) during hospitalisation was 23%. There was a significant negative correlation between the CDT and DRS-R98 scores (Pearson correlation r = -0.618, p < 0.001), CDT and CAM (Spearman's rho = -0.402, p < 0.001) and CDT and total MoCA score (Pearson's r = 0.767, p < 0.001). However, when the data were analysed longitudinally controlling for all the factors, we found that cognitive function and age were significant factors associated with CDT scores (p < .0001): neither the presence nor the severity of delirium had an additional significant effect on the CDT.

CONCLUSION

CDT score reflects cognitive impairment, independently of the presence or severity of delirium. The CDT is not a suitable test for delirium in hospitalised elderly patients.

Anxiety and Depression in Children With Nonverbal Learning Disabilities, Reading Disabilities, or Typical Development

The main goal of the present study was to shed further light on the psychological characteristics of children with different learning disability profiles aged between 8 and 11 years, attending from third to sixth grade. Specifically, children with nonverbal learning disabilities (NLD), reading disabilities (RD), or a typical development (TD) were tested. In all, 15 children with NLD, 15 with RD, and 15 with TD were administered self-report questionnaires to assess different types of anxiety and depression symptoms. Both NLD and RD children reported experiencing more generalized and social anxiety than TD, the NLD children reported more severe anxiety about school and separation than TD, and the children with RD had worse depressive symptoms than those with NLD or TD.

Attention dysfunction subtypes of developmental dyslexia

Background

Previous studies indicate that many different aspects of attention are impaired in children diagnosed with developmental dyslexia (DD). The objective of the present study was to identify cognitive profiles of DD on the basis of attentional test performance.

Material/Methods

78 children with DD (30 girls, 48 boys, mean age of 12 years ±8 months) and 32 age- and sex-matched non-dyslexic children (14 girls, 18 boys) were examined using a battery of standardized tests of reading, phonological and attentional processes (alertness, covert shift of attention, divided attention, inhibition, flexibility, vigilance, and visual search). Cluster analysis was used to identify subtypes of DD.

Results

Dyslexic children showed deficits in alertness, covert shift of attention, divided attention, flexibility, and visual search. Three different subtypes of DD were identified, each characterized by poorer performance on the reading, phonological awareness, and visual search tasks. Additionally, children in cluster no. 1 displayed deficits in flexibility and divided attention. In contrast to non-dyslexic children, cluster no. 2 performed poorer in tasks involving alertness, covert shift of attention, divided attention, and vigilance. Cluster no. 3 showed impaired covert shift of attention.

Conclusions

These results indicate different patterns of attentional impairments in dyslexic children. Remediation programs should address the individual child’s deficit profile.

Altered neuronal response during rapid auditory processing and its relation to phonological processing in prereading children at familial risk for dyslexia

Developmental dyslexia (DD) is a learning disability affecting 5-17% of children. Although researchers agree that DD is characterized by deficient phonological processing (PP), its cause is debated. It has been suggested that altered rapid auditory processing (RAP) may lead to deficient PP in DD and studies have shown deficient RAP in individuals with DD. Functional neuroimaging (fMRI) studies have implicated hypoactivations in left prefrontal brain regions during RAP in individuals with DD. When and how these neuronal alterations evolve remains unknown. In this article, we investigate functional networks during RAP in 28 children with (n = 14) and without (n = 14) a familial risk for DD before reading onset (mean: 5.6 years). Results reveal functional alterations in left-hemispheric prefrontal regions during RAP in prereading children at risk for DD, similar to findings in individuals with DD. Furthermore, activation during RAP in left prefrontal regions positively correlates with prereading measures of PP and with neuronal activation during PP in posterior dorsal and ventral brain areas. Our results suggest that neuronal differences during RAP predate reading instruction and thus are not due to experience-dependent brain changes resulting from DD itself and that there is a functional relationship between neuronal networks for RAP and PP within the prereading brain.