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Quarterly Journal of Experimental... Jan 2022People are willing to spend time and money to receive information and content they are curious about, such as answers to trivia questions, suggesting they find...
People are willing to spend time and money to receive information and content they are curious about, such as answers to trivia questions, suggesting they find information rewarding. In neurotypical adults, states of high curiosity satisfaction are also known to enhance the learning and memory of information encountered in that state. Here, we investigated whether the relationship between curiosity, satisfaction, and learning was altered in a group with specific learning difficulty (dyslexia). Using a willingness-to-wait paradigm, we observed that adults with and without dyslexia are willing to spend time waiting for verbal and visual information. This indicates that the same "wanting" mechanisms are seen in individuals with dyslexia for information. We then examined whether information that was desirable was also associated with enhanced memory. Our findings indicate that information does function like a reward, with the gap between expected and received information driving memory. However, this memory effect was attenuated in individuals with dyslexia. These findings point to the need to understand how reward drives learning and why this relationship might differ in dyslexia.
Topics: Adult; Dyslexia; Exploratory Behavior; Humans; Learning; Reward
PubMed: 34293988
DOI: 10.1177/17470218211037474 -
Industrial Psychiatry Journal Nov 2023With a global dyslexia prevalence of at least 10%, significant numbers of students with dyslexia go undiagnosed and their symptoms unaddressed, but with timely...
BACKGROUND
With a global dyslexia prevalence of at least 10%, significant numbers of students with dyslexia go undiagnosed and their symptoms unaddressed, but with timely intervention, 90% of dyslexic children can be educated in regular inclusive classrooms.
AIM
This study aimed to estimate the prevalence of dyslexia among primary schoolchildren in government and private schools.
MATERIAL AND METHODS
A cross-sectional study on 128 primary schoolchildren attending selected government and private schools in Western Maharashtra was conducted and evaluated using the Search tool, which is a standardized study tool for screening dyslexia. Microsoft Excel and MedCalc version 3.1 were used for data entry and analysis. The prevalence of dyslexia was estimated, and differences between groups were evaluated using appropriate tests.
RESULTS
Of the total sample size of 128 children, findings showed 10.9% of students as dyslexic, 9.3% as vulnerable, and the remaining 79.8% as non-dyslexic. Of 14 dyslexic children, 10 were found to be from government schools and the remaining four were from private schools.
CONCLUSION
The high prevalence of dyslexia even in a small study sample size is a matter of concern and emphasizes the need for extensive research and initiatives, including awareness campaigns among teachers, parents, and school authorities, and the importance of detection of undiagnosed dyslexic children as early as possible and providing them with appropriate interventions.
PubMed: 38370946
DOI: 10.4103/ipj.ipj_196_23 -
Vision Research Feb 2021Previous studies showed that the lateral masking of a fast-moving low spatial frequency (SF) target was strong when exerted by static flankers of lower or equal to the...
Previous studies showed that the lateral masking of a fast-moving low spatial frequency (SF) target was strong when exerted by static flankers of lower or equal to the target SF and absent when flankers' SF was higher than the target's one. These masking and unmasking effects have been interpreted as due to Magnocellular-Magnocellular (M-M) inhibition and Parvocellular-on-Magnocellular (P-M) disinhibitory coactivation, respectively. Based on the hypothesis that the balance between the two systems is perturbed in Developmental Dyslexia (DD), we asked whether dyslexic children (DDs) behaved differently than Typically Developing children (TDs) in conditions of lateral masking. DDs and TDs performed a motion discrimination task, of a .5c/deg Gabor target moving at 16 deg/sec, either isolated or flanked by static Gabors with a SF of .125, .5 or 2 c/deg (Experiment 1). As a control, they also performed a contrast detection task of a static target, either isolated or flanked (Experiment 2). DDs did not perform any different from TDs with either a static target or an isolated moving target of low spatial frequency, thus suggesting efficient feedforward Magnocellular (M) and Parvocellular (P) processing. Also, DDs showed similar contrast thresholds to TDs in the M-M inhibition condition. Conversely, DDs did not recover from lateral masking in the M-P coactivation condition. In addition, their performance in this condition negatively correlated with non-words accuracy, supporting the suggestion that an inefficient Magno-Parvo coactivation may possibly be associated to both higher visual suppression and reduced perceptual stability during reading.
Topics: Child; Dyslexia; Humans; Reading; Visual Pathways
PubMed: 33310233
DOI: 10.1016/j.visres.2020.10.008 -
Neuroscience and Biobehavioral Reviews Jan 2022Behavioral research supports the efficacy of intervention for reading disability, but the brain mechanisms underlying improvement in reading are not well understood.... (Meta-Analysis)
Meta-Analysis Review
Behavioral research supports the efficacy of intervention for reading disability, but the brain mechanisms underlying improvement in reading are not well understood. Here, we review 39 neuroimaging studies of reading intervention to characterize links between reading improvement and changes in the brain. We report evidence of changes in activation, connectivity, and structure within the reading network, and right hemisphere, frontal and sub-cortical regions. Our meta-analysis of changes in brain activation from pre- to post- reading intervention in eight studies did not yield any significant effects. Methodological heterogeneity among studies may contribute to the lack of significant meta-analytic findings. Based on our qualitative synthesis, we propose that brain changes in response to intervention should be considered in terms of interactions among distributed cognitive, linguistic and sensory systems, rather than via a "normalized" vs. "compensatory" dichotomy. Further empirical research is needed to identify effects of moderating factors such as features of intervention programs, neuroimaging tasks, and individual differences among participants.
Topics: Brain; Brain Mapping; Dyslexia; Humans; Magnetic Resonance Imaging; Neuronal Plasticity
PubMed: 34856223
DOI: 10.1016/j.neubiorev.2021.11.011 -
Frontiers in Human Neuroscience 2020Evolution fuels interindividual variability in neuroplasticity, reflected in brain anatomy and functional connectivity of the expanding neocortical regions subserving... (Review)
Review
Evolution fuels interindividual variability in neuroplasticity, reflected in brain anatomy and functional connectivity of the expanding neocortical regions subserving reading ability. Such variability is orchestrated by an evolutionarily conserved, competitive balance between epigenetic, stress-induced, and cognitive-growth gene expression programs. An evolutionary developmental model of dyslexia, suggests that prenatal and childhood subclinical stress becomes a risk factor for dyslexia when physiological adaptations to stress promoting adaptive fitness, may attenuate neuroplasticity in the brain regions recruited for reading. Stress has the potential to blunt the cognitive-growth functions of the predominantly right hemisphere Ventral and Dorsal attention networks, which are primed with high entropic levels of synaptic plasticity, and are critical for acquiring beginning reading skills. The attentional networks, in collaboration with the stress-responsive Default Mode network, modulate the entrainment and processing of the low frequency auditory oscillations (1-8 Hz) and visuospatial orienting linked etiologically to dyslexia. Thus, dyslexia may result from positive, but costly adaptations to stress system dysregulation: protective measures that reset the stress/growth balance of processing to favor the Default Mode network, compromising development of the attentional networks. Such a normal-variability conceptualization of dyslexia is at odds with the frequent assumption that dyslexia results from a neurological abnormality. To put the normal-variability model in the broader perspective of the state of the field, a traditional evolutionary account of dyslexia is presented to stimulate discussion of the scientific merits of the two approaches.
PubMed: 33551772
DOI: 10.3389/fnhum.2020.575546 -
Journal of Neurodevelopmental Disorders Aug 2023Developmental dyslexia (DD) and attention deficit/hyperactivity disorder (ADHD) are highly comorbid neurodevelopmental disorders. Individuals with DD or ADHD have both...
BACKGROUND
Developmental dyslexia (DD) and attention deficit/hyperactivity disorder (ADHD) are highly comorbid neurodevelopmental disorders. Individuals with DD or ADHD have both been shown to have deficits in white matter tracts associated with reading and attentional control networks. However, white matter diffusivity in individuals comorbid with both DD and ADHD (DD + ADHD) has not been specifically explored.
METHODS
Participants were 3 and 4 graders (age range = 7 to 11 years; SD = 0.69) from three diagnostic groups ((DD (n = 40), DD + ADHD (n = 22), and typical developing (TD) (n = 20)). Behavioral measures of reading and attention alongside measures of white matter diffusivity were collected for all participants.
RESULTS
DD + ADHD and TD groups differed in mean fractional anisotropy (FA) for the left and right Superior Longitudinal Fasciculus (SLF)-Parietal Terminations and SLF-Temporal Terminations. Mean FA for the DD group across these SLF tracts fell between the lower DD + ADHD and higher TD averages. No differences in mean diffusivity nor significant brain-behavior relations were found.
CONCLUSIONS
Findings suggest that WM diffusivity in the SLF increases along a continuum across DD + ADHD, DD, and TD.
Topics: White Matter; Dyslexia; Attention Deficit Disorder with Hyperactivity; Analysis of Variance; Attention; Humans; Child; Reading; Executive Function
PubMed: 37550628
DOI: 10.1186/s11689-023-09495-9 -
BioMed Research International 2021We enrolled pediatric subjects with developmental dyslexia and, as a control group, healthy age- and sex-matched subjects without developmental dyslexia. Thyroid... (Clinical Trial)
Clinical Trial
METHODS
We enrolled pediatric subjects with developmental dyslexia and, as a control group, healthy age- and sex-matched subjects without developmental dyslexia. Thyroid function was evaluated in subjects with developmental dyslexia measuring serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). Thyroid autoimmunity was evaluated in all subjects measuring antithyroid peroxidase (TPO-Ab) and antithyroglobulin (TG-Ab) antibodies. In subjects with developmental dyslexia, thyroid ultrasonography (US) was also performed.
RESULTS
We enrolled 51 subjects with developmental dyslexia (M : F = 39 : 12, mean age 12.4 ± 9 years) and 34 controls (M : F = 24 : 10, mean age 10.8 ± 4 years). TPO-Ab positivity was significantly higher in subjects with developmental dyslexia compared to controls (60.8% vs. 2.9%, < 0.001), while no significant difference was found in TG-Ab positivity (16% vs. 5.8%). Thyroid US performed in 49 subjects with developmental dyslexia revealed a thyroiditis pattern in 60%.
CONCLUSIONS
We found an extremely high prevalence of thyroid autoimmunity in children with developmental dyslexia. Further studies are needed to confirm our observations, but our findings may change the approach to this disorder and eventually lead to a systematic determination of thyroid autoimmunity in children with developmental dyslexia.
Topics: Adolescent; Adult; Autoantibodies; Child; Dyslexia; Female; Humans; Male; Prevalence; Thyroid Function Tests; Thyroid Hormones; Thyroiditis, Autoimmune
PubMed: 33628813
DOI: 10.1155/2021/7656843 -
Neuropsychologia Jun 2022Extensive studies have reported significant activation of the cerebellum in reading and reading-related tasks. However, it has remained unclear how the cerebellum... (Review)
Review
Extensive studies have reported significant activation of the cerebellum in reading and reading-related tasks. However, it has remained unclear how the cerebellum contributes to reading and how reading-related regions in the cerebrum are related to those in the cerebellum. In this review, by summarizing previous literature, we observe that multiple cerebellar areas are engaged in reading and vary in their contributions to reading. Moreover, the cerebellar reading-related areas are selectively connected with the cerebral areas with the same functional specificity. Abnormalities in the cerebro-cerebellar connection are also associated with reading impairments. We thus propose the cerebro-cerebellar mapping hypothesis, which suggests that the cerebellum might have another reading-related network rather than serving as a neural hub. This network maps to and collaborates with its functionally corresponding network in the cerebrum. This framework heightens the importance of the cerebellum to reading and provides new insights into the relationship between the cerebellum, cerebrum, and reading development.
Topics: Brain Mapping; Cerebellum; Dyslexia; Humans; Magnetic Resonance Imaging; Reading
PubMed: 35378104
DOI: 10.1016/j.neuropsychologia.2022.108231 -
Journal of Cognition 2023What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of...
What are the causes of dyslexia? Decades of research reflect a determined search for a single cause where a common assumption is that dyslexia is a consequence of problems with converting phonological information into lexical codes. But reading is a highly complex activity requiring many well-functioning mechanisms, and several different visual problems have been documented in dyslexic readers. We critically review evidence from various sources for the role of visual factors in dyslexia, from magnocellular dysfunction through accounts based on abnormal eye movements and attentional processing, to recent proposals that problems with high-level vision contribute to dyslexia. We believe that the role of visual problems in dyslexia has been underestimated in the literature, to the detriment of the understanding and treatment of the disorder. We propose that rather than focusing on a single core cause, the role of visual factors in dyslexia fits well with risk and resilience models that assume that several variables interact throughout prenatal and postnatal development to either promote or hinder efficient reading.
PubMed: 37397349
DOI: 10.5334/joc.287 -
Brain Sciences Jan 2022Developmental dyslexia is a complex reading disorder involving genetic and environmental factors. After more than a century of research, its etiology remains debated.... (Review)
Review
Developmental dyslexia is a complex reading disorder involving genetic and environmental factors. After more than a century of research, its etiology remains debated. Two hypotheses are often put forward by scholars to account for the causes of dyslexia. The most common one, the linguistic hypothesis, postulates that dyslexia is due to poor phonological awareness. The alternative hypothesis considers that dyslexia is caused by visual-attentional deficits and abnormal eye movement patterns. This article reviews a series of selected event-related brain potential (ERP) and eye movement studies on the reading ability of dyslexic individuals to provide an informed state of knowledge on the etiology of dyslexia. Our purpose is to show that the two abovementioned hypotheses are not necessarily mutually exclusive, and that dyslexia should rather be considered as a multifactorial deficit.
PubMed: 35053816
DOI: 10.3390/brainsci12010073