Developmental Dyslexia: Disorder or Specialization in Exploration?

Unraveling the complex interplay between statistical learning and working memory in Chinese children with and without dyslexia across different ages

The relation between statistical learning and working memory in children with developmental dyslexia (DD) remains unclear. This study employed a distributional and a conditional statistical learning experiment and a working memory task to examine this relation in 651 Chinese 6- to 12-year-olds with and without DD (NDD = 199, 101 females; NwoDD = 452, 227 females; participated 2014-2019). Results showed working memory positively associated with recognizing high-predictable and familiar items in both groups, but negatively associated with recognizing unfamiliar items in the DD group only. These findings uncovered the complex interplay between statistical learning and working memory, demonstrating how different working memory abilities in children with and without DD relate to various statistical learning mechanisms at the item level.

A Life Outside

How do the morphologies of organisms affect their physical interactions with the environment and other organisms? My research in marine systems couples field studies of the physical habitats, life history strategies, and ecological interactions of organisms with laboratory analyses of their biomechanics. Here, I review how we pursued answers to three questions about marine organisms: (a) how benthic organisms withstand and utilize the water moving around them, (b) how the interaction between swimming and turbulent ambient water flow affects where small organisms go, and (c) how hairy appendages catch food and odors. I also discuss the importance of different types of mentors, the roadblocks for women in science when I started my career, the challenges and delights of interdisciplinary research, and my quest to understand how I see the world as a dyslexic.

Marginalising dyslexic researchers is bad for science

Communication in the sciences is often based on text, which places researchers with dyslexia at a disadvantage. However, this means that science is missing out on the original insights and specific strengths in exploration that dyslexic researchers bring to their disciplines. Here we discuss how the scientific community can address the challenges that dyslexic researchers face, and how science stands to benefit as a result. We discuss this in the context of a new theoretical framework proposing the existence of complementary learning strategies that could play a key role in scientific progress, particularly with regard to accelerating innovation.

The effect of specific learning difficulties on general practice written and clinical assessments

BACKGROUND

Substantial numbers of medical students and doctors have specific learning difficulties (SpLDs) and failure to accommodate their needs can disadvantage them academically. Evidence about how SpLDs affect performance during postgraduate general practice (GP) specialty training across the different licencing assessments is lacking. We aimed to investigate the performance of doctors with SpLDs across the range of licencing assessments.

METHODS

We adopted the social model of disability as a conceptual framework arguing that problems of disability are societal and that barriers that restrict life choices for people with disabilities need to be addressed. We used a longitudinal design linking Multi-Specialty Assessment (MSRA) records from 2016 and 2017 with their Applied Knowledge Test (AKT), Clinical Skills Assessment (CSA), Recorded Consultation Assessment (RCA) and Workplace Based Assessment (WPBA) outcomes up to 2021. Multivariable logistic regression models accounting for prior attainment and demographics were used to determine the SpLD doctors' likelihood of passing licencing assessments.

RESULTS

The sample included 2070 doctors, with 214 (10.34%) declaring a SpLD. Candidates declaring a SpLD were significantly less likely to pass the CSA (OR 0.43, 95% CI 0.26, 0.71, p = 0.001) but not the AKT (OR 0.96, 95% CI 0.44, 2.09, p = 0.913) or RCA (OR 0.81, 95% CI 0.35, 1.85, p = 0.615). Importantly, they were significantly more likely to have difficulties with WPBA (OR 0.28, 95% CI 0.20, 0.40, p < 0.001). When looking at licencing tests subdomains, doctors with SpLD performed significantly less well on the CSA Interpersonal Skills (B = -0.70, 95% CI -1.2, -0.19, p = 0.007) and the RCA Clinical Management Skills (B = -1.68, 95% CI -3.24, -0.13, p = 0.034).

CONCLUSIONS

Candidates with SpLDs encounter difficulties in multiple domains of the licencing tests and during their training. More adjustments tailored to their needs should be put in place for the applied clinical skills tests and during their training.

Distinct reinforcement learning profiles distinguish between language and attentional neurodevelopmental disorders

BACKGROUND

Theoretical models posit abnormalities in cortico-striatal pathways in two of the most common neurodevelopmental disorders (Developmental dyslexia, DD, and Attention deficit hyperactive disorder, ADHD), but it is still unclear what distinct cortico-striatal dysfunction might distinguish language disorders from others that exhibit very different symptomatology. Although impairments in tasks that depend on the cortico-striatal network, including reinforcement learning (RL), have been implicated in both disorders, there has been little attempt to dissociate between different types of RL or to compare learning processes in these two types of disorders. The present study builds upon prior research indicating the existence of two learning manifestations of RL and evaluates whether these processes can be differentiated in language and attention deficit disorders. We used a two-step RL task shown to dissociate model-based from model-free learning in human learners.

RESULTS

Our results show that, relative to neurotypicals, DD individuals showed an impairment in model-free but not in model-based learning, whereas in ADHD the ability to use both model-free and model-based learning strategies was significantly compromised.

CONCLUSIONS

Thus, learning impairments in DD may be linked to a selective deficit in the ability to form action-outcome associations based on previous history, whereas in ADHD some learning deficits may be related to an incapacity to pursue rewards based on the tasks' structure. Our results indicate how different patterns of learning deficits may underlie different disorders, and how computation-minded experimental approaches can differentiate between them.

Microbiome–Gut Dissociation in the Neonate: Autism-Related Developmental Brain Disease and the Origin of the Placebo Effect

While the importance of the intestinal microbiome has been realised for a number of years, the significance of the phrase microbiota–gut–brain axis is only just beginning to be fully appreciated. Our recent work has focused on the microbiome as if it were a single entity, modifying the expression of the genetic inheritance of the individual by the generation of interkingdom signalling molecules, semiochemicals, such as dopamine. In our view, the purpose of the microbiome is to convey information about the microbial environment of the mother so as to calibrate the immune system of the new-born, giving it the ability to distinguish harmful pathogens from the harmless antigens of pollen, for example, or to help distinguish self from non-self. In turn, this requires the partition of nutrition between the adult and its microbiome to ensure that both entities remain viable until the process of reproduction. Accordingly, the failure of a degraded microbiome to interact with the developing gut of the neonate leads to failure of this partition in the adult: to low faecal energy excretion, excessive fat storage, and concomitant problems with the immune system. Similarly, a weakened gut–brain axis distorts interoceptive input to the brain, increasing the risk of psychiatric diseases such as autism. These effects account for David Barker’s 1990 suggestion of “the fetal and infant origins of adult disease”, including schizophrenia, and David Strachan’s 1989 observation of childhood immune system diseases, such as hay fever and asthma. The industrialisation of modern life is increasing the intensity and scale of these physical and psychiatric diseases and it seems likely that subclinical heavy metal poisoning of the microbiome contributes to these problems. Finally, the recent observation of Harald Brüssow, that reported intestinal bacterial composition does not adequately reflect the patterns of disease, would be accounted for if microbial eukaryotes were the key determinant of microbiome effectiveness. In this view, the relative success of “probiotic” bacteria is due to their temporary immune system activation of the gut–brain axis, in turn suggesting a potential mechanism for the placebo effect.

Creativity, Eye-Movement Abnormalities, and Aesthetic Appreciation of Magritte’s Paintings

Dyslexic children have been shown to be more creative than their non-dyslexic counterparts. They have also been shown to have an abnormal oculomotor profile while viewing targets in free space, making vergence or saccadic eye movements while reading or when viewing Op art. They show a slower deceleration of their eye movements and a difficulty in coordinating their two eyes to obtain single fused vision in depth. Interestingly, their abnormal oculo-motor profile is exacerbated while reading more difficult texts. Given these differences, we postulate that dyslexics’ increased creativity may be related to their different eye movement control affecting how they perceive the world. Therefore, we decided to measure adolescent dyslexics’ creativity, oculomotor profile, and subjective responses while they viewed three paintings by Magritte. These were chosen to stimulate the perception of hidden conceptual spaces or stimulate conflict between the perception of the figural and textural content. For the first time to our knowledge, dyslexic adolescents were demonstrated to be more creative in terms of flexibility and fluidity than their non-dyslexic peers. Subjectively, while viewing the Magritte paintings, dyslexics reported fewer conceptual spaces and fewer hidden words than their non-dyslexic peers; thus, they confabulated less than non-dyslexics. Dyslexics also demonstrated an abnormal oculomotor profile similar to those that we have shown when reading, viewing randomized targets, and while perceiving illusions of depth in Op art paintings, in that they demonstrated difficulty with disconjugation and abnormalities in their eye velocity profiles. We propose there may be a link between dyslexic increased creativity and their eye movement abnormalities. Similar to reading nonsense text, we propose that Magritte’s contradictory paintings exacerbate dyslexics’ eye movement abnormalities. These eye movement abnormalities while viewing these particular paintings might provide a physiological signature suggesting a contribution of their unusual eye control to their higher creativity scores.