Inside Read3 Journal Club
The one where they tackled statistical learning
By Read3 Consulting Speech Pathologist, Helen Dimond
We buckled in recently at the Read3 Journal Club for Speech Pathologists and tackled the topic of statistical learning and its possible connection to dyslexia. Typically the articles chosen for Journal Club are Meta Analyses, so we decided to mix things up this time by selecting a Review. The article chosen was a 2021 review by Singh and Conway.
What is statistical learning?
Statistical learning is like your brain's secret code-breaking ability. It's how we pick up on patterns in our environment, from the sounds of language to the order of letters in words. It’s a domain general cognitive skill, which for the non-Psychologists amongst us means it’s a skill that is broadly applicable across tasks (other examples are language skills and executive function). So statistical learning isn’t just necessary for reading, it’s also important for maths, visual perception, music, social cognition and so on.
How does it fit with dyslexia?
The 2021 article examined several dozen studies, released between 2014 and 2021, with a view to exploring whether there is a link between dyslexia and statistical learning.
Across the studies, statistical learning was measured using a range of different tasks, targeting a range of different functions, which makes direct comparisons more difficult.
Based on the research presented in this review, the consensus was mixed.
However, once the article was evaluated using TREAT Journal Club appraisal tools, the methods of article selection, and lack of statistical analysis, led us to define this article as more of a qualitative discussion than a systematic review.
At Read3, we like a bit of hard-core data around our claims. Therefore, while the chosen article was an interesting read, if you're looking for some statistical rigour on this topic we would refer you to the 2022 meta analysis by Lee et al which confirmed individuals with developmental dyslexia exhibited a significant moderate weakness in statistical learning. We encourage you to take a look at this particular article if you’re after some more detail.
The discrepancies between these two articles demonstrate two things:
- the need to be critical of the methodology of each journal article we read (and indeed the individual articles within a review)
- that there is still plenty of research to be done in the mystical space of dyslexia and statistical learning
Singh and Conway's 2021 article makes mention of a range of different theories of dyslexia (some of which are quite controversial and haven’t led to substantial gains in terms of diagnosis or intervention).
It's important to note that the focus of a study may be shaped by the dyslexia theory that underpins it, and therefore it is difficult to compare the findings.
A few highlights: some really interesting studies…
Despite the qualitative nature of this particular Journal Club article (and mixed results about the link between statistical learning and dyslexia) there were some interesting findings within the 14 studies that involved children. We have, of course, viewed these from the lens of teaching literacy.
- One study reported that children with dyslexia do learn the tasks but it takes longer, and requires a higher number of repetitions. This is a good reminder of the need to ensure adequate time is given to the “essentials” – like mastering letter-sound links for example.
- Similarly, despite initial poor learning for those with dyslexia, once learned retention was comparable to typical learners. A reminder that mastery matters!
- Another study showed that while no learning impairments were observed, children with dyslexia exhibited slower response times and lower accuracy overall. This has implications for how we teach new concepts, check for understanding and consolidate learning.
- More broadly, those with dyslexia were more likely to perform similarly to typical readers if the statistical learning tasks were taught explicitly rather than implicitly. This is a strong reminder of the importance of explicit instruction in all learning.
- Performance differed between studies that looked at overnight consolidation versus those that didn’t. For thirty years we’ve known that sleep is when the neurophysiology of learning is ‘laid down’ so resolving sleep problems for kids with learning issues needs to be a priority.
How does this pertain to students we are working with?
I think it’s fair to say that statistical learning is complex! Gaining some level of understanding of the impact of ‘domain general’ cognitive skills, like statistical learning and executive function certainly deepens our understanding of the rich tapestry of learning difficulties.
The children you are working with are most likely struggling with a number of cognitive processes. Some may fall outside the realm of what you are able to assess but knowing ‘where else to look’ may be useful.
While this particular review didn’t provide all the answers we seek in relation to dyslexia and statistical learning, it certainly provides some food for thought.
We look forward to reading more research into this fascinating area of statistical learning.
If you have any comments, please share below. 😊
Articles:
Singh, S., and Conway, C. (2021). Unravelling the Interconnections Between Statistical Learning and Dyslexia: A Review of Recent Empirical Studies. Cognitive Neuroscience, Volume 15 - 2021.
Lee, S., Cui, Y., & Tong, S. X. (2022). Toward a Model of Statistical Learning and Reading: Evidence From a Meta-Analysis. Review of Educational Research. 92.