Principles of success and failure in reading instruction via the lens of systems neuroscience. McCandliss, Sackler Inst- Weill Med. Col The basic heft of this talk was to present evidence for enhanced visual abilities in dyslexic individuals. The background for this student is two-fold. First, that the parents of many dyslexic school children has claimed for many years that their children are endowed with enhanced visual abilities of one flavor or another. Researchers have been moderately dismissive of these claims (at least according to the speaker), but recently have attempted to directly test these claims. One study showed Escher figures to individuals and quantified the speed with which the subjects could distinguish between possible and impossible structures. The results showed that dsylexics can identify/analyze Escher figures twice as fast as non-dyslexics.
Jumping off from this finding, the researchers looked at dyslexic astrophysicists. A common task in the field of astrophysics is black hole detection. This task , involves identifying patterns amongst a complex field. The researchers hypothesized that dyslexics would have heightened sensitivity for pattern detection across a wide visual field. This is in part based on previous results showing that dyslexics are less able to detect patterns in the foveal receptive fields. The results were that dyslexic astrophysicists are remarkably superior at detecting black holes, showing a significant increase in signal-to-noise threshold at periphery of visual field.
Next, the researchers expanded to wider population, asking students to detect a letter hidden in a photograph. Dyslexic students showed heightened ability to detect the hidden letter - this suggests to the researchers that dsylexics have a differently constructed visual system. The speaker concludes his talk with the comment that they have no idea where the difference is (retina versus cortex versus any other visual-associated brain region).
A question from the audience: what about neurologists who have to read EEG’s, X-rays, or fMRI. The speaker suspects that dyslexics would also be better at pattern detection in these cases than non-dyslexics.
Another question: Are the differences in eye-scanning during reading of dyslexics accounted for by the lower power of the retina to detect patterns and the concomitant increase in peripheral pattern detection capabilities? Answer: possibly, although they have not done the research.