According to researchers, right hemisphere parts of the brains of people with dyslexia have been shown to differ from those of normal readers.
To compare the two groups, the researchers used magnetic resonance imaging (MRI) and were able to associate the neurological differences found with different language difficulties within the dyslexic group.
Cyril Pernet and team from the University of Edinburgh compared the brains of 38 people with dyslexia to a model typical brain created by combining the scans of 39 normal readers. They found the differences in either the right cerebellar declive or the right lentiform nucleus in all subjects. These were linked to varying performance in language tests.
It is known fact that dyslexia is not a unique entity, but might reflect different neuro-cognitive pathologies. Earlier studies tried ways to distinguish between different types of dyslexia for several years, but this study is among the first to show a direct link between brain structure and symptom severity. According to Pernet, These results provide evidence for the existence of various subtypes of dyslexia characterized by different brain phenotypes. In addition, behavioral analyses suggest that these brain phenotypes relate to different deficits of automatization of language-based processes such as grapheme/phoneme correspondence and/or rapid access to lexicon entries.