Developmental dyslexia is cited as an example of a developmental disorder with unclear etiology, sometimes associated with abnormalities in which hemisphere?

• A. Left hemisphere
• B. Right hemisphere
• C. Both hemispheres
• D. Occipital lobe

Answer: (A)

Developmental dyslexia involves difficulties with reading that stem from language-related processing rather than basic vision. Reading relies on left-hemisphere networks that handle phonological processing and mapping sounds to letters. Abnormalities in these left-hemisphere regions, particularly in the temporoparietal area and the left occipitotemporal region (which includes the visual word form area), are the most consistently observed neural differences in dyslexia. This left-sided involvement aligns with the phonological decoding deficits that are central to the disorder. While research explores other regions and factors, the strongest and most replicable associations are with left-hemisphere abnormalities, rather than the right hemisphere or the occipital lobe alone.