Eight dyslexic subjects, aged 20 +/-0.9 years, university students who were impaired on measures of reading, spelling and naming speed, matched for age and general ability with 10 control subjects, were scanned using PET while reading words and naming pictures, in a study at the Institute of Psychiatry, University College, and the Institute of Neurology, London, UK. Dyslexic subjects showed reduced activation in a left occipitotemporal area during both word reading and picture naming. The findings point to a common neurological basis for deficits in word reading and picture naming in developmental dyslexia. [1]
COMMENT. Previous studies have demonstrated abnormal activation of the left occipitotemporal area during word processing in dyslexia [2, 3]. Children learn to name pictures of objects before they can read. The above UK study shows that an area of the brain involved in word reading is also activated in picture naming. The authors propose that the diagnosis and treatment of a delay in picture naming skills in preschool children may influence the later acquisition of reading performance.