Less brain tissue not behind reading disorder
In people with dyslexia, less grey matter in the brain has been linked to reading disabilities, but new evidence suggests this is a consequence of poorer reading experiences and not the root cause of the disorder.
A study compared a group of dyslexic children with two different control groups - an age-matched group included in most previous studies, and a group of younger children who were matched at the same reading level as the children with dyslexia.
"This kind of approach allows us to control for both age as well as reading experience," explained neuroscientist Guinevere Eden, professor of paediatrics at Georgetown University Medical Centre (GUMC).
"If the differences in brain anatomy in dyslexia were seen in comparison with both control groups, it would have suggested that reduced grey matter reflects an underlying cause of the reading deficit. But that's not what we observed," Eden said.
The dyslexic groups showed less grey matter compared with a control group matched by age, consistent with previous findings, said the study published in the Journal of Neuroscience.
However, the result was not replicated when a control group matched by reading level was used as the comparison group with the dyslexics.
"This suggests that the anatomical differences reported in left hemisphere language processing regions appear to be a consequence of reading experience as opposed to a cause of dyslexia," said Anthony Krafnick, lead author of the publication.
"These results have an impact on how we interpret the previous anatomical literature on dyslexia and it suggests the use of anatomical MRI would not be a suitable way to identify children with dyslexia," Krafnick added.
The work also helps to determine the fine line between experience-induced changes in the brain and differences that are the cause of cognitive impairment.
(Posted on 14-01-2014)
Information on States of India:
Andaman Nicobar | Andhra Pradesh | Arunachal Pradesh | Assam | Bihar | Chandigarh | Chhattisgarh | Dadar Nagar Haveli | Daman Diu | Delhi | Goa | Gujarat | Haryana | Himachal Pradesh | Jammu Kashmir | Jharkhand | Karnataka | Kerala | Lakshadweep | Madhya Pradesh | Maharashtra | Manipur | Meghalaya | Mizoram | Nagaland | Orissa | Pondicherry | Punjab | Rajasthan | Sikkim | Tamil Nadu | Tripura | Uttar Pradesh | Uttaranchal | West Bengal
INDIA REGIONAL MAPS:
Andhra Pradesh Travel Map | Bihar Travel Map | Goa Travel Map | Gujarat Travel Map | Haryana Travel Map | Himachal Pradesh Map | Karnataka Travel Map | Kerala Travel Map | Maharashtra Travel Map | Punjab Travel Map | Rajasthan Travel Map | Sikkim Travel Map | Tamil Nadu Travel Map | Uttar Pradesh Travel Map | West Bengal Travel Map |
KERALA TRAVEL MAPS:
TRAVEL MAPS OF INDIA:
INDIA CITY MAPS: