Friday, October 19, 2007

The second brain paper

The second article is now in press at NeuroImage. The main author is Soo-Eun Chang, a post-doc in Christy Ludlow's group at NIH (National Institute of Health) in Bethesda close to Washington DC. She is a speech and language pathologist by training. I had the pleasure to meet up with her and Christy for lunch on Wednesday before I took the plane back to Old Europe. Our discussion topics included their work and stuttering medication.

Here is their abstract of Brain anatomy differences in childhood stuttering by Soo-Eun Chang, Kirk I. Erickson, Nicoline G. Ambrose, Mark A. Hasegawa-Johnson, and Christy L. Ludlow:
Previous imaging studies in adults with persistent stuttering found left white matter deficiencies and reversed right-left asymmetries compared to fluent controls. We hypothesized that similar differences might be present indicating brain development differences in children at risk of stuttering. Optimized voxel-based morphometry compared gray matter volume (GMV) and diffusion tensor imaging measured fractional anisotropy (FA) in white matter tracts in 3 groups: children with persistent stuttering, children recovered from stuttering, and fluent peers. Both the persistent stuttering and recovered groups had reduced GMV from normal in speech-relevant regions: the left inferior frontal gyrus, and bilateral temporal regions. Reduced FA was found in the left white matter tracts underlying the motor regions for face and larynx in the persistent stuttering group. Contrary to previous findings in adults who stutter, no increases were found in the right hemisphere speech regions in stuttering or recovered children and no differences in right-left asymmetries. Instead, a risk for childhood stuttering was associated with deficiencies in left gray matter volume while reduced white matter integrity in the left hemisphere speech system was associated with persistent stuttering. Anatomical increases in right hemisphere structures previously found in adults who stutter may have resulted from a life-time of stuttering. These findings point to the importance of considering the role of neuroplasticity during development when studying persistent forms of developmental disorders in adults.


Anonymous said...

Interesting read...

So, now is it a matter of finding something to help grow that white matter, specific to those regions?

Ritalin stimulates white brain matter growth...


Anonymous said...

This paper is available in manuscript form on the NeuroImage website. A complete and thorough read reveals a very strong methodology with well recognized limitations by the authors. Paediatric templates appropriate to age of participants are used for statistical analysis. Replication of the previous two DTI results is encouraging espcially in this younger cohort. Interstingly, the grey matter differences are not the same as those found in adult studies and this is suggestive of compensatory changes in brain structure. This study lays the groundwork for future studies using neuroimaging in school-age and preschool children. Kudos to the authors.

Anonymous said...


Are you serious about Ritalin?

I find that it does improve my fluency.

Silent P.

Simona said...

Hi Silent P:

I didn't mean to infer in absolute there. I read this on an website:

" some evidence suggests that Ritalin may help increase white matter (the primary substance that makes up the core of the brain's hemispheres). "

and it was in reference to the long term complications which that section seems to refute.

But, now that we have more data on which part of the brain is under-performing, I would love to see white matter enhancers targeting those very specific parts of the brain.

FYI - for people who don't know a lot about neuroscience (including me!) - the grey matter is the part of the brain that does the thinking... and the white matter is the part that is doing the connecting.

So it seems to me that stutterers have the physical ability to articulate speech (thanks to grey matter), but it's the white matter function of timing and coordination of motor function that our brain seems to get tripped up on.

Also, just a side note: the U.S. National Institute of Health ( officially calls the motor function error in stuttering Neurogenic Stutering... and they say Developmental Stuttering is when a child is searching for the right word (his mental ability exceeds his verbal ability). According to them, Developmental Stuttering is usually outgrown in childhood.

So... should we be using the PDS term to describe most of our stuttering--when Neurogenic Stuttering is probably more accurate?