This is from a paper by Torrey Loucks written in 2011 Corpus callosum differences associated with persistent stuttering in adults Recent studies have implicated anatomical differences in speech-relevant brain regions of adults who stutter (AWS) compared to normally fluent adults (NFA). The present study focused on the region of the corpus callosum (CC) which is involved in interhemispheric processing between the left and right cerebral hemispheres. Two-dimensional segmentation of area and voxel-based morphometry were used to evaluate the corpus callosum. Results revealed that the rostrum and anterior midbody of the CC were larger in AWS than NFA. In addition, the overall callosa area was larger in AWS than NFA. The group comparison of white matter volume showed a cluster of increased white matter volume predominantly encompassing the rostrum across the midline portion in AWS. These results potentially reflect anatomical changes associated with differences in the hemispheric distribution of language processes that have been reported previously in AWS. Left-handed or ambidextrous individuals also possess a larger callosa compared to right-handed individuals (Witelson, 1985). Children with developmental language disorder which is typically associated with left hemisphere damage or deficit also feature a larger anterior and middle callosa compared to typically developing children (Preis, Steinmetz, Knorr & Jäncke, 2000;Shields, Varley, Broks & Simpson, 1996). Similarly, a left hemisphere deficit or dysfunction albeit mild may also be present in developmental stuttering and potentially result in greater right hemisphere participation and consequently, a larger CC in AWS.