However, more subtle and sophisticated techniques, such as voxel-based morphometry studies have allowed researchers to identify bilateral abnormalities in neural volume in areas of the brain associated with motor functions, such as the caudate nucleus, in the affected members of the KE family when compared to the unaffected family members. This volume reduction showed a high correlation between reduced volume and tests of oral praxis, supporting the idea that odd development of the caudate nucleus is related to the problems in motor control observed in the KE family.Due to the vague nature of the diagnosis of expressive language disorder, there is little specific scientific research that we can currently locate. A larger body of research exists around neuroscientific studies with children diagnosed with a specific language impairment (SLI). fMRI studies have shown that children with SLI have a significantly smaller left hemispheric pars triangularis (Brocas area) and asymmetry of dominance of language structures, as opposed to the more typical left hemisphere dominance. Scientists are beginning to elucidate differences in activation patterns in children with SLIs using neuroimaging techniques to capture brain activity while performing different cognitive tasks. A major observation is lack of left hemisphere lateralization in major language structures such as the inferior frontal gyrus-opercularis, inferior frontal gyrus-triangularis, supramarginal gyrus and superior temporal gyrus. The same study reported hypoactivation and hyper activation of other brain regions - the supramarginal junction and anterior insula, respectively. Other in-depth imaging studies report finding previously undiagnosed lesions in the brains of children with well-characterized developmental language development.
Together, these findings strongly suggest that language impairments are the result of an underlying neurological defect in an area of the brain related to language. Studies looking at long-term outcomes for individuals with specific language impairments such as expressive language disorder track these individuals from childhood to adulthood. As Whitehouse and his colleagues  suggest, "When childhood language problems persist into adulthood, they can have far reaching consequences in terms of academic, social and vocational outcomes." These researchers found that children diagnosed with an SLI would have persistent problems with language and are more likely to pursue vocational training rather than university, thereby avoiding professions requiring high levels of literacy. A lower socioeconomic status was also noted by adults who were diagnosed with an SLI as a child. Whitehouse  also reported that these adults had more difficulties in establishing friendships, most likely due to a decreased ability to express themselves socially. Current educational interventions for students with an SLI
Specific language impairments are often secondary characteristics of other disorders such as autism spectrum disorder and attention deficit hyperactivity disorder. In these cases, issues with speech and language are often not treated specifically, but rather attention is given to the primary complaint. Due to the high correlation of an SLI with other disorders, it is difficult to tell the difference between "pure SLI" or language impairments due to the presence of another disorder. See also
Auditory processing disorder
Speech-Language Pathology
Mixed receptive-expressive language disorder

References
Further reading
Bacon C, Rappold GA (November 2012).