They cannot therefore be regarded as typical cases of SLI, though many features of their phenotype resemble features seen in SLI. Affected Pexidartinib members of the KE family have a verbal dyspraxia evident on tests of nonword repetition and oromotor praxis. In addition, as a group they show impairments on many other tests of language and, in some cases, nonverbal cognition (Watkins, Dronkers, & Vargha-Khadem, 2002a). Imaging studies reveal reduced volume of the caudate nucleus, increased grey matter in the left inferior frontal gyrus and posterior temporal cortex in affected family members (Belton et al., 2003 and Watkins et al., 2002b). Functionally, the caudate nucleus is overactive during speech GW 572016 production
(Watkins, Gadian, & Vargha-Khadem, 1999), whereas the left inferior frontal gyrus and posterior language cortex are underactive (Liégeois et al., 2003). The volume of the caudate nucleus was
found to correlate with performance on tests of nonword repetition and oral praxis (Watkins et al., 2002b). Given the phenotypic similarities between the KE family and more typical SLI, it is of interest to compare brain structure and function of these groups. Here, we used magnetic resonance imaging (MRI) to investigate brain structure and function in a group of 10 individuals with SLI ranging in age from 8 to 17 years. We compared their data with that obtained in six unaffected siblings, who tended to be older than the SLI group (age range 12–22 years), and a group of 16 unrelated controls with typical language development who were matched in age as closely as possible to the participants from the SLI
group and their siblings (6–25 years). Three of the SLI group and two of the unaffected siblings and unrelated control groups were left-handed; all other participants were right-handed. The task used for the fMRI scan was a modified version of an auditory response-naming task (Bookheimer et al., 1998) that reliably activates left inferior Florfenicol frontal cortex (Broca’s area) and posterior superior temporal cortex (Wernicke’s area). The aims of the study were to characterise the brain abnormalities associated with SLI and to determine whether previously described functional and structural abnormalities were related. Participants were recruited through a research participant database of families with at least one child with SLI and families with typically-developing children who had participated in previous studies (Barry et al., 2007 and Barry et al., 2008). Participants were required to have normal hearing (a bilateral pure tone audiometric screening test at 25 db HL ISO for 500, 1000, and 2000 Hz), a non-verbal IQ (NVIQ) score of 80 or above on the Wechsler Abbreviated Scale of Intelligence (Wechsler & Chen, 1999), English as their first language, and no reported neurological impairments.