title: Delayed magnetic mismatch negativity field, but not auditory M100 response, in specific language impairment.
abstract: Recent studies show that electrophysiological markers of auditory processing such as the cortical 100 ms response (M100) and the mismatch field, derived from magnetoencephalography, might be used to identify children with autism spectrum disorders--M100 peak latency--and to stratify children with autism according to the degree of language impairment--mismatch field peak latency. The present study examined the latency of right superior temporal gyrus M100 and mismatch field in a cohort of children and young adolescents with specific language impairment (n=17), in comparison with age-matched and nonverbal intelligence quotient-matched typically developing controls (n=21). Neither group showed symptoms associated with autism. Although M100 latency (reflecting early auditory processing) did not distinguish controls from children with specific language impairment, the later 'change detection' mismatch field response was significantly delayed (by >50 ms) in the specific language impairment group. Linear discriminant analysis confirmed the role of mismatch field latency (92%) but not M100 latency (8%) in distinguishing groups. The present results lend support to the claim that a delayed M100 is specific to autism spectrum disorders (with relative independence of degree of language impairment) and that a delayed mismatch field reflects an abnormality more generally associated with language impairment, suggesting that mismatch field delay in the present specific language impairment group and previously reported in autistic children with language impairment may be indicative of a common neural system dysfunction.
authors.affiliation: Department of Radiology, Children's Hospital of Philadelphia, Wood Bldg. Suite 2115, 34th St, Philadelphia, PA 19104, USA. robertstim@email.chop.edu
authors.forename: Timothy P L
authors.initials: TP
authors.lastname: Roberts
authors.forename: Kory
authors.initials: K
authors.lastname: Heiken
authors.forename: Sarah Y
authors.initials: SY
authors.lastname: Kahn
authors.forename: Saba
authors.initials: S
authors.lastname: Qasmieh
authors.forename: Lisa
authors.initials: L
authors.lastname: Blaskey
authors.forename: Cynthia
authors.initials: C
authors.lastname: Solot
authors.forename: William Andrew
authors.initials: WA
authors.lastname: Parker
authors.forename: Ragini
authors.initials: R
authors.lastname: Verma
authors.forename: James Christopher
authors.initials: JC
authors.lastname: Edgar
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D001307:Auditory Perception / Q000502:physiology; D016009:Chi-Square Distribution; D002648:Child; D003265:Contingent Negative Variation / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D007805:Language Development Disorders / Q000473:pathology / Q000503:physiopathology*; D016014:Linear Models; D015225:Magnetoencephalography; D008297:Male; D011930:Reaction Time / Q000502:physiology