Symposium: Clinical applications: hearing and speech disorders
Wednesday, Sep 9, 2015
Magnetoencephalographic correlates of auditory processing from tones to words: contributions to clinical language impairment
Children’s Hospital of Philadelphia, University of Pennsylvania, United States
Auditory processing deficits, and the consequent degradation of auditory sensory input may underlie ineffective higher order processing with subsequent impairment of language function. This is particularly significant in pediatric populations as language acquisition occurs at young age, and anomalies may not be appreciated during time-periods critical for effective interventions.
Results will be presented from studies of language impairment in autism spectrum disorder across developmental age range. Using MEG, discussion will focus on the magnetic analog of the MMN, termed mismatch field (MMF). Prior literature in this area has been discordant, in apart due to methodological differences, but primarily associated with the vast heterogeneity of the ASD population, and insufficient sample size to power statistical inferences. MMF results will be discussed in terms of simpler auditory evoked responses, as well as related priming paradigms (for which change detection is also reflected in electrophysiological signals). Moreover, sample sizes exceed 100 and thus begin to address the heterogeneity-related inconsistencies in the literature. Sensitivity of the MMF delays, independent of etiology, is demonstrated by inclusion of a comparison cohort with specific language impairment (SLI). Correlations with clinical language function assessed e.g. with eth CELF-4/CELF-5 measures are also presented.
Extension of these methods to much younger populations (6-48months) through dedicated MEG hardware, and less compliant populations (including minimally-verbal low functioning children) through combined behavioral/technical approaches will be discussed.