title: Distinctive MMN relative to sound types in adults with intellectual disability.
abstract: The effect of stimulus characteristics (vowel vs pure tone) upon mismatch negativity (MMN) was compared between adults with intellectual disability and healthy controls. Either vowels (synthesized vowels /e/ and /o/) or pure tones (1940 and 851 Hz corresponding to the F2 frequencies of /e/ and /o/, respectively) were presented using an oddball procedure. Both groups showed identical results in latency (vowel MMN>pure tone MMN) and less amplitudes for vowels. However, the disabled group demonstrated amplitude attenuation regardless of the stimulus type, although the vowel MMN amplitude showed a descending trend with age in both groups. These results suggest that auditory sensory memory in intellectual disability might have an insufficient capacity yet share a property common to controls.
authors.affiliation: Research Institute for Education of Exceptional Children, Tokyo Gakugei University, Koganei, Tokyo 184-8501, Japan. kazunari@u-gakugei.ac.jp
authors.forename: Kazunari
authors.initials: K
authors.lastname: Ikeda
authors.forename: Akiko
authors.initials: A
authors.lastname: Hayashi
authors.forename: Souichi
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kanno
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D001307:Auditory Perception / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000503:physiopathology*; D007361:Intelligence Tests / Q000706:statistics & numerical data; D008297:Male; D011930:Reaction Time / Q000502:physiology*