Delayed automatic detection of change in speech sounds in adults with autism: a magnetoencephalographic study.
OBJECTIVE
Autism is a form of pervasive developmental disorder in which dysfunction in interpersonal relationships and communication is fundamental. This study evaluated neurophysiological abnormalities at the basic level of language processing, i.e. automatic change detection of speech and non-speech sounds, using magnetoencephalographic recording of mismatch response elicited by change in vowels and tones.


METHODS
The auditory magnetic mismatch field (MMF) was evaluated in 9 adults with autism and 19 control subjects using whole-head magnetoencephalography. The MMF in response to the duration change of a pure tone or vowel /a/ and that in response to across-phoneme change between vowels /a/ and /o/, were recorded.


RESULTS
The groups were not significantly different in MMF power under any conditions. However, the autism group showed a left-biased latency prolongation of the MMF particularly under the across-phoneme change condition, and this latency delay was significantly associated with greater symptom severity.


CONCLUSIONS
These results suggest that adults with autism are associated with delayed processing for automatic change detection of speech sounds. These electrophysiological abnormalities at the earliest level of information processing may contribute to the basis for language deficits observed in autism.


CONCLUSIONS
These results provide the first evidence for delayed latency of phonetic MMF in adults with autism.
Kasai
Kiyoto
K
Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan. kasaik-tky@umin.ac.jp
Hashimoto
Ohiko
O
Kawakubo
Yuki
Y
Yumoto
Masato
M
Kamio
Satoru
S
Itoh
Kenji
K
Koshida
Ichiro
I
Iwanami
Akira
A
Nakagome
Kazuyuki
K
Fukuda
Masato
M
Yamasue
Hidenori
H
Yamada
Haruyasu
H
Abe
Osamu
O
Aoki
Shigeki
S
Kato
Nobumasa
N
D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000503:physiopathology; D001304:Auditory Diseases, Central / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D001308:Auditory Perceptual Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D001321:Autistic Disorder / Q000503:physiopathology* / Q000523:psychology; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007805:Language Development Disorders / Q000209:etiology / Q000503:physiopathology* / Q000523:psychology; D007807:Language Tests; D015225:Magnetoencephalography; D008297:Male; D011930:Reaction Time / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*