Auditory evoked M100 reflects onset acoustics of speech sounds

Magnetoencephalography (MEG) was used to investigate the response to speech sounds that differ in onset dynamics, parameterized as words that have ini tial stop consonants (e.g., /b/, /t/) or do not (e.g., /m/, /f/). Latency a nd amplitude of the M100 auditory evoked neuromagnetic field, recorded over right and left auditory cortices, varied as a function of onset: stops had shorter latencies and higher amplitudes than no-stops in both hemispheres, consistent with the hypothesis that M100 is a sensitive indicator of spect ral properties of acoustic stimuli. Further, activation patterns in respons e to stops/no-stops differed in the two hemispheres, possibly reflecting di fferential perceptual processing for the acoustic-phonetic cues at the onse t of spoken words. (C) 1998 Elsevier Science B.V. All rights reserved.