Various extrinsic issues in the auditory N100 component

Influence of segmental sounds on the N100 component

Abstract

The objective of this paper is to clarify the influence of extrinsic factors of a sound type in speech sound on the N100 component upon ERP study with speech sound as auditory stimulation.

In Experiment 1, the difference in the influence on the N100 component between speech sound and pure sound was verified. Regarding pure sound, we also allowed the sound immediately after trigger and the delayed sound to be heard, to verify the influence of delay. In Experiment 2, we verified the influence of aspirated/unaspirated and VOT/-VOT in voiceless unaspirated plosives [p], voiceless aspirated plosives [pʰ], and voiced plosives [b]. In Experiment 3, the influence of strident was verified in voiceless plosives [p] [t] [k], voiceless affricates [ts], and voiceless fricatives [s].

The results are as follows. (1) In speech sound, the onset time of vowel formant frequency relates to induction of the N100 component. (2) The N100 component is induced with a delay due to the silent section with VOT. (3) The N100 component is induced with a delay with -VOT. (4) The peak voltage in the N100 component is reduced by the noise in [s] in fricatives.

It was suggested in the above influence that further verification is necessary on control of conditions in the ERP study of a language by using MMN, P300, N400, P600, etc.