Steady-state MEG responses elicited by a sequence of amplitude-modulated short tones of different carrier frequencies.

In this study, we examined magnetoencephalographic (MEG) ASSR using a sequence of sinusoidal AM tones of 0.78 s in length with various tone frequencies of 440-990 Hz in about one octave variation. It was found that the amplitude of the ASSR was invariant with tone frequencies when the level of sound pressure was adjusted along an equal-loudness curve. The amplitude also did not depend on the existence of preceding tone or difference in frequency of the preceding tone. When the sound level of AM tones was changed with tone frequencies in the same range of 440-990 Hz, the amplitude of ASSR varied in a proportional manner to the sound level. These characteristics are favorable for the use of ASSR in studying temporal processing of auditory information in the auditory cortex. The lack of adaptation in the ASSR elicited by a sequence of short tones may be ascribed to the neural activity of widely accepted generator of magnetic ASSR in the primary auditory cortex.
PMID: 23174483 [PubMed - as supplied by publisher]

Source: Hearing Research - November 19, 2012 Category: Audiology Authors: Kuriki S, Kobayashi Y, Kobayashi T, Tanaka K, Uchikawa Y Tags: Hear Res Source Type: research