Steady-state MEG responses elicited by a sequence of amplitude-modulated short tones of different carrier frequencies
Steady-state MEG responses elicited by a sequence of amplitude-modulated short tones of different carrier frequencies
复制标题
DOI：
10.1016/j.heares.2012.11.002
复制
发表时间：
2013-02-01
期刊：
影响因子：
2.8
通讯作者：
Uchikawa, Yoshinori
中科院分区：
文献类型：
--
作者：
Kuriki, Shinya;Kobayashi, Yusuke;Uchikawa, Yoshinori
听觉稳态反应（ASSR）是由周期性声刺激引起的一种微弱的电位或磁反应，其最大反应周期约为40 Hz。在大多数以前的研究中，使用调幅（AM）音的刺激声音，长持续的音调长度超过10秒。然而，由短AM音引起的ASSR的特征仍然不清楚。在这项研究中，我们检查脑磁图（MEG）ASSR使用一系列的正弦调幅音的长度为0.78秒，各种音调频率为440-990赫兹，约一个倍频程的变化。结果发现，当声压水平沿沿着等响曲线调节时，ASSR的幅值不随音调频率变化。振幅也不依赖于前一个音的存在或前一个音的频率差异。在440-990 Hz范围内，AM音的声级随音频变化时，ASSR的幅值与声级成正比。这些特点为ASSR研究听觉皮层听觉信息的时间加工过程提供了有利条件。短音序列引起的ASSR缺乏适应性可能归因于初级听觉皮层中广泛接受的磁ASSR发生器的神经活动。(C)2012爱思唯尔有限公司版权所有。
The auditory steady-state response (ASSR) is a weak potential or magnetic response elicited by periodic acoustic stimuli with a maximum response at about a 40-Hz periodicity. In most previous studies using amplitude-modulated (AM) tones of stimulus sound, long lasting tones of more than 10 s in length were used. However, characteristics of the ASSR elicited by short AM tones have remained unclear. 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. (C) 2012 Elsevier B.V. All rights reserved.