权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Investigation for the activation mechanism of deep brain structures caused by high frequency components above the audible range

高于可听范围的高频成分引起脑深部结构激活机制的研究

基本信息

批准号：
09490031
负责人：
OOHASHI Tsutomu
金额：
$ 8万
依托单位：
Chiba Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Although it is generally accepted that humans cannot perceive sounds in the frequency range above 20 kHz, the question of whether the existence of such "non-audible" high-frequency components may affect the acoustic perception of audible sounds remains unanswerd. Using Noninvasive physiological measurements of brain responses, we provide evidence that sounds containing high-frequency components (HFC) above the audible range is significantly affect the brain activity of listeners. We used the gamelan music of Bali, which is extremely rich in HFC with a nonstationary structure, as a natural sound source, dividing it into two components: an audible low-frequency component (LFC) below 22 kHz and a HFC above 22 kHz. Brain electrical activity and regional cerebral blood flow (rCBF) were measured as markers of neuronal activity while subjects were exposed to sounds with various combinations of LFC and HFC.None of the subjects recognized the HFC as sound when it was presented alone. Neverthele … More ss, the power spectra of the alpha frequency range of the spontaneous electroencephalogram (alpha-EEG) recorded from the occipital region increased with statistical significance when the subjects were exposed to sound which contained both HFC and LFC, compared with an otherwise identical sound from which the HFC was removed (I.e., LFC alone). In contrast, compared with the baseline, no enhancement of alpha-EEG was evident when either HFC or LFC was presented separately. PET measurements revealed that, when HFC and LFC were presented together, the rCBF in the brainstem and the left thalamus increased significantly compared with an otherwise identical sound except Jacking the HFC above 22 kHz. Simultaneous EEG measurements showed that the power of occipital alpha-EEGs correlated significantly with the rCBF in the left thalamus. Psychological evaluation indicated that the subjects felt the sound containing HFC to be more pleasant than the same sound lacking HFC.These results suggest the existence of a previously unrecognized response to complex sound containing particular types of high frequencies above the audible range. We term this phenomenon the "hypersonic effect". Less

虽然人们普遍认为人类无法感知20 kHz以上频率范围内的声音，但这种“不可闻”高频分量的存在是否会影响可听声音的声学感知的问题仍然没有答案。使用非侵入性的大脑反应的生理测量，我们提供的证据表明，包含高于可听范围的高频成分（HFC）的声音显着影响听者的大脑活动。我们使用巴厘岛的加麦兰音乐作为自然声源，它含有非常丰富的HFC，具有非平稳结构，将其分为两个分量：低于22 kHz的可听低频分量（LFC）和高于22 kHz的HFC。脑电活动和局部脑血流量（rCBF）被测量为神经元活动的标志，而受试者暴露于各种组合的LFC和HFC的声音。内瑟莱 ...更多信息 ss，当受试者暴露于包含HFC和LFC的声音时，与去除HFC的其他相同声音相比，从枕区记录的自发脑电图（alpha-EEG）的α频率范围的功率谱以统计学显著性增加（即，LFC单独）。相比之下，与基线相比，当HFC或LFC单独呈现时，α-EEG没有明显增强。PET测量结果显示，当HFC和LFC一起出现时，与除将HFC提升到22 kHz以上之外的其他相同声音相比，脑干和左丘脑中的rCBF显著增加。同步EEG测量显示，枕叶α-EEG的功率与左侧丘脑的rCBF显著相关。心理评估表明，受试者感觉含有HFC的声音比不含HFC的相同声音更悦耳。这些结果表明，对包含可听范围以上特定类型高频的复杂声音存在以前未识别的反应。我们称这种现象为“高超音速效应”。少