Human Evoked Response and EEG Changes to Odorant Stimulation

本文概述了我们在1987-1988年间的研究结果。开发了一种设备，允许控制刺激，以记录来自人类头皮的气味诱发反应。该装置的特点如下。1)鼻孔上连接了一个传感器，可以将受试者的呼吸转化为电信号。2)气味刺激的周期和时机是可调的，可以与呼吸同步给予刺激。3)气味刺激的间隔可以任意选择，每隔1到9次呼吸(S)，以避免对给定气味的适应。在26名正常受试者中，84.6%的人获得了刺激性诱发反应。响应分为三种类型，峰值潜伏期为300毫秒、700毫秒，两者均为潜伏期。头皮反应的分布表明，高电位区广泛分布在顶端，并且潜伏期随着距离枕区的增加而增加。没有记录到嗅觉障碍患者的反应。然而，这一发现还需要更多的研究来应用到客观嗅觉测量中，因为并不是所有的正常受试者都记录到了反应。结果表明，枕区α_1波、Delta波和Rheta波减少，额区α_2波增加。这些脑电变化可能反映了额区嗅觉中枢系统的活动。

The summary of the results of our study which took place from 1987 to 1988 are described. An apparatus was developed allowing control of stimulation for recording odorant evoked response from the human scalp. The characteristics of the apparatus were as follows. 1) A sensor was attached to the nostril allowing translation of the subject's respiration into electrical signals. 2)The period and timing of odorant stimuli were adjustable allowing stimuli to be given synchronous with respirations. 3)The intervals of odorant stimulation could be arbitrarily selected to occur every 1 to 9 respiration(s) allowing avoidance of adaptation to the given odor.Odorant evoked responses were obtained in 84.6% of the 26 normal subjects tested. The responses were classified into three types, with a peak latently of 300 msec, 700 msec, and both latencies. The scalp distribution of responses revealed that the region of high potentials were widely spread over the vertex, and that latency with distance towards the occipital region. A response was not recordable from a patient with anosmia. However, more study is necessary to apply this finding to objective olfactometry because that the responses were not recorded in all normal subjects.The EUG changes during odorant stimulation were investigated using the technique of SPN (significance probability mapping). The findings allowed that alpha _1, delta and rheta waves were decreased in the occipital region and that alpha_2 wave was increased at the frontal region. These EEG changes may reflect activity of the olfactory central system in the frontal region.