Frasnelli Johannes, Wohlgemuth Christiane, Hummel Thomas
Smell and Taste Clinic, Department of Otorhinolaryngology, University of Dresden Medical School, Fetscherstr. 74, 01307 Dresden, Germany.
Int J Psychophysiol. 2006 Oct;62(1):24-9. doi: 10.1016/j.ijpsycho.2005.11.006. Epub 2006 Jan 18.
Although different parameters are known to alter the shape of olfactory event related potentials (ERP), ERP parameters are generally thought to be independent from stimulus duration. Evidence from recent studies investigating trigeminal ERP indicates that this may not be true. Aim of the present study was to investigate the relationship of stimulus duration and ERP. A total of 20 young healthy subjects participated. Subjects were investigated on 5 occasions on 5 different days. ERP were recorded to olfactory stimuli of two different concentrations and 3 different durations (100 ms, 200 ms, 300 ms). In two sessions olfactory ERP to PEA were recorded, in another two sessions H2S was applied. During the same sessions, intensity ratings were recorded. In the fifth session, subjects were asked to rate the duration of H2S stimuli and PEA stimuli. Whereas at weak stimulus concentrations no effect of stimulus duration could be observed, there was a clear effect of "duration" in ERP amplitudes following stimuli with higher concentrations: the longer the stimulus duration the larger the ERP amplitudes. No effect was found on ERP latencies. With regard to intensity ratings, strong stimuli and longer lasting stimuli lead to higher ratings. Similarly, ratings of stimulus duration were dependent from stimulus concentration and stimulus duration. Results of the present study showed that similar to trigeminal ERP, information about stimulus duration is encoded in olfactory ERP, mainly in amplitudes.
虽然已知不同参数会改变嗅觉事件相关电位（ERP）的波形，但ERP参数通常被认为与刺激持续时间无关。近期对三叉神经ERP的研究证据表明情况可能并非如此。本研究的目的是探究刺激持续时间与ERP之间的关系。共有20名年轻健康受试者参与。受试者在5个不同日期接受了5次测试。记录了对两种不同浓度和3种不同持续时间（100毫秒、200毫秒、300毫秒）的嗅觉刺激的ERP。在两个测试环节中记录了对苯乙胺（PEA）的嗅觉ERP，在另外两个测试环节中施加了硫化氢（H2S）。在同一测试环节中，记录了强度评分。在第五个测试环节中，要求受试者对H2S刺激和PEA刺激的持续时间进行评分。在弱刺激浓度下未观察到刺激持续时间的影响，但在较高浓度刺激后的ERP波幅中存在明显的“持续时间”效应：刺激持续时间越长，ERP波幅越大。在ERP潜伏期方面未发现影响。关于强度评分，强刺激和持续时间更长的刺激会导致更高的评分。同样，对刺激持续时间的评分取决于刺激浓度和刺激持续时间。本研究结果表明，与三叉神经ERP类似，关于刺激持续时间的信息在嗅觉ERP中被编码，主要体现在波幅上。
