Flohr Elena L R, Boesveldt Sanne, Haehner Antje, Iannilli Emilia, Sinding Charlotte, Hummel Thomas
Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany; Department of Psychology (Biological Psychology, Clinical Psychology, and Psychotherapy), University of Würzburg, Germany.
Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Germany; Division of Human Nutrition, Wageningen University, Wageningen, the Netherlands; Department of Neurology, VU University Medical Center, Amsterdam, the Netherlands.
Int J Psychophysiol. 2015 Mar;95(3):388-94. doi: 10.1016/j.ijpsycho.2015.01.014. Epub 2015 Feb 16.
Habituation of responses to chemosensory signals has been explored in many ways. Strong habituation and adaptation processes can be observed at the various levels of processing. For example, with repeated exposure, amplitudes of chemosensory event-related potentials (ERP) decrease over time. However, long-term habituation has not been investigated so far and investigations of differences in habituation between trigeminal and olfactory ERPs are very rare. The present study investigated habituation over a period of approximately 80 min for two olfactory and one trigeminal stimulus, respectively. Habituation was examined analyzing the N1 and P2 amplitudes and latencies of chemosensory ERPs and intensity ratings. It was shown that amplitudes of both components - and intensity ratings - decreased from the first to the last block. Concerning ERP latencies no effects of habituation were seen. Amplitudes of trigeminal ERPs diminished faster than amplitudes of olfactory ERPs, indicating that the habituation of trigeminal ERPs is stronger than habituation of olfactory ERPs. Amplitudes of trigeminal ERPs were generally higher than amplitudes of olfactory ERPs, as it has been shown in various studies before. The results reflect relatively selective central changes in response to chemosensory stimuli over time.
对化学感应信号反应的习惯化已通过多种方式进行了探索。在处理的各个层面都能观察到强烈的习惯化和适应过程。例如，随着反复接触，化学感应事件相关电位（ERP）的振幅会随时间降低。然而，到目前为止尚未对长期习惯化进行研究，并且对三叉神经ERP和嗅觉ERP之间习惯化差异的研究非常罕见。本研究分别对两种嗅觉刺激和一种三叉神经刺激在约80分钟的时间段内的习惯化情况进行了研究。通过分析化学感应ERP的N1和P2振幅及潜伏期以及强度评级来检测习惯化。结果表明，从第一个时间段到最后一个时间段，这两个成分的振幅以及强度评级都降低了。关于ERP潜伏期，未观察到习惯化效应。三叉神经ERP的振幅比嗅觉ERP的振幅下降得更快，表明三叉神经ERP的习惯化比嗅觉ERP的习惯化更强。如之前在各种研究中所表明的，三叉神经ERP的振幅通常高于嗅觉ERP的振幅。这些结果反映了随着时间推移，对化学感应刺激的反应相对具有选择性的中枢变化。
