Hucke Christine Ida, Heinen Rebekka Margret, Pacharra Marlene, Wascher Edmund, van Thriel Christoph
Department of Toxicology, Neurotoxicology and Chemosensation, Leibniz Research Centre for Working Environment and Human Factors at the TU Dortmund, Dortmund, Germany.
Department Neuropsychology, Institute of Cognitive Neuroscience, Ruhr-University Bochum, Bochum, Germany.
Front Neurosci. 2021 Jan 13;14:620723. doi: 10.3389/fnins.2020.620723. eCollection 2020.
The neuronal cascade related to the perception of either purely olfactory or trigeminal airborne chemicals has been investigated using electroencephalography (EEG) microstate analyses and source localization. However, most airborne chemicals are bimodal in nature, encompassing both properties. Moreover, there is an ongoing debate regarding whether there is one dominant nostril, and this could be investigated using these multichannel EEG methods. In this study, 18 right-handed, healthy participants (13 females) were monorhinally stimulated using an olfactometer with the bimodal component acetic acid during continuous EEG recording. Participants indicated the side of stimulation, the confidence in their decision, and rated the strength of the evoked perception. EEG microstate clustering determined four distinct maps and successive backfitting procedures, and source estimations revealed a network that evolved from visual-spatial processing areas to brain areas related to basic olfactory and trigeminal sensations (e.g., thalamus, cingulate cortex, insula, parahippocampal, and pre-/post-central gyri) and resulted in activation of areas involved in multisensory integration (e.g., frontal-temporal areas). Right-nostril stimulation was associated with faster microstate transition and longer involvement of the superior temporal gyrus, which was previously linked to chemical localization and provides evidence for a potential nostril dominance. The results describe for the first time the processing cascade of bimodal odor perception using microstate analyses and demonstrate its feasibility to further investigate potential nostril dominance.
利用脑电图（EEG）微状态分析和源定位技术，对与纯嗅觉或三叉神经空气传播化学物质感知相关的神经元级联反应进行了研究。然而，大多数空气传播化学物质本质上是双峰的，兼具这两种特性。此外，关于是否存在一个占主导地位的鼻孔，目前仍存在争议，而这可以通过这些多通道EEG方法进行研究。在本研究中，18名右利手健康参与者（13名女性）在连续EEG记录期间，使用带有双峰成分醋酸的嗅觉计进行单鼻孔刺激。参与者指出刺激的一侧、对其决定的信心，并对诱发感知的强度进行评分。EEG微状态聚类确定了四个不同的图谱和连续的反向拟合程序，源估计揭示了一个从视觉空间处理区域演变为与基本嗅觉和三叉神经感觉相关的脑区（如丘脑、扣带回皮质、岛叶、海马旁回以及中央前/后回）的网络，并导致涉及多感官整合的区域（如额颞区域）激活。右鼻孔刺激与更快的微状态转换以及颞上回更长时间的参与相关，颞上回先前与化学定位有关，这为潜在的鼻孔优势提供了证据。研究结果首次使用微状态分析描述了双峰气味感知的处理级联反应，并证明了其进一步研究潜在鼻孔优势的可行性。
