人类自然整合来自嗅觉和鼻内三叉神经系统的信号。这两个系统之间已经证明了紧密的相互作用,然而,介导嗅觉-三叉神经(OT)整合的神经回路仍然知之甚少。使用功能磁共振成像(fMRI),结合心理物理学,这项研究调查了OT整合的神经机制。15名嗅觉功能正常的参与者通过空气抽吸刺激执行了定位任务,苯乙醇(PEA;玫瑰味),或其组合,同时被扫描。将PEA定位到任一鼻孔的能力是偶然的。然而,它的存在显著提高了弱,但不坚强,空气抽吸,当两种刺激同时传递到同一鼻孔时,但当不同的鼻孔受到两种刺激时就不会了。这种定位精度的提高,举例说明了多感官整合中的空间重合和逆有效性原则,与初级嗅觉(POC)中的多感觉综合活动有关,眶额(OFC),上颞叶(STC),下顶骨(IPC)和扣带回皮质,在小脑。这些区域的多感官增强与行为多感官增强相关,这些地区之间的连通性也在增加。我们将这些发现解释为表明POC是介导嗅觉和三叉神经系统之间整合的分布式大脑网络的一部分。练习点:嗅觉-三叉神经(OT)整合的心理物理和神经影像学研究。行为,皮质活动,和网络连接显示OT集成。OT集成遵循逆有效性和空间重合原则。OT整合的行为和神经测量是相关的。
Humans naturally integrate signals from the olfactory and intranasal trigeminal systems. A tight interplay has been demonstrated between these two systems, and yet the neural circuitry mediating olfactory-trigeminal (OT) integration remains poorly understood. Using functional magnetic resonance imaging (fMRI), combined with psychophysics, this study investigated the neural mechanisms underlying OT integration. Fifteen participants with normal olfactory function performed a localization task with air-puff stimuli, phenylethyl alcohol (PEA; rose odor), or a combination thereof while being scanned. The ability to localize PEA to either nostril was at chance. Yet, its presence significantly improved the localization accuracy of weak, but not strong, air-puffs, when both stimuli were delivered concurrently to the same nostril, but not when different nostrils received the two stimuli. This enhancement in localization accuracy, exemplifying the principles of spatial coincidence and inverse effectiveness in multisensory integration, was associated with multisensory integrative activity in the primary olfactory (POC), orbitofrontal (OFC), superior temporal (STC), inferior parietal (IPC) and cingulate cortices, and in the cerebellum. Multisensory enhancement in most of these regions correlated with behavioral multisensory enhancement, as did increases in connectivity between some of these regions. We interpret these findings as indicating that the POC is part of a distributed brain network mediating integration between the olfactory and trigeminal systems. PRACTITIONER POINTS: Psychophysical and neuroimaging study of olfactory-trigeminal (OT) integration. Behavior, cortical activity, and network connectivity show OT integration. OT integration obeys principles of inverse effectiveness and spatial coincidence. Behavioral and neural measures of OT integration are correlated.