Department of Psychological Sciences, Institute of Psychology, Health, and Society, University of Liverpool, Eleanor Rathbone Building, Bedford Street South, Liverpool, UK.
Unilever Research and Development, Quarry Rd E, Wirral, UK.
Chem Senses. 2020 Dec 5;45(9):845-854. doi: 10.1093/chemse/bjaa065.
Congruent visual cues augment sensitivity to brief olfactory presentations and habituation of odor perception is modulated by central-cognitive processing including context. However, it is not known whether habituation to odors could interact with cross-modal congruent stimuli. The present research investigated the effect of visual congruence on odor detection sensitivity during continuous odor exposures. We utilized a multimethod approach, including subjective behavioral responses and reaction times (RTs; study 1) and electroencephalography (EEG, study 2). Study 1: 25 participants received 2-min presentations of moderate-intensity floral odor delivered via olfactometer with congruent (flower) and incongruent (object) image presentations. Participants indicated odor perception after each image. Detection sensitivity and RTs were analyzed in epochs covering the period of habituation. Study 2: 25 new participants underwent EEG recordings during 145-s blocks of odor presentations with congruent or incongruent images. Participants passively observed images and intermittently rated the perceived intensity of odor. Event-related potential analysis was utilized to evaluate brain processing related to odor-visual pairs across the period of habituation. Odor detection sensitivity and RTs were improved by congruent visual cues. Results highlighted a diminishing influence of visual congruence on odor detection sensitivity as habituation occurred. Event-related potential analysis revealed an effect of congruency on electrophysiological processing in the N400 component. This was only evident in early periods of odor exposure when perception was strong. For the first time, this demonstrates the modulation of central processing of odor-visual pairs by habituation. Frontal negativity (N400) responses encode the aspects of cross-modal congruence for odor-vision cross-modal tasks.
一致的视觉提示增强了对短暂嗅觉呈现的敏感性，而嗅觉感知的习惯化受到包括上下文在内的中枢认知处理的调节。然而，目前尚不清楚嗅觉习惯化是否会与跨模态一致的刺激相互作用。本研究调查了在连续嗅觉暴露期间视觉一致性对嗅觉检测敏感性的影响。我们采用了多方法的方法，包括主观行为反应和反应时间（RT；研究 1）和脑电图（EEG，研究 2）。研究 1：25 名参与者通过嗅觉计接受 2 分钟中等强度花香的呈现，同时呈现一致（花）和不一致（物体）的图像。参与者在每次呈现图像后表示嗅觉感知。在习惯化期间的时期内分析检测敏感性和 RTs。研究 2：25 名新参与者在 145 秒的气味呈现期间进行 EEG 记录，同时呈现一致或不一致的图像。参与者被动观察图像并间歇性地对感知到的气味强度进行评分。利用事件相关电位分析评估了习惯化过程中与气味-视觉对相关的大脑处理。一致的视觉提示提高了嗅觉检测的敏感性和 RTs。结果突出了随着习惯化的发生，视觉一致性对嗅觉检测敏感性的影响逐渐减弱。事件相关电位分析显示，在 N400 成分中，一致性对电生理处理有影响。这仅在感知强烈的早期气味暴露期间才明显。这首次证明了习惯化对气味-视觉对的中枢处理的调制。额部负性（N400）反应为气味-视觉跨模态任务的跨模态一致性的各个方面编码。
