认知与发展心理学研究室知识库

我们对于感知觉刺激的行为反应在很大程度上取决于刺激本身的吸引性或排斥性，即效价。虽然一般认为效价在边缘系统内得到加工，但是目前对于效价在人类嗅觉通道的作用尚存争议。同时，周遭的世界每时每刻都在向我们的各个感觉通道提供丰富的信息，而效价正是一个具有多感觉通道普适性的属性。跨通道信息的效价标签如何得到编码、相互之间是否存在交互效应，这些基本问题对于理解感知觉信息加工背后的机制有不可忽视的意义。本论文针对效价研究领域中的不足之处，提出2项研究，进一步揭示了探讨了基于效价信息的嗅觉刺激加工过程、跨感觉通道信息交互过程中的认知加工特性和内在神经机制。具体内容如下：
（1）研究一以多种具有好恶效价的嗅觉刺激作为研究对象，采用“气味混合”与“嗅觉适应”的实验范式，探究情绪效价在嗅觉信息编码过程中的作用及特点；结果表明，愉悦度在嗅觉感受层面作为基本线性维度是缺乏合理性的。
（2）研究二将不同效价的嗅觉刺激与“眼间抑制”、“内隐联结配对”的实验范式相结合，采用行为实验、核磁共振成像等方式，检验针对跨感觉通道效价标签的加工机制以及背后的神经基础；研究结果共同揭示了由杏仁核、颞上沟所介导的皮层下神经通路，对跨感觉通道的效价信息在无意识过程中进行加工的机制。

Our behavioral response to a sensory stimulus depends in large on its intrinsic attractiveness or aversiveness, viz. valence. It is generally accepted that valence is encoded in limbic system, yet not much is known regarding the valence encoding in human olfaction. Although valence is applied to multimodal stimuli, whether cross-modal integration can be based on valence, and in what form does the human brain encode the perceptual valence from multiple channels remain unknown. Here two studies are proposed in an effort to reveal the human valence processing and its interplays with the limbic system. Specifically,
(a) Study I employs the valence assessment of hedonically binary odor mixture and adaption paradigm of olfactory valence, to argue against the validity of pleasantness as the primary axis in processing a odor object;
(b) Study II introduces olfactory cues to the interocular suppression paradigm and implicit pairing procedure in both the behavioral and fMRI experiments, to reveal the interlinked encodings of facial affect and odor hedonic tone, particularly below awareness.