Institute of Psychology, CAS Key Laboratory of Behavioral Science, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Beijing 100101, China.
Department of Psychology, University of Chinese Academy of Sciences, Beijing 100049, China.
Cereb Cortex. 2018 May 1;28(5):1718-1728. doi: 10.1093/cercor/bhx068.
Our perception of the world builds upon dynamic inputs from multiple senses with different temporal resolutions, and is threaded with the passing of subjective time. How time is extracted from multisensory inputs is scantly known. Utilizing psychophysical testing and electroencephalography, we show in healthy human adults that odors modulate object visibility around critical flicker-fusion frequency (CFF)-the limit at which chromatic flickers become perceived as a stable color-and effectively alter CFF in a congruency-based manner, despite that they afford no clear environmental temporal information. The behavioral gain produced by a congruent relative to an incongruent odor is accompanied by elevated neural oscillatory power around the object's flicker frequency in the right temporal region ~150-300 ms after object onset, and is not mediated by visual awareness. In parallel, odors bias the subjective duration of visual objects without affecting one's temporal sensitivity. These findings point to a neuronal network in the right temporal cortex that executes flexible temporal filtering of upstream visual inputs based on olfactory information. Moreover, they collectively indicate that the very process of sensory integration at the stage of object processing twists time perception, hence casting new insights into the neural timing of multisensory events.
我们对世界的感知是基于具有不同时间分辨率的多种感觉的动态输入，并与主观时间的流逝交织在一起。从多感觉输入中提取时间的方法知之甚少。利用心理物理学测试和脑电图，我们在健康的成年人类中表明，气味可以调节对象在临界闪烁融合频率（CFF）周围的可见性-在该频率下，颜色闪烁会被感知为稳定的颜色-并且可以有效地以基于一致性的方式改变 CFF，尽管它们没有提供明确的环境时间信息。与不一致的气味相比，一致的气味会产生行为增益，这伴随着在对象出现后约 150-300 毫秒的右颞区中对象闪烁频率周围的神经振荡功率升高，并且不受视觉意识的影响。同时，气味会影响视觉对象的主观持续时间而不影响其时间敏感性。这些发现指向右颞皮质中的神经元网络，该网络根据嗅觉信息对上游视觉输入执行灵活的时间滤波。此外，它们共同表明，在对象处理阶段进行的感觉整合过程会扭曲时间感知，从而为多感觉事件的神经计时提供新的见解。
