Li Baolin, Chen Youguo, Xiao Lijuan, Liu Peiduo, Huang Xiting
Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing 400715, China.
Key Laboratory of Cognition and Personality, Ministry of Education, Faculty of Psychology, Southwest University, Chongqing 400715, China.
Neuroimage. 2017 Feb 15;147:143-151. doi: 10.1016/j.neuroimage.2016.12.015. Epub 2016 Dec 8.
Repetitive exposure to relatively long or short sensory events has been shown to shorten or lengthen the perceived duration of a subsequent event. However, the neural basis of this phenomenon, called duration adaptation, remains unclear. In this study, we used electroencephalography (EEG) to investigate whether duration adaptation could modulate the subsequent temporal encoding represented by the contingent negative variation (CNV). Participants were asked to reproduce the duration of a test stimulus after adapting duration (Experiment 1) or after anchor duration (Experiment 2). We found that both adapting duration and anchor duration affected the reproduction duration of a subsequently presented test stimulus. The simultaneously recorded event-related potentials (ERPs) revealed that test stimuli evoked clearly identifiable N1, P2 and CNV components in the fronto-central scalp. Further analyses showed that the CNV amplitude was modulated by duration adaptation: adaptation to shorter duration (200ms) increased whereas adaptation to longer duration (800ms) decreased the CNV amplitude. These findings suggest that the neural correlates of temporal encoding represented by the CNV amplitude reflect the duration aftereffect. Additionally, the duration adaptation effect observed on the P2 component also suggests an early expectancy effect on subsequent encoding processes. Finally, no effect of anchor duration was observed on the CNV amplitude, which implies that different mechanisms underlie the duration aftereffect and the anchor effect.
反复暴露于相对较长或较短的感觉事件已被证明会缩短或延长对随后事件的感知持续时间。然而，这种被称为持续时间适应的现象的神经基础仍不清楚。在本研究中，我们使用脑电图（EEG）来研究持续时间适应是否能调节由关联负变（CNV）所代表的后续时间编码。要求参与者在适应持续时间后（实验1）或锚定持续时间后（实验2）重现测试刺激的持续时间。我们发现，适应持续时间和锚定持续时间都会影响随后呈现的测试刺激的重现持续时间。同时记录的事件相关电位（ERP）显示，测试刺激在额中央头皮诱发了清晰可辨的N1、P2和CNV成分。进一步分析表明，CNV振幅受持续时间适应的调节：适应较短持续时间（200毫秒）会增加而适应较长持续时间（800毫秒）会降低CNV振幅。这些发现表明，由CNV振幅所代表的时间编码的神经关联反映了持续时间后效。此外，在P2成分上观察到的持续时间适应效应也表明对后续编码过程有早期预期效应。最后，未观察到锚定持续时间对CNV振幅有影响，这意味着持续时间后效和锚定效应有不同的机制。
