视知觉选择中负相容效应的发生机制

The negative compatibility effect (NCE) is that response times are faster and errors occur less often when the prime is unrelated to the target or has features associated with the opposite response, in comparison to when the prime is identical or similar to the target if the time between the presentation of the prime and the presentation of the target is sufficiently long. However, the mechanisms that underlie this effect in visual selection is highly debated, there are still some key issues yet to be resolved. This project is going to investigate the mechanisms that underlie NCE observed in visual selection by the combination of three kinds of measures: response times, Lateralized Readiness Potential (LRP) and the potential components related to covert attention shift, all of these are to be measured in the paradigm of negative compatibility effect (NCE). The entire research project contains five interlinked studies. Study 1 consists of two experimental designs, which use the digital stimuli and manipulate the relationship between prime and target to investigate whether the NCE-NP(which is of responding origin) is exist and further explore the relationship between NCE-P(which is of perceptual origin) and NCE-NP. Study 2 manipulates the relevance of mask and the relationship between prime and target to clarify whether object-updating could take effect on response coding or feature level. Study 3 manipulate eccentricity of prime and add the cue before it to examine the different visuo-motor link or the different perceptual strength is the crucial factor for the Central-peripheral asymmetry. Study 4 manipulates the strength of prime activation and the ISI between mask and target in two experiments to manifest that the continuous mechanism rather than the threshold mechanism is the key factor for eliciting NCE under subliminal circumstance with the evidence of LRP. Study 5 consists of two ERPs studies, which manipulates the relationship between the prime and target to investigate whether the NCE-NP could accompany attention shift, and to further digest its processing mechanism if NCE could be really triggered by attention shift. The results of the five studies may be confirmed mutually, and ultimately reveal the mechanisms of negative compatibility effect at different processing levels. The findings of the research project will not only help to clarify the nature of the negative compatibility effect but also facilitate the in-depth understanding of the relationship among different processing levels in visual selection, and to some extent, reveal the role of unconscious on human behavior.

负相容效应是指在视觉掩蔽启动范式中当启动和目标刺激的反应倾向相同比相反时，被试的反应时更长，错误率更高。但其发生机制尚未明确，还存在一定的关键科学问题尚未解决。本项目拟采用行为实验、眼动及脑电技术相结合的方法分别从知觉、反应及注意转移阶段深入探讨该效应的发生机制。研究一采用数字刺激分离知觉和反应阶段的负相容效应探讨两者间的关系；研究二操纵启动与掩蔽的关系考察刺激特征或反应编码层面的更新对该效应的影响；研究三操纵启动的离心率和线索有效性分离腹侧和背侧通路探讨该效应的中央边缘不对称现象的成因；研究四操纵掩蔽和目标间的时间间隔分离连续抑制和抑制阈限探讨该效应赖以产生的抑制机制的连续性或离散性特征；研究五操纵目标刺激类别探讨注意转移对反应层面负相容效应的作用机制。本项目的研究不仅可以解释负相容效应本身，更能深入探讨视知觉选择在多种加工层面间的关系，并一定程度地揭示无意识系统对人类行为的影响作用。

负相容效应（negative compatibility effect, NCE）是认知心理学的热门研究领域，其发生机制一直是国内外研究者所关注的问题。本项目采用行为实验、脑电（ERPs）及脑成像技术（fMRI）相结合的方法通过五大研究分别从知觉、反应及注意转移阶段深入探讨该效应的发生机制。研究一利用行为及fMRI技术，采用独创的数字刺激考察客体更新和自我抑制能否共同影响NCE的产生以及其作用的神经机制。结果发现知觉层面客体更新和反应层面自我抑制可共同作用于NCE。当启动刺激与反应间（S-R）联结较弱时，NCE主要源自客体更新加工；而当S-R联结增强且达到了抑制阈限的要求时，客体更新和自我抑制均会对NCE的产生有所贡献，但是，其中来自自我抑制的作用占据主导地位。研究二操纵启动与掩蔽的关系考察刺激特征和反应编码层面的更新对NCE的影响；结果发现这一更新过程不仅发生在特征层面，还会发生在反应层面。这一研究采用了数字刺激巧妙地考察了特征层面和反应层面更新引发的负相容效应，这是采用传统箭头刺激解决不了的一大问题。研究三利用ERPs技术，操纵启动的线索有效性探讨NCE中央边缘不对称现象的成因；结果发现呈现在边缘启动刺激只要得到一定的注意资源，使其具备较强的知觉表征也能够引发负相容效应，提示中央边缘不对称现象是由刺激知觉表征强度不同引发的。研究四操纵掩蔽和目标间的时间间隔探讨NCE赖以产生的抑制机制的连续性或离散性特征；结果表明反应层面自我抑制引发的NCE受到连续阈下抑制机制，而非抑制阈限机制的控制。研究五操纵目标刺激类别探讨注意转移对反应层面NCE的作用机制，结果表明注意转移并不能独立引发NCE，注意转移只是伴随反应阶段的抑制过程而出现，且其加工模式与动作抑制引发NCE的加工模式类似。本项目的研究结果对深入了解视知觉选择中NCE的发生机制具有重要贡献。同时也可以更深入地揭示知觉、反应及注意转移等多种加工层面之间的关系，并在一定程度上揭示无意识系统对人类行为的影响作用。