颜色相关外源性特征注意与视觉意识的关系

The relationship between exogenous attention and visual consciousness

众多意识理论都强调注意在意识的产生过程中起到非常重要的作用,注意选择性地加强刺激相关的神经活动,因此注意带来的知觉增强能够对视觉意识的产生有促进作用。然而,这项观点受到了越来越多的实证证据的挑战。先前研究关注的焦点主要是内源性注意,注意是一个多面的现象,不同类型注意和意识的关系可能并不完全相同。尽管逐渐增加的证据揭示出内源性注意和意识彼此独立,是否在一定的情境下外源性注意和意识也存在相互独立的证据则需要进一步的探索。为了探明上述问题,在本研究中,物理特征相同的刺激仅在一半的试次中是可见的。除此以外,通过调整刺激线索与目标的一致性操纵注意。研究的结果显示出,与颜色相关的外源性注意相关的效应在对微弱运动速度改变方式的辨别正确率以及反应时方面表现出来,实验中并没有发现颜色相关外源性注意与视觉意识的交互作用。我们的结果因此揭示出颜色相关外源性注意在行为水平上可以独立于视觉意识。

Many theories of consciousness posit that neural amplification plays a key role for a given piece of information to reach awareness. It seems reasonable to assume that sensory amplification by attention fosters visual awareness, because attention selectively enhances neural responses to relevant targets. This view has been challenged by an increasing number of empirical evidence. In behaviour, with evidence that attention can adjust subconscious process, and at the neural level, attention and consciousness may rely on independent neural basis. However, attention is a multidimensional phenomenon, and the relationship between different types of attention and consciousness may not be identical. Previous research focuses mainly on endogenous attention. Besides, to fully understand the relationship between attention and consciousness, exogenous attention also need to be considered. In the comparative study of several studies onendogenous and exogenous attention, it is found that the relationship between consciousnessand exogenous attention is quite differerent from that of endogenous attention. Despite the increasing evidence that endogenous attention and awareness are independent of each other, it still needs to be tested whether exogenous attention is independent of awarenessin a given context. To ascertain the above problem, in this study,physically identical stimulus are visible in only half of the trials. In addition, physically identical stimulus can be classfied as attended/unattended based on the color congruency between cue and target. At thebehavioral level,the results of the study showed that the effects of color related exogenous attention is shown by the correct percentage and response time on disciminating the type of speed-change. No interaction between color related exogenous attention and visual consciousness was found in current study. Our results thus suggest that color related exogenous attention can be partly independent of visual awareness at the behavioral level. So, under certain circumstances, the exogenous attention and consciousness are independent of each other.