Department of Psychology, University of Amsterdam, Amsterdam, Netherlands; Amsterdam Brain and Cognition, University of Amsterdam, Amsterdam, Netherlands.
Department of Applied and Experimental Psychology, Vrije Universiteit Amsterdam, Netherlands; Institute for Brain and Behavior, Vrije Universiteit Amsterdam, Netherlands.
Neuroimage. 2021 Apr 15;230:117789. doi: 10.1016/j.neuroimage.2021.117789. Epub 2021 Jan 23.
Our senses are continuously bombarded with more information than our brain can process up to the level of awareness. The present study aimed to enhance understanding on how attentional selection shapes conscious access under conditions of rapidly changing input. Using an attention task, EEG, and multivariate decoding of individual target- and distractor-defining features, we specifically examined dynamic changes in the representation of targets and distractors as a function of conscious access and the task-relevance (target or distractor) of the preceding item in the RSVP stream. At the behavioral level, replicating previous work and suggestive of a flexible gating mechanism, we found a significant impairment in conscious access to targets (T2) that were preceded by a target (T1) followed by one or two distractors (i.e., the attentional blink), but striking facilitation of conscious access to targets shown directly after another target (i.e., lag-1 sparing and blink reversal). At the neural level, conscious access to T2 was associated with enhanced early- and late-stage T1 representations and enhanced late-stage D1 representations, and interestingly, could be predicted based on the pattern of EEG activation well before T1 was presented. Yet, across task conditions, we did not find convincing evidence for the notion that conscious access is affected by rapid top-down selection-related modulations of the strength of early sensory representations induced by the preceding visual event. These results cannot easily be explained by existing accounts of how attentional selection shapes conscious access under rapidly changing input conditions, and have important implications for theories of the attentional blink and consciousness more generally.
我们的感官不断受到大脑无法处理到意识水平的信息轰炸。本研究旨在更深入地了解注意力选择如何在快速变化的输入条件下塑造意识获取。通过使用注意任务、EEG 和个体目标和干扰定义特征的多元解码,我们特别研究了作为意识获取和任务相关性(目标或干扰)的函数,目标和干扰的表示在 RSVP 流中如何动态变化。在行为层面上,我们复制了之前的工作,并表明存在灵活的门控机制,发现当目标(T1)后面紧接着一个或两个干扰物(即注意瞬脱)时,目标(T2)的意识获取会受到显著损害,但当目标(T2)直接紧随另一个目标时,意识获取会显著增强(即滞后 1 保护和瞬脱反转)。在神经层面上,T2 的意识获取与 T1 的早期和晚期表示增强以及 D1 的晚期表示增强有关,有趣的是,在 T1 呈现之前,就可以根据 EEG 激活模式很好地预测 T2 的意识获取。然而,在不同的任务条件下,我们没有找到令人信服的证据表明,意识获取受到由先前视觉事件引起的早期感觉表示的快速自上而下选择相关调制强度的影响。这些结果不能简单地用现有的注意力选择如何在快速变化的输入条件下塑造意识获取的理论来解释,并且对注意瞬脱和意识的理论具有重要意义。