Institute of Medical Psychology and Systems Neuroscience, University of Münster, Von-Esmarch-Str. 52, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany.
Institute of Medical Psychology and Systems Neuroscience, University of Münster, Von-Esmarch-Str. 52, 48149 Münster, Germany; Otto Creutzfeldt Center for Cognitive and Behavioral Neuroscience, University of Münster, 48149 Münster, Germany.
Neuroimage. 2021 Mar;228:117712. doi: 10.1016/j.neuroimage.2020.117712. Epub 2020 Dec 31.
In recent years, several ERP components have been identified as potential neural correlates of consciousness (NCC), including early negativities and late positivities. Based on experiments in the visual modality, it has recently been shown that awareness is often confounded with reporting it, possibly overestimating the NCC. It is unknown whether similar constraints also exist in the auditory modality. In order to address this gap, we presented spoken words in a sustained inattentional deafness paradigm. Electrophysiological responses were obtained in three physically identical experimental conditions that differed only with respect to the participants' instructions. Participants were either left uninformed or informed about the presence of spoken words while confronted with an auditory distractor task (U/I condition), informed about the words while exposed to the same task as before (I condition), or requested to respond to the now task-relevant speech stimuli (TR condition). After completion of the U/I condition, only informed participants reported awareness of the words. In ERPs, awareness of words in the U/I and I condition was accompanied by an anterior auditory awareness negativity (AAN). Only when stimuli were task-relevant, i.e., during the TR condition, late positivities emerged. Taken together, these results indicate that early negativities but not late positivities index awareness across sensory modalities. Thus, they provide evidence for a recurrent processing framework, which highlights the importance of early sensory processing in conscious perception.
近年来,已有数种 ERP 成分被确定为意识的潜在神经关联物(NCC),包括早期负向波和晚期正向波。基于视觉模态的实验,最近表明意识通常与报告混淆,可能高估了 NCC。尚不清楚在听觉模态中是否也存在类似的限制。为了解决这一差距,我们在持续的不注意失聪范式中呈现了口语单词。在三个物理上完全相同的实验条件下获得了电生理反应,这些条件仅在参与者的指令上有所不同。参与者要么没有得到通知,要么在面对听觉干扰任务时被告知有口语单词(U/I 条件),要么在暴露于与之前相同的任务时被告知有口语单词(I 条件),要么被要求对现在与任务相关的语音刺激做出反应(TR 条件)。在 U/I 条件完成后,只有被告知的参与者报告了对单词的意识。在 ERP 中,U/I 和 I 条件下对单词的意识伴随着前听觉意识负向波(AAN)。只有当刺激与任务相关时,即在 TR 条件下,才会出现晚期正向波。综上所述,这些结果表明早期负向波而非晚期正向波跨感觉模态指示意识。因此,它们为重复处理框架提供了证据,该框架强调了早期感觉处理在意识感知中的重要性。