Center for Mathematics, Computing and Cognition, Universidade Federal do ABC (UFABC), São Bernardo do Campo, Sao Paolo, Brazil.
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands.
Eur J Neurosci. 2022 Jun;55(11-12):3324-3339. doi: 10.1111/ejn.15405. Epub 2021 Aug 9.
Being able to anticipate events before they happen facilitates stimulus processing. The anticipation of the contents of events is thought to be implemented by the elicitation of prestimulus templates in sensory cortex. In contrast, the anticipation of the timing of events is typically associated with entrainment of neural oscillations. It is so far unknown whether and in which conditions temporal expectations interact with feature-based expectations, and, consequently, whether entrainment modulates the generation of content-specific sensory templates. In this study, we investigated the role of temporal expectations in a sensory discrimination task. We presented participants with rhythmically interleaved visual and auditory streams of relevant and irrelevant stimuli while measuring neural activity using magnetoencephalography. We found no evidence that rhythmic stimulation induced prestimulus feature templates. However, we did observe clear anticipatory rhythmic preactivation of the relevant sensory cortices. This oscillatory activity peaked at behaviourally relevant, in-phase, intervals. Our results suggest that temporal expectations about stimulus features do not behave similarly to explicitly cued, nonrhythmic, expectations, yet elicit a distinct form of modality-specific preactivation.
能够在事件发生之前预测事件有助于刺激处理。据认为，对事件内容的预测是通过在感觉皮层中引出预刺激模板来实现的。相比之下，对事件时间的预测通常与神经振荡的同步有关。目前还不知道时间预期是否以及在哪些条件下与基于特征的预期相互作用，因此，同步是否调节特定于内容的感觉模板的生成。在这项研究中，我们调查了时间预期在感觉辨别任务中的作用。我们向参与者呈现了有节奏地交错的视觉和听觉流，其中包含相关和不相关的刺激，同时使用脑磁图测量神经活动。我们没有发现有节奏的刺激会诱导预刺激特征模板的证据。然而，我们确实观察到了与相关感觉皮层的清晰的、有节奏的、预激活。这种振荡活动在行为相关的、同相的间隔处达到峰值。我们的结果表明，关于刺激特征的时间预期与明确提示的非节奏预期不同，而是引发了一种独特的、模态特异性的预激活。
