Although statistical regularities in the environment often go explicitly unnoticed, traces of implicit learning are evident in our neural activity. Recent perspectives have offered evidence that both pre-stimulus oscillations and peri-stimulus event-related potentials are reliable biomarkers of implicit expectations arising from statistical learning. What remains ambiguous, however, is the origination and development of these implicit expectations. To address this lack of knowledge and determine the temporal constraints of expectation formation, pre-stimulus increases in alpha/beta power were investigated alongside a reduction in the N170 and a suppression in peri-/post-stimulus gamma power. Electroencephalography was acquired from naive participants who engaged in a gender classification task. Participants were uninformed, that eight face images were sorted into four reoccurring pairs which were pseudorandomly hidden amongst randomly occurring face images. We found a reduced N170 for statistically expected images at left parietal and temporo-parietal electrodes. Furthermore, enhanced gamma power following the presentation of random images emphasized the bottom-up processing of these arbitrary occurrences. In contrast, enhanced alpha/beta power was evident pre-stimulus for expected relative to random faces. A particularly interesting finding was the early onset of alpha/beta power enhancement which peaked immediately after the depiction of the predictive face. Hence, our findings propose an approximate timeframe throughout which consistent traces of enhanced alpha/beta power illustrate the early prioritisation of top-down processes to facilitate the development of implicitly cued face-related expectations.

中文翻译：

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早期的 alpha/beta 振荡反映了大脑中与面部相关的期望的形成。

尽管环境中的统计规律经常被明显地忽视，但在我们的神经活动中，内隐学习的痕迹很明显。最近的观点提供的证据表明，刺激前振荡和刺激周围事件相关电位都是统计学习产生的内隐期望的可靠生物标志物。然而，仍然模棱两可的是这些隐含期望的起源和发展。为了解决这种知识的缺乏并确定期望形成的时间限制，研究了 alpha/beta 功率的刺激前增加以及 N170 的减少和刺激前/刺激后伽马功率的抑制。脑电图是从参与性别分类任务的天真的参与者那里获得的。参与者不知情，八张人脸图像被分为四个重复出现的对，这些对伪随机地隐藏在随机出现的人脸图像中。我们发现左顶叶和颞顶叶电极的统计预期图像的 N170 降低。此外，随机图像呈现后增强的伽马功率强调了对这些任意事件的自下而上的处理。相比之下，相对于随机面孔，增强的 alpha/beta 功率是预期的明显预刺激。一个特别有趣的发现是 alpha/beta 能量增强的早期开始，在描述预测面部后立即达到峰值。因此，