Department for Biological and Medical Psychology, University of Bergen, Postboks 7807, 5020, Bergen, Norway.
Sci Rep. 2022 Sep 12;12(1):15296. doi: 10.1038/s41598-022-19203-7.
Statistical learning refers to the implicit mechanism of extracting regularities in our environment. Numerous studies have investigated the neural basis of statistical learning. However, how the brain responds to violations of auditory regularities based on prior (implicit) learning requires further investigation. Here, we used functional magnetic resonance imaging (fMRI) to investigate the neural correlates of processing events that are irregular based on learned local dependencies. A stream of consecutive sound triplets was presented. Unbeknown to the subjects, triplets were either (a) standard, namely triplets ending with a high probability sound or, (b) statistical deviants, namely triplets ending with a low probability sound. Participants (n = 33) underwent a learning phase outside the scanner followed by an fMRI session. Processing of statistical deviants activated a set of regions encompassing the superior temporal gyrus bilaterally, the right deep frontal operculum including lateral orbitofrontal cortex, and the right premotor cortex. Our results demonstrate that the violation of local dependencies within a statistical learning paradigm does not only engage sensory processes, but is instead reminiscent of the activation pattern during the processing of local syntactic structures in music and language, reflecting the online adaptations required for predictive coding in the context of statistical learning.
统计学习是指从环境中提取规律的内在机制。许多研究都调查了统计学习的神经基础。然而，基于先前（内隐）学习，大脑如何对听觉规律的违反做出反应仍需要进一步研究。在这里，我们使用功能磁共振成像（fMRI）来研究基于学习的局部依赖性处理不规则事件的神经相关性。连续呈现一连串的声音三元组。受试者并不知道，三元组要么是（a）标准的，即结尾是高概率声音的三元组，要么是（b）统计偏差，即结尾是低概率声音的三元组。参与者（n=33）在扫描仪外进行学习阶段，然后进行 fMRI 扫描。统计偏差的处理激活了一组包括双侧颞上回、右侧深额帽状回（包括外侧眶额皮层）和右侧运动前皮层的区域。我们的结果表明，在统计学习范式中违反局部依赖性不仅涉及感觉过程，而且类似于在音乐和语言中处理局部句法结构时的激活模式，反映了在统计学习背景下进行预测编码所需的在线适应。
