Institute of Psychology, University of Leipzig, Leipzig, Germany.
Department of Psychology, University of Potsdam, Potsdam, Germany.
Eur J Neurosci. 2021 Apr;53(8):2740-2754. doi: 10.1111/ejn.15123. Epub 2021 Feb 12.
The auditory system is highly sensitive to recurring patterns in the acoustic input - even in otherwise unstructured material, such as white noise or random tonal sequences. Electroencephalography (EEG) research revealed a characteristic negative potential to periodically recurring auditory patterns - a response, which has been interpreted as memory trace-related and specific, rather than as a sign of periodicity-driven entrainment. Here, we aim to disentangle these two possible contributions by investigating the influence of a periodic sound sequence's inherent temporal regularity on event-related potentials. Participants were presented continuous sequences of short tones of random pitch, with some sequences containing a recurring pattern, and asked to indicate whether they heard a repetition. Patterns were either spaced equally across the random sequence (isochronous condition) or with a temporal jitter (jittered condition), which enabled us to differentiate between event-related potentials (and thus processing operations associated with a memory trace for a repeated pattern) and the periodic nature of the repetitions. A negative recurrence-related component could be observed independently of temporal regularity, was pattern-specific, and modulated by across trial repetition of the pattern. Critically, isochronous pattern repetition induced an additional early periodicity-related positive component, which started to build up already before the pattern onset and which was elicited undampedly even when the repeated pattern was occasionally not presented. This positive component likely reflects a sensory driven entrainment process that could be the foundation of a behavioural benefit in detecting temporally regular repetitions.
听觉系统对声音输入中的重复模式非常敏感——即使在其他非结构化的材料中，如白噪声或随机音调序列。脑电图 (EEG) 研究揭示了周期性听觉模式的特征负电位——这种反应被解释为与记忆痕迹相关且特定的，而不是周期性驱动的顺应的迹象。在这里，我们旨在通过研究周期性声音序列的固有时间规律性对事件相关电位的影响来区分这两种可能的贡献。参与者被呈现连续的短随机音调序列，其中一些序列包含重复模式，并被要求指示是否听到重复。模式要么在随机序列中均匀间隔（等时条件），要么具有时间抖动（抖动条件），这使我们能够区分事件相关电位（以及因此与重复模式的记忆痕迹相关的处理操作）和重复的周期性性质。可以观察到与时间规律性无关的负重复相关成分，该成分具有模式特异性，并受模式跨试验重复的调制。关键是，等时重复模式会引发额外的早期周期性相关正成分，该成分在模式开始之前就已经开始建立，即使重复模式偶尔不出现，也能不受抑制地引发。这个正成分可能反映了一种感官驱动的顺应过程，它可能是检测时间规律重复的行为优势的基础。
