The ability to learn event sequences is crucial to human behavior because it enables us to interact adaptively with our environment. The sensory environment is essential in guiding the acquisition of these sequences, so the role of the stimulus modality in sequence learning is of high relevance. The present study examined structured stimulus modality shifts in sequence learning using the serial reaction time task (SRT). Participants had to respond to numbers that were presented either in the visual or in the auditory modality. Importantly, the numbers, as well as the stimulus modality, followed a fixed pattern. We found better performance in sequenced than in random blocks, indicating sequence learning. Moreover, the performance was better when the stimulus modality remained the same than when the modality changed between successive trials (the modality shift effect, MSE). However, sequence learning facilitated performance primarily in modality repetitions, so that the MSE became progressively larger in the sequenced blocks, while it was small in the random blocks, and this pattern was particularly pronounced for the participants who showed a high recall level for the response sequence. To account for this effect, we assume that consistent modality shifts induce parsing of the sequence into chunks. Because chunk retrieval at chunk boundaries incurs RT costs, the acquired sequence knowledge is more efficiently expressed in modality repetitions (i.e., within chunks). Together, the data suggest that the formation of explicit knowledge enhances chunking in sequence learning.

中文翻译：

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刺激模态的一致变化导致序列学习中的分块

学习事件序列的能力对人类行为至关重要，因为它使我们能够自适应地与环境互动。感官环境对于引导这些序列的获取至关重要，因此刺激模式在序列学习中的作用具有高度相关性。本研究使用串行反应时间任务 (SRT) 检查了序列学习中结构化刺激模式的变化。参与者必须对以视觉或听觉方式呈现的数字做出反应。重要的是，数字以及刺激方式都遵循固定模式。我们发现有序块的性能比随机块更好，这表明序列学习。而且，刺激模式保持不变时的表现比连续试验之间模式改变时的表现更好（模式转换效应，MSE）。然而，序列学习主要在模态重复中促进表现，因此 MSE 在序列块中逐渐变大，而在随机块中变小，这种模式对于表现出高回忆水平的参与者反应尤为明显顺序。考虑到这种影响，我们假设一致的模态转换会导致将序列解析为块。因为在块边界的块检索会产生 RT 成本，所获得的序列知识在模态重复中（即在块内）更有效地表达。一起，