Attention and Structure in Sequence Learning

In this study we investigated the role of attention, sequence structure, and effector specificity in learning a structured sequence of actions. Experiment 1 demonstrated that simple structured sequences can be learned in the presence of attentional distraction. The learning is unaffected by variation in distractor task difficulty, and subjects appear unaware of the structure. The structured sequence knowledge transfers from finger production to arm production (Experiment 2), suggesting that sequence specification resides in an effector-independent system. Experiments 3 and 4 demonstrated that only structures with at least some unique associations (e.g., any association in Structure 15243... or 4 to 3 in Structure 143132...) can be learned under attentional distraction. Structures with all items repeated in different orders in different parts of the structure (e.g., Sequence 132312...) require attention for learning. Such structures may require hierarchic representation, the construction of which takes attention.