[Effects of contextual variation during encoding on decontextualization of episodic memory].

Two experiments examined whether or not contextual variation during encoding of a list enhances decontextualization of episodic memory of the list. A total of 86 undergraduates incidentally encoded a list of 24 nouns twice under the same (same-context repetition condition) or different (different-context repetition condition) contexts with a one-week inter-encoding interval. One week after the second encoding of the list, the undergraduates were asked to free recall the list under the third neutral context. Context was manipulated by the combination of three contextual elements: physical features of environment, types of encoding tasks, and social factors. Experiment 1 revealed superiority of same-to different-context repetition condition, whereas the preceding studies manipulating only environmental features found superiority of different-to same-context repetition condition. Experiment 2, in which participants were explicitly instructed that the list used in the first and the second encoding sessions were identical, replicated the findings of Experiment 1. The present findings suggest that contextual variation between episodes does not enhance decontextualization of episodic memory.