Unfamiliar Contexts Compared to Familiar Contexts Impair Learning in Humans

Re-exposure to the context that information was learned in facilitates its memory retrieval. However, influence of changes on ability learn new is less well understood, which present work investigated two experiments with healthy participants (n = 40 per experiment; 20 female). In experiment 1, a list word-pairs (A-B) morning, after their for immediately tested. evening, they and were tested second non-overlapping (C-D), either same or different than first (between-subjects). We found learning enhanced context, other decreased compared baseline. 2, exposed both contexts but only one them. session this familiarization abolished differences between group. These data point novelty interfering rather familiarity enhancing it. Importantly, reduction experiment, where unfamiliar sessions, suggests mechanisms beyond attention processes are bound by context. Rather, old impairs processing possibly biasing pattern completion separation trade-offs within hippocampus.