Abstract
Our experience is highly repetitive, with similar events appearing repeatedly over time in different contexts. While it is crucial to form and maintain separate visual long-term memories of similar experiences, the memory system should also be able to learn structures common to those experiences. How does the memory system balance forming separate memories vs. extracting commonalities across overlapping experiences? Here we tested whether overlap of encoding contexts facilitates integration of similar events, leading to greater structural knowledge of related experiences. We tested this idea in a series of behavioral studies consisting of encoding and memory test phases. In the encoding phase, four similar exemplars from each of different scene categories were presented (e.g., factory1, …, factory4). Crucially, for half of the categories, the exemplars were presented within the same encoding run (Within-context condition); for the other half of the categories, the exemplars were encoded across different runs (Across-context condition). In the subsequent memory test administered a day later, participants performed an old/new recognition test for a subset of the previously presented exemplars (old items) with novel exemplars from the same categories serving as lures. We specifically hypothesized that the encoding context overlap in the within-context condition would promote categorical knowledge compared to the across-context condition. This hypothesis was strongly supported by behavioral results. Namely, the within-context condition was associated with increased false memory for lures as well as increased true memory for the old items, suggesting a general strengthening of category-level information. However, this pattern was eliminated in a separate study when the memory test was administered immediately after the encoding phase, suggesting that encoding context overlap between similar experiences, rather than initial encoding strength, affects learning of categorical knowledge. These findings shed light on how the memory system acquires structural knowledge across overlapping visual experiences.
Acknowledgement: 18-BR-01-07 & IBS-R001-D1-2018-b01