Episodic and semantic memory processes in the boundary extension effect: An investigation using the remember/know paradigm

Background: Boundary extension (BE) is a phenomenon where participants report from memory that they have experienced more information of a scene than was initially presented. The goal of the current study was to investigate whether BE is fully based on episodic memory or also involves semantic scheme knowledge. Methods: The study incorporated the remember/know paradigm into a BE task. Scenes were first learned incidentally, with participants later indicating whether they remembered or knew that they had seen the scene before. Next, they had to rate 3 views - zoomed in, zoomed out or unchanged - of the original picture on similarity in closeness in order to measure BE. Results: The results showed a systematic BE pattern, but no difference in the amount of BE for episodic (‘remember’) and semantic (‘know’) memory. Additionally, the remember/know paradigm used in this study showed good sensitivity for both the remember and know responses. Discussion: The results suggest that BE might not critically depend on the contextual information provided by episodic memory, but rather depends on schematic knowledge shared by episodic and semantic memory. Schematic knowledge might be involved in BE by providing an expectation of what likely lies beyond the boundaries of the scene based on semantic guidance. GEL classification: 2343 learning & memory