Properties of visual episodic memory following repeated encounters with objects

A person sees an object once, and then seconds, minutes, hours, days, or weeks later, she sees it again. How is the person's visual memory for that object changed, improved, or degraded by the second encounter, compared to a situation in which she will have only seen the object once? The answer is unknown, a glaring lacuna in the current understanding of visual episodic memory. The overwhelming majority of research considers recognition following a single exposure to a set of objects, whereas objects reoccur regularly in lived experience. We therefore sought to address some of the more basic and salient questions that are unanswered with respect to how repetition affects visual episodic memory. In particular, we investigated how spacing between repeated encounters affects memory, as well as variable input quality across encounters and changes in viewed orientation. Memory was better when the spacing between encounters was larger, and when a first encounter with an object supplied high quality input (compared to low quality input first, followed later by higher quality input). These experiments lay a foundation for further understanding how memory changes, improves, and degrades over the course of experience.