Detailed and gist-like visual memories are forgotten at similar rates over the course of a week

A number of recent studies have highlighted the exceptional capacity and fidelity of visual long-term memory. For instance, Brady, Konkle, Alvarez, and Oliva (Proceedings of the National Academy of Sciences, 105, 14325-14329, 2008) presented participants with thousands of images for nearly 6 h and then tested their memory in a two-alternative forced choice (2AFC) task. Participants were 87% accurate, even when the foil was extremely similar to the target (e.g., when the same object was presented in a different state). In the present investigation, we extended these findings by including a one-week delay condition and by testing memory in a yes-no as well as a 2AFC task. We replicated the exceptional memory results at a short delay. However, following a week delay, recognition accuracy was greatly reduced in both tasks, with comparable reductions in performance when the foils were both similar and dissimilar. These findings suggest that detailed and gist-like visual memories decay at similar rates, which highlights important limitations of visual long-term memory.