What makes a picture memorable?

‘Mental sports’ have become a new trend in self-improvement, with video games designed to improve mental fitness. At the World Memory Championships, athletes compete to recall massive amounts of information; contestants must memorize and recall sequences of abstract images and the names of people whose faces are shown in photographs. While these tasks might seem challenging, our research suggests that images that possess certain properties are memorable. Our findings can explain why we have all had some images stuck in our minds, but ignored or quickly forgotten others. Although image memorability seems subjective and hard to quantify, our recent work1–5 shows that it is not an inexplicable phenomenon. We found that visual memorability is largely intrinsic to the image and reproducible across a diverse population. This means that despite varied experiences, individuals tend to remember and forget the same images. Using experimental data detailing the types of images people remember or quickly forget, we developed an algorithm that automatically predicts whether an image will be memorable. To determine the intrinsic features that make an image memorable, we first asked 665 individuals to participate in a computer memory game. During each level of the game, for up to 30 levels, participants viewed a stream of images and then pressed the space bar whenever they saw one of those images repeated in a subsequent sequence. In total, the image database contained 2222 repeated images and 8220 unrepeated images that included faces, interior-design photos, nature scenes, streetscapes, and others. We found that photographs with people or central objects were memorable, whereas landscapes—that one might expect to be memorable—were among the most forgettable (see Figure 1).1 Next, we assigned a ‘memorability score’ to each image, which was defined as the percent of correct detections by participants in the study. On average, 78 participants scored each Figure 1. A sample of the photos used to develop an algorithm that predicts image memorability.1 The photos are scaled according to their experimentally measured memorability, with the most memorable photos appearing larger and in the center.