Familiarity influences visual detection in a task that does not require explicit recognition.

The current study aims to explore one factor that likely contributes to these statistical regularities, familiarity. Are highly familiar stimuli perceived more readily? Previous work showing effects of familiarity on perception have used recognition tasks, which arguably tap into post-perceptual processes. Here we use a perceptual task that does not depend on explicit recognition; participants were asked to discriminate whether a rapidly presented image was intact or scrambled. The familiarity level of stimuli was manipulated. Results show that famous or upright orientated logos (Experiments 1 and 2) or faces (Experiment 3) were better discriminated than novel or inverted logos and faces. To further dissociate our task from recognition, we implemented a simple detection task (Experiment 4) and directly compared the intact/scrambled task to a recognition task (Experiment 5) on the same set of faces used in Experiment 3. The fame and orientation familiarity effect were still present in the simple detection task, and the duration needed on the intact/scrambled task was significantly less than the recognition task. We conclude that familiarity effect demonstrated here is not driven by explicit recognition and instead reflects a true perceptual effect.