Fixation durations on familiar items are longer due to attenuation of exploration.

Previous studies have shown that fixations on familiar stimuli tend to be longer than on unfamiliar stimuli, theorized to be a result of retrieval of information from memory. We hypothesize that extended fixations are due to a lesser need to explore an already familiar stimulus. Participant's gaze was tracked as they tried to encode or retrieve a familiar face displayed either alone or alongside other unfamiliar faces. Regardless of the memory task (encoding\retrieval), longer fixation durations were observed when a single familiar face was presented alone, and not when presented among unfamiliar ones. Thus, fixations were not prolonged when it was possible to explore other, unfamiliar stimuli. We conclude that prolonged fixations on familiar stimuli reflect a lesser need to explore an already familiar percept. The results underscore how memory representations influence active sensing, yielding fresh insights into efficient deployment of attention resources. We conclude that fixation durations could be used in applied memory detection tests, preferably together with other measures and when the familiar stimulus is presented alone.