Been there, seen that, done that: Modification of visual exploration across repeated exposures

The underlying factors that determine gaze position are a central topic in visual cognitive research. Traditionally, studies emphasized the interaction between the lowlevel properties of an image and gaze position. Later studies examined the influence of the semantic properties of an image. These studies explored gaze behavior during a single presentation, thus ignoring the impact of familiarity. Sparse evidence suggested that across repetitive exposures, gaze exploration attenuates but the correlation between gaze position and the lowlevel features of the image remains stable. However, these studies neglected two fundamental issues: (a) repeated scenes are displayed later in the testing session, such that exploration attenuation could be a result of lethargy, and (b) even if these effects are related to familiarity, are they based on a verbatim familiarity with the image, or on high-level familiarity with the gist of the scene? We investigated these issues by exposing participants to a sequence of images, some of them repeated across blocks. We found fewer, longer fixations as familiarity increased, along with shorter saccades and decreased gaze allocation towards semantically meaningful regions. These effects could not be ascribed to tonic fatigue, since they did not manifest for images that changed across blocks. Moreover, there was no attenuation of gaze behavior when participants observed a flipped version of the familiar images, suggesting that gist familiarity is not sufficient for eliciting these effects. These findings contribute to the literature on memory-guided gaze behavior and provide novel insights into the mechanism underlying the visual exploration of familiar environments.