Visual exploration of natural images by saccades. A, Each trial started with the presentation of a central fixation cross for 500 ms. Then followed seven natural images displayed for 4,000 ms. Natural images were shown using either a gray or color scale, and they belong to one of the three different categories: animal, food, or object. The proportion of color and categories were balanced within and between trials. Participants were asked to freely explore the images and eye movements were allowed. Then followed a mask for 2,000 ms, after which the seven images were presented again. One of the images had changed: the different image, belonging to the same category and color scale as the initial one. In this example, the grayscale fox turned into a grayscale cat (6th position). The participants had to identify, without time limit, the image that had changed. A number was presented above each image, as well an imaging showing the link between the image numbers and the response buttons. Each trial was interleaved with a 500–1,000 ms random delay. B, The processing of the color and the category of natural images was investigated in three conditions: (1) The fixated image in the fovea. (2) Upcoming image in the parafovea, corresponding to the image that will be fixated after the saccade. (3) Past image in the parafovea, corresponding to the image that was viewed before the current fixation.