Rothkegel et al. 26 values were estimated in Experiment 3, where the size of the image in degree of visual angle was larger than the other experiments (see General Methods). Scene Walk Model . This recently published saccade generation model (Engbert et al., 2015) proposes that eye movements are driven by two different time-dependent neural activation maps. A fixation map memorizes previous fixations and tags visited fixations locations, making them less probable to be fixated again shortly afterwards. Thus, this map serves as an inhibition of return mechanism (Itti & Koch, 2001; Klein, 2000). A second map, the attention map, reflects the attentional allocation on the given scene for a speficic fixation position. To compute the attention map, first an intermediate map is computed by multiplying a two dimensional Gaussian distribution centered at the current fixation position with the empirical saliency map of the image to reflect the reduced processing in the periphery. The influence of attention maps from previous fixations declines over time and thus the previous attention map is increasingly replaced by the map of the new fixation. An equivalent mechanism is used to control the dynamics of inhibition, i.e., the fixation map. The attention and inhibition maps prior to the first fixation are set to uniform distributions. After computation of the two maps for the current fixation position and duration, they are combined by subtracting the fixation map from the attention map to a target map. After the maps are combined, a target is chosen proportional to the relative activations (Luce, 1959) of the target map. Thus, positions where the fixation map is high whereas the attention map is low are rarely fixated and vice versa. Model parameters where chosen as in the published version of the SceneWalk model (Engbert et al., 2015). Two differences to the original publication were that i) we only computed new maps for each new fixation instead of computing new maps every Δ t = 10 ms . This was done because we chose fixation durations from the