Foulsham et al., 2013; Ossand´ on et al., 2014). This result indicates that the leftward bias is not only present, if participants start observations from the center of the image. 

## Saccade turning angle and its relation to amplitude 

Statistically, most saccades are likely to follow the direction of previous saccades or shift gaze position back to the direction of the starting position of the previous saccade. The overall distribution of saccade turning angles between two subsequent saccades is charac- teristic for similar experiments in scene viewing (Fig.5a) (Tatler & Vincent, 2008; Smith & Henderson, 2009). Next, we constructed a conditional plot of saccade amplitude in relation to the previous saccade amplitude and orientation (Fig.5b). The endpoint of the previous saccade was mapped to the origin of the coordinate system, saccade amplitude was normalized to the amplitude of the previous saccade, and the saccade orientation of the previous saccade was rotated to the right (or 180 ◦ orientation). In this representa- tion, an endpoint at ( x ; y ) = (1; 0) corresponds to a saccade that has the same length and orientation as the previous saccade (i.e., a turning angle of 180 $^{◦}$). The endpoint at ( x ; y ) = ( − 1; 0) indicates that the saccade had the same amplitude as the previous sac- cade , but an opposite direction, which represents a perfect return saccade (i.e., a turning angle of 0 $^{◦}$). The high intensity at this point is consistent with earlier experiments that reported a large number of return saccades (Hooge et al., 2005; Tatler & Vincent, 2008; Smith & Henderson, 2009). 

Results from our analysis of turning angles and saccade amplitudes seem to be inconsis- tent with an inhibitory tagging mechanism. However, ruling out an inhibitory tagging mechanism based on these data would be premature, since inhibitory tagging could still be active, but not express in behavioral data on this level. Our analyses below will indi- cate a potential role of inhibitory tagging. Moreover, Figure 5c shows the same plot as 

