Individual subjects’ SSA, namely the median horizontal saccade endpoint when trying to look straight ahead, is depicted by individual circles for all three task phases (N = 6; positive values = right). The blue lines and the boxes reflect across subjects means and SE (to account for our within-subject design, we removed the between-subject variance for calculation of the SE according to the procedure described by Masson and Loftus, 2003). The p-values of pairwise statistical comparisons are indicated in grey boxes. An MVS-induced leftward bias in subjective straight ahead (SSA) is apparent in this diagram. The SSA exhibited a significant leftward shift from the outside 1 to the inside phase (one-tailed paired t-test: t(5)=4.52, p = 0.003, g1[CI95%] = −1.24 [-2.3,–0.11]). This effect vanished after removing subjects from the scanner in the outside 2 phase (one-tailed paired t-test: t(5)=-3.86, p = 0.006, g1[CI95%] = −1.58 [-2.79,–0.31]). There was no significant difference between the SSA for phases outside 1 and 2 (two-tailed paired t-test: t(5)=0.82, p = 0.45, g1[CI95%] = 0.22 [-0.60, 1.02]).