Figure 2.

TMS-induced perturbations in oblique saccades. Data in A–D are from a single subject and E shows group data. The target was turned off at target onset for these experiments, ensuring that compensation of the pause does not depend on visual input. A, Two-dimensional trajectories of oblique saccades. For the TMS perturbed trials, the primary movement (green), the pause period (blue), and the compensatory movement (red) are highlighted. B, Horizontal and vertical position and velocity traces of the same saccades as in A. Note that peak velocity of vertical component of control saccades (no TMS) is less than that of the horizontal component. Blue vertical line denotes time of TMS. C, Compensation in the horizontal and vertical components for paused saccades. The size of the compensatory movement is highly correlated with the distance to target during the pause. Dotted lines denote perfect compensation of the error during the pause. Solid lines show the least mean square fit of actual compensation. D, Peak acceleration of the compensatory movement. The compensatory movements (red) are often slower than saccades of comparable amplitude (black). These control saccades were taken from visually guided corrective saccades during the same experiment in the same subject. E, Group data of saccade amplitude. The final amplitude of the paused saccades after the compensatory movement was larger than control saccades. There were some trials with TMS that did not show a pause (middle bar). These saccades had end positions that were closer to the target than saccades that showed a pause, suggesting that they did not show a correction because the eye was already close to the target. TMS coil was placed over Cz during acquisition of these data.