Primary gaze (A,E), eye (B,F), head contribution (C,G) and total head amplitude (D,H) as a function of trial number for forward (C7) and backward (H2) adaptation sessions when the head and eyes were not aligned. Squares indicate data from gaze shifts made with the eyes initially deviated to the left. Triangles indicate movements made with the eyes initially deviated to the right. Black filled symbols are pre-adaptation trials; gray filled symbols are adaptation trials. Unfilled symbols show the mean (±SD) amplitudes during pre-adaptation trials made directly to the T2 target.