Figure 1.
A: Schematic illustrations of selected experimental conditions.
Hand movement (H), the starting position (SP) and the target (T) are shown for each condition. Visual feedback (FB) of the hand movement (C) is displayed in the baseline and practice conditions, but not in the pre-test 1, post-test 1 and post-test 2 conditions. Tasks are performed in a veridical-feedback environment for the baseline, pre-test 1 and post-test 2 and in a rotated-feedback environment for the practice and post-test 1. Participants are informed of the type of feedback environment at the beginning of each condition. B: An illustration of calculating adaptive shift and after-effect based on the pre-test 1 and post-tests 1 & 2. The angular deviation (AD) is calculated from the SP-T line to the direction of the hand movement. Adaptive shift (or after-effect) is calculated by subtracting AD1 from AD2 (or AD3). See more details in the text.
Table 1.
Experimental conditions.
Figure 2.
Different gaze areas used for analysis of gaze locations.
Five black dots indicate the starting position (SP), the target (T), the hand target (HT), the inverted target (IT), and the cursor (C) positions. The HT position is the hand location that would bring the cursor to the target under the rotated visual feedback (example shown for the 75° rotation). The IT position is the 180° inverted location of the target. The starting position (SP) area, the cursor (C) area, and the target vicinity have a circular shape. The mid area is an area between the SP and target vicinity. The hand-target (HT) area and the inverted-target (IT) area have the same shape as the combined area of the target vicinity and the mid area.
Figure 3.
Adaptive changes of movement time (A), total trajectory length (B) and initial direction error (C) for hand movements during practice of a visuomotor rotation.
Mean values of all participants are plotted against 40 trial blocks with 4 trials each for the 30° (white diamonds), 75° (black circles), and 150° (grey squares) groups. Mean values from the baseline condition (BL) are also plotted. The error bars represent standard errors.
Figure 4.
Adaptive shifts, after-effects and explicit shifts.
Histograms of the adaptive shits (left column), after-effects (center column), and explicit shifts (right column) are plotted for the 30° (A-C), 75° (D-F), and 150° (G-I) groups. The binning size of each plot is 2°.
Figure 5.
Adaptive changes of gaze anchoring behavior.
Hand trajectory length in the pre-gaze anchoring (Pre-GA) period is plotted against block of trials during practice of a visuomotor rotation. The values are expressed as a percentage of the total trajectory length. Formats of the plot are the same as in Fig. 3. The error bars represent standard errors.
Figure 6.
Adaptive changes of hand movement time (A) and gaze locations (B-H) in the pre-gaze anchoring (Pre-AG) period during practice of a visuomotor rotation.
Gaze durations are plotted for different areas of work space (Fig. 2): the target vicinity (B), the mid area excluding (w/o) an overlap with the cursor area (C), the cursor area within the mid area (D), the cursor area (E), the cursor area excluding overlaps with the mid and starting position (SP) area (F), and other area (H). The other area is the work space outside the target vicinity, mid, cursor, SP, hand-target, and inverted-target areas (see Fig. 2 for details). Gaze duration is expressed as the percentage of the pre-GA period. Formats of the plots are the same as in the part related to the practice condition of Fig. 3. The error bars represent standard errors.
Figure 7.
Adaptive changes of average distance between the feedback cursor and gaze location during the pre-gaze anchoring (Pre-GA) period.
The format of the plot is the same as in the part related to the practice condition of Fig. 3. The error bars represent standard errors.