Figure 4.
Prediction during smooth pursuit. (a) Schematic of the experimental paradigm. After an initial fixation period of 800 ms, the target moved along the forward path for either 1200 or 2400 ms unpredictably (labelled forward). Afterwards, the target retraced its movement back to the starting position (labelled return). The trial ended with a final fixation period. This paradigm allows us to examine anticipation of target motion onset, reversal and end within the same trial. The influence of spatial cues was reduced by randomizing the initial target position. Reproduced with permission from de Hemptinne et al. [65]. (b) Target velocity (dashed curve) and eye velocity (continuous curve) during pursuit of the stimulus depicted in (a). (i): single pursuit trial without significant anticipation. (ii): single pursuit trial with three different anticipatory responses: AS, anticipatory pursuit start before target motion onset (TON); AR, anticipatory deceleration in expectation of a target reversal 1200 ms after motion onset; AE, anticipatory deceleration before the target ends (TOFF). Rev, reversal of the trajectory. Reproduced with permission from de Hemptinne et al. [65].