抄録
The smooth pursuit system interacts with the vestibular system to maintain the visual target on the fovea. To investigate whether vestibular inputs contribute to predictive smooth pursuit especially to the timing of its initiation, we measured the latency of smooth pursuit during whole body rotation. Two male Japanese monkeys (Macaca fuscata, K, M) were rotated trapezoidally in the yaw plane (20°/s, ±10°) with a random inter-trial interval. A laser spot was projected onto the tangent screen and moved vertically with a constant delay ranging from 100 to 700ms from chair onset. The delay was given as a block and the monkeys were required to pursue the spot. After this training for 40-60 min, the tracking target was briefly (500-700ms) extinguished ("target blanked") at 80ms after the onset of chair rotation. Latencies of smooth pursuit with or without target blanking were compared with those before training. When the delays of target onset from chair were 100, 300, 500, and 700ms, mean latencies of pursuit of each monkey without target blanking were 87, 208, 352, and 521ms (K), and 88, 134, 365, and 365ms (H), respectively. The latencies of pursuit with target blanking were similar. These results indicate that smooth pursuit was initiated before the onset of target motion with the latencies proportional to the delays used for training even without the presence of the target, suggesting that the monkeys predicted the timing of pursuit initiation with the use of vestibular input. [Jpn J Physiol 54 Suppl:S181 (2004)]
