Modulation of saccadic eye movements by predicted reward outcome
Modulation of saccadic eye movements by predicted reward outcome
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DOI：
10.1007/s00221-001-0928-1
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发表时间：
2002-01-01
影响因子：
2
通讯作者：
Hikosaka, O
中科院分区：
文献类型：
--
作者：
Takikawa, Y;Kawagoe, R;Hikosaka, O
奖励是行为的首要目标，对动物的生存至关重要。为了探索这种奖励导向行为背后的机制，我们设计了一个记忆导向的扫视任务，其中四个固定方向中只有一个方向得到奖励，这被称为单向奖励任务（one-direction-reward task, 1DR）。当奖励方向在四个块中改变时，在给定方向上的扫视在一个块中得到奖励（构成奖励导向行为），但在其他块中没有奖励（非奖励导向行为）。作为对照，采用全方向奖励任务（ADR）。使用这些任务，我们发现眼跳参数的变化取决于眼跳之后是否有奖励。(1)与非奖励组相比，奖励组的平均扫视峰速度更高，平均扫视潜伏期更短。(2) 3只猴子中有2只的平均扫视幅度没有差异。(3)奖励条件下的跳速、潜伏期和振幅变化较小。(4)在1DR区间内，有奖励条件下的扫视速度保持较高，无奖励条件下的扫视速度逐渐下降；不良反应仅略有下降。眼跳潜伏期表现出相反的变化模式，但不太明显。(5)在奖励试验后不久，无奖励条件下的扫视具有较慢的速度和较长的潜伏期。(6)非奖励组的错误试验比例明显高于奖励组。(7)由于过早或不正确的扫视导致的错误表现出独特的时空模式，反映了认知过程和动机过程之间的竞争。这些结果为奖励导向行为的神经元机制提供了重要的约束，因为它必须满足这些规则。
Reward is a primary goal of behavior and is crucial for survival of animals. To explore the mechanisms underlying such reward-oriented behavior, we devised a memory-guided saccade task in which only one fixed direction out of four was rewarded, which was called the one-direction-rewarded task (1DR). As the rewarded direction was changed in four blocks, saccades in a given direction were rewarded in one block (constituting reward-oriented behavior), but non-rewarded in the other blocks (non-reward-oriented behavior). As a control, an all-directions-rewarded task (ADR) was used. Using these tasks, we found that the parameters of saccades changed depending on whether or not the saccade was followed by reward. (1) The mean saccadic peak velocity was higher and the mean saccade latency was shorter in the rewarded condition than in the non-rewarded condition. (2) The mean saccade amplitude showed no difference in two out of three monkeys. (3) The variations of saccadic velocity, latency and amplitude were smaller in the rewarded condition. (4) Within a block of 1DR, the saccade velocity remained high in the rewarded condition, but decreased gradually in the non-rewarded condition; it decreased only slightly in ADR. The saccade latency showed the opposite pattern of change, but less clearly. (5) The saccades in the non-rewarded condition tended to have slower velocities and longer latencies in the trials shortly after a rewarded trial. (6) The ratio of error trials was much higher in the non-rewarded condition than the rewarded condition. (7) The errors, which were due to premature or incorrect saccades, showed unique spatiotemporal patterns that would reflect the competition between the cognitive and motivational processes. These results provide important constraints to the neuronal mechanism underlying reward-oriented behavior because it must satisfy these rules.