Effects of motivational conflicts on visually elicited saccades in monkeys.
Effects of motivational conflicts on visually elicited saccades in monkeys.
复制标题
动机冲突对猴子视觉诱发眼跳的影响。
DOI：
10.1007/s00221-003-1555-9
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
Hikosaka,Okihide
中科院分区：
文献类型：
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作者：
Watanabe,Katsumi;Lauwereyns,Johan;Hikosaka,Okihide
由外部刺激引起的奖赏前景是目标导向行为的核心要素。为了阐明奖励期望对眼跳潜伏期的行为影响，我们采用了一个视觉引导的眼跳任务，具有不对称的奖励时间表。猴子在每次试验中都必须立即扫视周边视觉目标，但只对四个可能的目标位置之一进行正确的扫视。奖励的可用性是可预测的基础上的空间位置的目标在整个日常会话。与所有位置都得到少量奖励的条件相比，当眼跳朝向与奖励相关的位置时，不对称奖励时间表中的平均眼跳潜伏期显著短于当眼跳朝向无奖励位置时。此外，对累积潜伏期分布的分歧点分析表明，奖励的期望促进眼跳在所有的潜伏期范围。相比之下，预期的缺乏奖励延迟启动眼跳与lasting长于约200毫秒，无论眼跳是正交或相反的奖励位置的位置。对于具有大于约240 ms的延迟的扫视，当扫视进行到与奖励位置正交相比相反的位置时，观察到额外的延迟。这些结果表明，促进预测奖励是由一个准备过程，是特定的位置介导的，而抑制奖励的情况下，需要约200毫秒后，目标发病成为有效的，最初是位置非特异性，但随着时间的推移变成特定的位置。
The prospect of reward evoked by external stimuli is a central element of goal-oriented behavior. To elucidate behavioral effects of reward expectation on saccade latency, we employed a visually guided saccade task with asymmetrical reward schedule. The monkey had to make an immediate saccade to a peripheral visual target in every trial, but was rewarded for a correct saccade to only one of four possible target positions. Reward availability was predictable on the basis of the spatial position of the target throughout a daily session. Compared with the condition where all positions were rewarded with a smaller amount, the mean saccade latency in the asymmetrical reward schedule was significantly shorter when the saccade was made toward the position associated with reward than when it was directed to no-reward positions. Furthermore, a divergence-point analysis on cumulative latency distributions showed that the expectation of reward facilitated saccades at all latency ranges. In contrast, the expected lack of reward delayed the initiation of saccades with latencies longer than about 200 ms, irrespective of whether the saccade was made to a position orthogonal or opposite to the reward position. For saccades with latencies of more than approximately 240 ms, an additional delay was observed when the saccade was made to a position opposite, as compared to orthogonal, to the reward position. These results suggest that the facilitation by predictive reward is mediated by a preparatory process that is location-specific, whereas the inhibition by the absence of reward takes about 200 ms after the target onset to become effective and is initially location nonspecific but turns location-specific over time.