When reaching for an object with the hand, the gaze is usually directed at the target. In a laboratory setting, fixation is strongly maintained at the reach target until the reaching is completed, a phenomenon known as "gaze-anchoring". While conventional accounts of such tight eye-hand coordination have often emphasized the internal synergetic linkage between both motor systems, more recent optimal control theories regard motor coordination as the adaptive solution to task requirements. We here investigated to what degree gaze control during reaching is modulated by task demands. We adopted a gaze-anchoring paradigm in which participants had to reach for a target location. During the reach, they additionally had to make a saccadic eye movement to a salient visual cue presented at locations other than the target. We manipulated the task demands by independently changing reward contingencies for saccade reaction time (RT) and reaching accuracy. On average, both saccade RTs and reach error varied systematically with reward condition, with reach accuracy improving when the saccade was delayed. The distribution of the saccade RTs showed two types of eye movements: fast saccades with short RTs, and voluntary saccade with longer RTs. Increased reward for high reach accuracy reduced the probability of reflexive fast saccades, but left their latency unchanged. The results suggest that gaze-anchoring acts through a suppression of fast saccades, a mechanism that can be adaptively adjusted to the current task demands.

中文翻译：

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灵活调节到达过程中的视线控制以优化任务结果

当用手伸手去拿一个物体时，视线通常会指向目标。在实验室环境中，在到达目标之前，固定强烈地保持在到达目标上，这种现象被称为“凝视锚定”。虽然对这种紧密的眼手协调的传统解释通常强调两个运动系统之间的内部协同联系，但最近的最优控制理论将运动协调视为任务要求的自适应解决方案。我们在这里研究了在到达过程中的凝视控制在多大程度上受到任务需求的调节。我们采用了凝视锚定范式，参与者必须到达目标位置。在到达过程中，他们还必须对在目标以外的位置呈现的显着视觉提示进行眼跳。我们通过独立改变眼跳反应时间 (RT) 的奖励意外事件和达到准确性来操纵任务需求。平均而言，扫视 RT 和到达误差都随奖励条件而系统地变化，当扫视延迟时，到达准确度会提高。扫视 RT 的分布显示出两种类型的眼球运动：具有短 RT 的快速扫视和具有较长 RT 的自愿扫视。对高到达精度的奖励增加降低了反射性快速扫视的可能性，但保持其延迟不变。结果表明，凝视锚定通过抑制快速扫视起作用，这是一种可以根据当前任务需求自适应调整的机制。扫视 RT 和到达误差都随着奖励条件而系统地变化，当扫视延迟时，到达精度会提高。扫视 RT 的分布显示出两种类型的眼球运动：具有短 RT 的快速扫视和具有较长 RT 的自愿扫视。对高到达精度的奖励增加降低了反射性快速扫视的可能性，但保持其延迟不变。结果表明，凝视锚定通过抑制快速扫视起作用，这是一种可以根据当前任务需求自适应调整的机制。扫视 RT 和到达误差都随着奖励条件而系统地变化，当扫视延迟时，到达精度会提高。扫视 RT 的分布显示出两种类型的眼球运动：具有短 RT 的快速扫视和具有较长 RT 的自愿扫视。对高到达精度的奖励增加降低了反射性快速扫视的可能性，但保持其延迟不变。结果表明，凝视锚定通过抑制快速扫视起作用，这是一种可以根据当前任务需求自适应调整的机制。对高到达精度的奖励增加降低了反射性快速扫视的可能性，但保持其延迟不变。结果表明，凝视锚定通过抑制快速扫视起作用，这是一种可以根据当前任务需求自适应调整的机制。对高到达精度的奖励增加降低了反射性快速扫视的可能性，但保持其延迟不变。结果表明，凝视锚定通过抑制快速扫视起作用，这是一种可以根据当前任务需求自适应调整的机制。