Reaches with overlapping stimulus-response spatial relations (propointing) adhere to speed-accuracy relations as defined by Paul Fitts' index of difficulty equation (IDFitts: in bits of information). This movement principle is attributed to response mediation via the "fast" visuomotor networks of the dorsal visual pathway. It is, however, unclear whether the executive demands of dissociating stimulus-response spatial relations by reaching mirror-symmetrical to a target (antipointing) elicits similar adherence to Fitts' equation. Here, pro- and antipointing responses were directed to a constant target amplitude with varying target widths to provide IDFitts values of 3.0, 3.5, 4.3, and 6.3 bits. Propointing movement times linearly increased with IDFitts-a result attributed to visually based trajectory corrections. In contrast, antipointing movement times, deceleration times, and endpoint precision did not adhere to Fitts' equation. These results indicate that antipointing renders a "slow" and offline mode of control mediated by the visuoperceptual networks of the ventral visual pathway.

中文翻译：

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反指向范围不符合Fitts（1954）公式的基于宽度的操作。

重叠的刺激响应空间关系（命中点）达到了由Paul Fitts的难度系数方程定义的速度精度关系（IDFitts：以信息为单位）。该运动原理归因于通过背侧视觉通路的“快速”视觉运动网络的反应介导。但是，尚不清楚通过与目标成镜像对称（指向目标）来分离刺激-响应空间关系的执行要求是否会引起对Fitts方程的相似遵循。在此，前指向和反指向响应指向具有可变目标宽度的恒定目标幅度，以提供3.0、3.5、4.3和6.3位的IDFitts值。预期的移动时间随IDFitts线性增加-这归因于基于视觉的轨迹校正。相反，反点运动时间，减速时间和终点精度不符合Fitts方程。这些结果表明，反指向提供了由腹侧视觉通路的视感受网络介导的“慢速”和离线控制模式。