The control of rapid limb movement in the cat. IV. Updating of ongoing isometric responses.
The control of rapid limb movement in the cat. IV. Updating of ongoing isometric responses.
复制标题
猫快速肢体运动的控制。
DOI：
10.1007/bf00240507
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发表时间：
1984
影响因子：
2
通讯作者：
Ghez,C
中科院分区：
文献类型：
--
作者：
Vicario,DS;Ghez,C
1.被训练为通过快速、等长的力量调整来跟踪移动显示的猫，其反应的特点是反应时间极短(60-70ms)和刻板印象的时间结构。动物使用展示运动的早期导数来根据初始展示运动与所需力量之间的已知关系来衡量对不同大小目标刺激的力反应(Ghez和Vicario 1978a，1978b)。在本研究中，我们通过使用双重刺激和延迟反馈来改变这种关系，以评估动物更新其反应的能力。2.在随机试验的受控间隔(15-120ms)后，第二个目标刺激紧跟第一个目标刺激的实验中，动物在反应时间很少或没有增加的情况下，沿着适当的方向修改其反应。当第二个刺激要求回到基线时，动物中止了正在进行的反应。当第二次刺激需要加倍刺激时，动物的相位力输出增加；然而，这种增加不足以达到新的目标水平，并发出迟发反应。3.每次实验双刺激试验后的对照反应在峰力和峰df/dt的幅度上与其他对照组一致。要求返回的试验后的对照反应大小减小；需要反应加倍的刺激后的对照反应增加。我们的结论是，实验不仅引起了正在进行的反应的修改，而且还导致动物改变了将初始显示导数与所需力量联系起来的内化增益函数。4.在给出第一个目标刺激后反馈延迟的实验中，动物在第一个目标刺激后70-80ms发出新的更新反应。导致猫在延迟反馈试验中更新反应的显示轨迹与反应时间较长的对照试验相同。然而，在这种情况下，必须根据动物对跟踪任务的经验，将引起反应更新的信息推导为实际显示轨迹与动物预期轨迹之间的差异。这表明动物形成了一个显示属性的内部模型，用于确定何时需要新的反应。
1.In cats trained to track a moving display by making rapid, isometric force adjustments, responses are characterized by extremely short reaction times (60–70 ms) and a stereotyped temporal configuration. The animal uses early derivatives of display movement to scale force responses to target stimuli of different sizes according to a learned relationship between initial display motion and required force (Ghez and Vicario 1978a, 1978b). In the present study we altered that relationship by using double stimulation and delayed feedback to assess the animals' ability to update their responses.2.In experiments where a second target stimulus followed the first after a controlled interval (15–120 ms) on random trials, the animal modified its response in the appropriate direction with little or no increase in reaction time. When the second stimulus called for a return to baseline, the animal aborted the ongoing response. When the second stimulus called for a doubling of force, the animal increased its phasic force output; however, this increase was not sufficient to reach the new target level and late responses were emitted.3.The control response which followed each experimental double stimulation trial showed consistent differences from other controls in the amplitude of both peak force and peak dF/dt. Control responses following trials calling for a return were reduced in size; those following stimuli requiring response doubling were increased. We concluded that the experimental trials not only elicited modification of ongoing responses but also caused the animal to alter its internalized gain function relating initial display derivatives to required force.4.In experiments where feedback was delayed after giving a first target stimulus such that the compensatory display failed to reflect the animal's initial response, the animal emitted a new updated response 70–80 ms after the first. The display trajectory which caused the cat to update its response on delayed feedback trial was identical to that of control trials with long reaction times. In this case, however, the information eliciting response updating had to be derived as a difference between the actual display trajectory and that expected by the animal, based on its experience with the tracking task. This suggests that the animal develops an internal model of display properties which is used to determine when a new response is required.