TRANSFER OF SHORT-TERM ADAPTATION IN HUMAN SACCADIC EYE-MOVEMENTS
TRANSFER OF SHORT-TERM ADAPTATION IN HUMAN SACCADIC EYE-MOVEMENTS
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DOI：
10.1007/bf00227199
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发表时间：
1994-08-01
影响因子：
2
通讯作者：
VANOPSTAL, AJ
中科院分区：
文献类型：
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作者：
FRENS, MA;VANOPSTAL, AJ
目前存在争议的是，针对特定目标配置的所谓“增益缩短范式”的跳眼系统，在多大程度上将跳眼指标的变化转移到不同情况下引发的跳眼。为了进一步评估这一问题，我们研究了在各种条件下视觉诱导短期适应后人类跳眼运动的特性。我们观察到，与适应前基线相比，适应期间和之后的扫视没有显著改变其主要序列特性。在整个实验过程中，眼跳速度剖面保持正常，没有证据表明校正眼跳在初级眼跳中逐渐被吸收。我们发现短期适应对扫视指标的影响并不局限于用于诱导适应反应的初始眼位和视觉目标的空间位置的特定组合。在不同的初始位置，对具有相同视网膜位置坐标的目标所引发的扫视与在适应阶段产生相同的适应水平。然而，我们的研究结果表明，适应仅限于适应目标中心坐标周围的有限范围的眼跳向量（“限制性适应场”）。较小和较大的眼动具有明显较低的适应值。此外，两个进一步的实验表明，视网膜刺激不是适应表达自身的先决条件：首先，在一个双步实验中，我们将视网膜刺激向量与所需的动眼肌反应分离开来。其次，我们还研究了视觉诱导适应对听觉诱发跳眼的影响。在这两项任务中，适应都被转移到所需的运动反应上。根据我们的研究结果，我们得出结论，短期适应是在多感觉阶段表达的，在这个阶段，跳眼运动被表示为期望的眼位移向量（运动误差）。讨论了可能的神经生理学意义。
Controversy exists as to the extent to which the saccadic system, adapted in the so-called 'gain-shortening paradigm' for a particular target configuration, transfers the resulting change in saccade metrics to saccades elicited under different circumstances. In order to further assess this problem, we investigated the properties of human saccadic eye movements after visually induced short-term adaptation under a variety of conditions. We observed that saccades both during and after the adaptation did not significantly change their main sequence properties with respect to the pre-adaptation baseline. Saccade velocity profiles remained normal throughout the experiment, and we obtained no evidence that correction saccades were gradually absorbed in the primary saccade. We found that the effect of the short-term adaptation on saccade metrics is not confined to the particular combination of initial eye position and spatial position of the visual target used to induce the adaptation response. Saccades elicited from different initial positions towards targets with the same retinotopic coordinates as in the adaptation phase yield the same level of adaptation. However, our findings indicate that adaptation is confined to a limited range of saccade vectors around the oculocentric coordinates of the adaptation target ('restricted adaptation field'). Smaller and larger saccades are endowed with significantly lower adaptation values. Moreover, two further experiments showed that a retinal stimulus is not a prerequisite for adaptation to express itself: First, in a double-step experiment, we dissociated the retinal stimulus vector from the required oculomotor response. Second, we also investigated the effect of visually induced adaptation on auditory evoked saccades. In both tasks the adaptation was transferred to the required motor response. Based on our findings, we conclude that shortterm adaptation is expressed at a multisensory stage, where saccadic eye movements are represented as desired eye displacement vectors (motor error). Possible neurophysiological implications are discussed.