Role of arcuate frontal cortex of monkeys in smooth pursuit eye movements. I. Basic response properties to retinal image motion and position.
Role of arcuate frontal cortex of monkeys in smooth pursuit eye movements. I. Basic response properties to retinal image motion and position.
复制标题
猴子弓形额叶皮层在平滑追踪眼球运动中的作用。
DOI：
10.1152/jn.2002.87.6.2684
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发表时间：
2002
影响因子：
2.5
通讯作者：
Lisberger,StephenG
中科院分区：
文献类型：
--
作者：
Tanaka,Masaki;Lisberger,StephenG
解剖学和生理学研究表明，猕猴弓状皮质的“额叶追踪区”(FPA)参与控制顺畅追赶眼球运动。为了进一步分析FPA携带的信号，我们检查了在各种眼球运动任务中，从弓状刺附近的离散区域记录的与追踪相关的神经元的活动。追踪神经元表现出方向调谐，优先选择的方向范围较大，半峰值的平均全宽为129°。用“接收器工作特性”来比较目标在相反方向运动的反应时的潜伏期分析表明，58%的FPA神经元的方向性反应导致了追逐的启动，而19%的FPA神经元的方向性反应导致了25ms或更长时间的追逐。对某一目标速度范围内的神经元反应的分析表明，启动追踪时对眼速的敏感度大于追踪维持时的敏感度，这与与图像运动和眼动有关的两种放电成分相一致。FPA神经元表现出与先前报道的两种追踪行为特征的相关性。1)追踪开始时的眼球加速随着运动目标的偏心而下降。FPA神经元在追逐开始时表现出放电减少，与眼球加速的下降平行。这一发现与先前的观点是一致的，即FPA在调节视觉-运动传递的增益方面起作用。2)静止的偏心线索能唤起与线索方向相反的顺畅的眼球运动，并增强后续目标运动所引起的追逐。FPA内的许多追踪神经元对静止目标表现出微弱的相位性视觉反应，并被调谐到与优先追踪方向相反的一侧偏心约4°的位置。然而，在眼跳的准备或执行过程中，很少有神经元(12%)有反应。对静止目标的反应可以解释静止的、古怪的线索的行为效应。进一步分析正反向追踪过程中视网膜位置误差与放电率之间的关系，未能提供图像位置对FPA神经元放电有较大贡献的证据。我们的结论是，FPA根据图像和眼速来处理信息，它在功能上独立于视跳前视场，后者根据视网膜图像位置来处理信息。
Anatomical and physiological studies have shown that the “frontal pursuit area” (FPA) in the arcuate cortex of monkeys is involved in the control of smooth pursuit eye movements. To further analyze the signals carried by the FPA, we examined the activity of pursuit-related neurons recorded from a discrete region near the arcuate spur during a variety of oculomotor tasks. Pursuit neurons showed direction tuning with a wide range of preferred directions and a mean full width at half-maximum of 129°. Analysis of latency using the “receiver operating characteristic” to compare responses to target motion in opposite directions showed that the directional response of 58% of FPA neurons led the initiation of pursuit, while 19% led by 25 ms or more. Analysis of neuronal responses during pursuit of a range of target velocities revealed that the sensitivity to eye velocity was larger during the initiation of pursuit than during the maintenance of pursuit, consistent with two components of firing related to image motion and eye motion. FPA neurons showed correlates of two behavioral features of pursuit documented in prior reports.1) Eye acceleration at the initiation of pursuit declines as a function of the eccentricity of the moving target. FPA neurons show decreased firing at the initiation of pursuit in parallel with the decline in eye acceleration. This finding is consistent with prior suggestions that the FPA plays a role in modulating the gain of visual-motor transmission for pursuit.2) A stationary eccentric cue evokes a smooth eye movement opposite in direction to the cue and enhances the pursuit evoked by subsequent target motions. Many pursuit neurons in the FPA showed weak, phasic visual responses for stationary targets and were tuned for the positions about 4° eccentric on the side opposite to the preferred pursuit direction. However, few neurons (12%) responded during the preparation or execution of saccades. The responses to the stationary target could account for the behavioral effects of stationary, eccentric cues. Further analysis of the relationship between firing rate and retinal position error during pursuit in the preferred and opposite directions failed to provide evidence for a large contribution of image position to the firing of FPA neurons. We conclude that FPA processes information in terms of image and eye velocity and that it is functionally separate from the saccadic frontal eye fields, which processes information in terms of retinal image position.