Monkeys with selective bilateral lesions of area MT were trained on tasks designed to examine visuomotor function. They were required to: 1- retrieve a small food pellet from a narrow slot; 2- locate and retrieve a loose peanut mounted on a background of fixed peanuts; and 3- retrieve an erratically moving food pellet from a spinning bowl. After the lesions, these monkeys were behaviorally impaired relative to their own preoperative performances and also relative to the postoperative performances of the control monkeys with lesions in optic radiation fibers (OR) under MT or lesions in the posterior parietal cortex (PP). Although their performance improved with practice and time, the MT-lesioned monkeys showed long-term impairments twenty weeks after surgery. Control monkeys performed no worse on the tasks after their lesions. Another task which required the monkeys to retrieve a food pellet without visual guidance revealed that all the animals performed equally poorly when visual cues were unavailable, but that only the control monkeys benefited when visual cues were available. None of the monkeys were impaired on a pattern discrimination learning task. Besides that, direct observations revealed that the MT-lesioned animals grasped peanuts in a manner different from the control animals.

具有选择性双侧 MT 区域病变的猴子接受了旨在检查视觉运动功能的任务的训练。他们被要求： 1- 从狭窄的槽中取出一个小的食物颗粒；2- 找到并取回安装在固定花生背景上的松散花生；和 3- 从旋转碗中取出不规则移动的食物颗粒。损伤后，这些猴子相对于它们自己的术前表现以及与具有 MT 下视辐射纤维 (OR) 病变或后顶叶皮层 (PP) 病变的对照猴子的术后表现相比，行为受损。虽然他们的表现随着练习和时间的推移而提高，但 MT 损伤的猴子在手术后 20 周表现出长期损伤。对照猴子在病变后的任务中表现并不差。另一项要求猴子在没有视觉指导的情况下取回食物颗粒的任务表明，当视觉提示不可用时，所有动物的表现同样差，但只有对照猴子在视觉提示可用时受益。没有一只猴子在模式辨别学习任务中受到损害。除此之外，直接观察表明，受 MT 损伤的动物以不同于对照动物的方式抓住花生。