CONTROL OF VERGENCE EYE MOVEMENTS BY THE FRONTAL CORTEX

研究人员将训练恒河猴执行动眼肌任务，以阐明前冠状皮层（8Ar）内的神经元如何编码双眼刺激的视觉特征，从而引发眼球运动。据报道，视觉引导的会聚眼运动由最初的短暂会聚成分和后来持续的会聚成分组成，该会聚成分“锁定”会聚角，足以使感觉融合发生。这些成分已经在人类身上进行了广泛的研究，但在恒河猴身上还没有。首先，将使用电磁搜索线圈方法对猴子的会聚性眼球运动的这些组成部分进行表征。随后，这些收敛成分和引起它们的感觉刺激将与弓形皮层内神经元记录的单个活动相关联。第一个目标将描述在短暂和持续的收敛过程中，前冠状皮层内神经元的行为。简短呈现的两种图像或长时间呈现的不同图像将会把瞬态辐散与持续辐散区分开来。2。第二个目标将更密切地观察由前冠状皮层内的神经元编码的视觉特征。将使用强制选择范例来确定目标特性（例如亮度，方向，空间频率）影响瞬态收敛和神经活动。3。最后的目标是使用二元刺激，在瞬态收敛过程中根据局部和全局线索分离双眼匹配。相关的动态随机点立体图将测试预交神经元如何对这些全局视差线索作出反应。这个项目的结果将提高我们对与斜视和会聚功能障碍相关的神经功能缺陷的理解。

Alert, rhesus monkeys will be trained to perform oculomotor tasks to clarify how neurons within the prearcuate cortex (8Ar) encode the visual characteristics of binocular stimuli that elicit vergence eye movements. Visually-guided vergence eye movements are reported to be composed of an initial transient vergence component and a later, sustained fusional component that "locks" vergence angle sufficiently for sensory fusion to occur. These components have been studied extensively in humans but not in the rhesus monkey. Initially, these components of vergence eye movements will be characterized in monkeys using the electromagnetic search coil method. Subsequently, these vergence components and the sensory stimuli eliciting them will be correlated with single-unit activity recorded from neurons within the prearcuate cortex. I. The first aim will characterize the behavior of neurons within the prearcuate cortex during the transient and sustained components of vergence. Briefly presented dichoptic images or long presentations of dissimilar images will separate transient vergence from sustained vergence. II. The second aim will look more closely at those visual characteristics encoded by neurons within the prearcuate cortex. A forced-choice paradigm will be used to determine what target characteristics (e.g. luminance, orientation, spatial frequency) affect transient vergence and neural activity. III. The final aim uses dichoptic stimuli that dissociate binocular matches based on local and global cues during transient vergence. Correlated, dynamic random-dot stereograms will test how prearcuate neurons respond to these global disparity cues. The results of this project will improve our understanding of neurological deficits associated with strabismus and of vergence dysfunction.