Role of reafferent mechanisms in predictive interactions between head and eye movement.

再传入机制在头部和眼球运动之间的预测相互作用中的作用。

• 批准号: G0601572/1
• 负责人: Graham Barnes
• 金额: $ 70.07万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=G0601572%2F1
• 关键词: Role; reafferent; mechanisms; predictive; interactions

Making smooth pursuit eye movements to track moving objects, such as a flying bird, is a familiar everyday activity. The process involves matching the speed of the eye to that of the target, thereby minimizing movement of the image on the retina and reducing blur. Such anticipatory movements are essential to allow us to overcome delays in visual processing, which otherwise impair tracking ability. Previously, we have shown how such anticipatory movements may be generated by using repeated presentations of identical motion stimuli. This creates a high expectancy of impending target motion and allows smooth anticipatory movements to be developed. The velocity of these anticipatory eye movements is proportional to future target velocity, implying that working memory is used to temporarily store velocity information gleaned from prior experience. Similar anticipatory tracking movements of the head have been found when tracking with head and eyes together. All our previous work in this area has been confined to tracking simple movements along the horizontal axis. In the proposed experiments we plan to investigate how the system operates in more realistic conditions where objects move horizontally, vertically and toward or away from the observer. We will investigate how the brain develops anticipatory control of head and eye movements. We will also determine which areas of the brain are involved in the storage and generation of anticipatory movements by using functional magnetic resonance imaging (fMRI) to record brain activity as human subjects carry out predictable and non-predictable tracking tasks with the eye. In particular, we intend to investigate brain activity when tracking a sequence of such movements in which each component has different speed and direction. Sequence learning is a simple form of motor programming that allows subjects to learn repetitive sequences of movements, such as typing. We have found previously that subjects can learn to generate anticipatory movements to sequences during simple horizontal movement after only one or two presentations, but we expect that when the sequences involve both horizontal and vertical movements more repetitions will be required, because this places greater demands on working memory. Generating anticipatory activity is fundamental to normal motor behaviour and is often disrupted in patients with motor disorders such as Parkinson?s disease or cerebellar degeneration. Findings from the proposed experiments will provide greater understanding of motor control and thus lead to improvements in diagnosis, monitoring of drug treatment and rehabilitation.

通过流畅的追逐眼球运动来跟踪移动的物体，如飞鸟，是一种熟悉的日常活动。这个过程包括使眼睛的速度与目标的速度相匹配，从而使图像在视网膜上的移动最小化，并减少模糊。这样的预期动作对于我们克服视觉处理中的延迟是必不可少的，否则视觉处理就会削弱跟踪能力。在此之前，我们已经展示了如何通过重复呈现相同的运动刺激来产生这种预期运动。这创造了对即将到来的目标运动的高预期，并允许开发出流畅的预期运动。这些预期眼球运动的速度与未来目标的速度成正比，这意味着工作记忆被用来暂时存储从先前经验中收集的速度信息。当用头和眼睛一起跟踪时，也发现了类似的头部预期跟踪运动。我们以前在这一领域的所有工作都局限于跟踪沿水平轴的简单运动。在拟议的实验中，我们计划研究系统如何在更现实的条件下运行，其中对象水平、垂直和朝向或远离观察者移动。我们将研究大脑如何发展对头部和眼睛运动的预期控制。我们还将通过使用功能磁共振成像(FMRI)来记录受试者用眼睛进行可预测和不可预测的跟踪任务时的大脑活动，从而确定大脑中哪些区域参与了预期运动的存储和生成。具体地说，我们打算在跟踪一系列这样的运动时调查大脑活动，在这些运动中，每个组件都有不同的速度和方向。序列学习是运动编程的一种简单形式，允许受试者学习重复的动作序列，如打字。我们之前已经发现，受试者可以在一到两次演示后，在简单的水平动作中学习对序列产生预期动作，但我们预计，当序列既包括水平动作又包括垂直动作时，需要更多的重复，因为这对工作记忆提出了更高的要求。产生预期活动是正常运动行为的基础，在帕金森氏症、S病或小脑变性等运动障碍患者中，这种活动经常受到干扰。拟议的实验结果将提供对运动控制的更多了解，从而改进诊断、监测药物治疗和康复的工作。