Saccadic instabilities and voluntary saccadic behaviour
Saccadic instabilities and voluntary saccadic behaviour
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DOI：
10.1007/s00221-004-2209-2
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发表时间：
2005-07-01
影响因子：
2
通讯作者：
Abadi, RV
中科院分区：
文献类型：
--
作者：
Gowen, E;Abadi, RV
主注视注视从来不是完全稳定的，但可以被无意识的共轭扫视侵入（SI）打断。SI在正常人群中具有很高的患病率，并且其特征在于远离期望的眼睛位置的水平快速眼睛运动，在可变的持续时间之后，接着是返回扫视或漂移。振幅通常低于1度，并且它们通常表现出方向性偏差。本研究的目的是调查与扫视行为有关的SI的病因。有人假设，如果SI是由扫视系统中的缺陷（即抑制机制降低）引起的，则自愿扫视行为的变化可能是明显的，并且与SI频率相关。为了检验这一点，对十名正常受试者进行了同步（无间隙）、间隙、重叠和反跳跃任务。SI频率与随意眼跳延迟、快速眼跳百分比和反眼跳错误百分比之间没有显著相关。此外，SI方向偏差与眼跳潜伏期方向偏差、快速眼跳偏差和反眼跳错误偏差之间均无显著相关。这些结果表明，一个潜在的改变扫视行为是不太可能参与SI生产，SI命令信号可能会产生一个完整的扫视系统的影响，注意。具体而言，与注意力水平和方向相关的下行离皮质信号可能会改变注视和扫视生成之间的平衡，从而确定SI特征。
Primary gaze fixation is never perfectly stable but can be interrupted by involuntary, conjugate saccadic intrusions (SI). SI have a high prevalence in the normal population and are characterised by a horizontal fast eye movement away from the desired eye position, followed, after a variable duration, by a return saccade or drift. Amplitudes are usually below 1 degrees and they often exhibit a directional bias. The aim of the present study was to investigate the aetiology of SI in relation to saccadic behaviour. It was hypothesised that if SI resulted from deficits in the saccadic system (i.e. reduced inhibitory mechanisms), changes in voluntary saccade behaviour may be apparent and related to SI frequency. To examine this, synchrony (no gap), gap, overlap and antisaccade tasks were conducted on ten normal subjects. No significant correlations were found between SI frequency and voluntary saccade latencies, the percentage of express saccades, or the percentage of antisaccade errors. In addition, no significant correlations were found between SI directional biases and saccade latency directional biases, express saccade biases or antisaccade error biases. These results suggest that an underlying alteration to saccadic behaviour is unlikely to be involved in SI production, and that the SI command signal may arise from the influence of attention on an intact saccadic system. Specifically, descending corticofugal signals relating to attention level and orientation may alter the balance between fixation and saccade generation, so determining SI characteristics.