Van der Veer Institute for Parkinson's & Brain Research, 66 Stewart Street, Christchurch, New Zealand.
Eur J Neurosci. 2011 Jun;33(11):2091-100. doi: 10.1111/j.1460-9568.2011.07697.x.
Numerous studies have shown that Parkinson's disease (PD) affects the ability to generate voluntary saccades and the ability to suppress reflexive saccades. The effects of PD on the generation of reflexive saccades, however, are not clear. Some studies report impairments, but there are also reports of abnormal facilitation or hyper-reflexivity of the saccade system in PD. Meanwhile, it has been reported that the concurrent performance of a perceptual discrimination task facilitates saccade initiation and reduces saccade latencies in healthy subjects [A. Montagnini & L. Chelazzi (2005)Vis. Res., 45, 3391-3401; L. Trottier & J. Pratt (2005)Vis. Res., 45, 1349-1354]. To investigate the circumstances under which the saccade system may appear hyper-reflexive in PD, we compared reflexive saccades with and without a concurrent perceptual discrimination task in 20 PD patients and 20 controls. Without the discrimination task, the PD group produced reflexive saccades at normal latencies. The discrimination task reduced saccade latencies more in the PD group than in the control group, resulting in abnormally short mean reflexive saccade latencies in the PD group. The discrimination task increased saccade gain in both groups, but saccades in the PD group remained hypometric as compared with saccades in the control group. We conclude that the attentional demands of this paradigm revealed a hypersensitivity to visual inputs in the PD group.
许多研究表明，帕金森病（PD）会影响自愿性扫视的产生能力和反射性扫视的抑制能力。然而，PD 对反射性扫视产生的影响并不明确。一些研究报告称存在障碍，但也有研究报告称 PD 患者的扫视系统存在异常促进或高反射性。同时，据报道，在健康受试者中，同时执行知觉辨别任务可以促进扫视起始并缩短扫视潜伏期[A. Montagnini 和 L. Chelazzi（2005），视觉研究，45，3391-3401；L. Trottier 和 J. Pratt（2005），视觉研究，45，1349-1354]。为了研究 PD 患者的扫视系统可能出现高反射性的情况，我们在 20 名 PD 患者和 20 名对照组中比较了带有和不带有同时进行的知觉辨别任务的反射性扫视。在没有辨别任务的情况下，PD 组产生的反射性扫视潜伏期正常。辨别任务使 PD 组的扫视潜伏期比对照组缩短更多，导致 PD 组的平均反射性扫视潜伏期异常缩短。辨别任务增加了两组的扫视增益，但与对照组相比，PD 组的扫视仍不足。我们得出结论，该范式的注意力需求揭示了 PD 组对视觉输入的过度敏感。
