Schweizer Tom A, Alexander Michael P, Cusimano Michael, Stuss Donald T
Rotman Research Institute, Baycrest, 3560 Bathurst Street, Toronto, Ont. M6A 2E1, Canada.
Neuropsychologia. 2007 Oct 1;45(13):3068-74. doi: 10.1016/j.neuropsychologia.2007.05.018. Epub 2007 Jun 13.
The presence, and nature, of any role of the cerebellum in complex, non-motor behaviors is only beginning to be uncovered. We investigated the non-spatial temporal dynamics of attention in 11 patients with chronic focal lesions to the cerebellum using a rapid serial visual presentation task known as the attentional blink paradigm. In this task two targets are embedded in a letter stream presented at central fixation for identification and the delay between the targets is manipulated. Patients demonstrated an unequivocal disturbance in rapid visual attention as indicated by an increased magnitude of the attentional blink (i.e., more impaired at detecting target 2 when presented in close contiguity to target 1) compared to 13 healthy controls. The attentional blink effect was not significantly protracted in our patients, suggesting a time-limited deficit in resource allocation during temporally demanding stimulus processing conditions. Recovery rate from the attentional blink was the same for our patients and controls implying intact selective attention following cerebellar damage. Because of the experimental design, the results of the present study could not be accounted for by motor dysfunction or saccadic dysmetria. These data provide evidence implicating the cerebellum as a critical node in the neuroanatomical network underlying visuotemporal attention and provide further evidence for the role of the cerebellum in non-motor behaviors.
小脑在复杂非运动行为中的任何作用及其性质才刚刚开始被揭示。我们使用一种称为注意瞬脱范式的快速序列视觉呈现任务,研究了11例小脑慢性局灶性病变患者的非空间时间注意动态。在这个任务中,两个目标嵌入在中央注视呈现的字母流中以供识别,并且目标之间的延迟是可操控的。与13名健康对照相比,患者表现出快速视觉注意的明确障碍,表现为注意瞬脱的幅度增加(即当目标2紧邻目标1呈现时,检测目标2的能力受损更严重)。我们的患者中注意瞬脱效应没有明显延长,这表明在时间要求较高的刺激处理条件下,资源分配存在限时性缺陷。患者和对照从注意瞬脱中的恢复率相同,这意味着小脑损伤后选择性注意保持完整。由于实验设计,本研究结果不能用运动功能障碍或眼球运动失调来解释。这些数据提供了证据,表明小脑是视觉时间注意基础神经解剖网络中的关键节点,并为小脑在非运动行为中的作用提供了进一步证据。