Boxer Adam L, Garbutt Siobhan, Rankin Katherine P, Hellmuth Joanna, Neuhaus John, Miller Bruce L, Lisberger Stephen G
Department of Neurology, Memory and Aging Center, University of California, San Francisco, California 94143-1207, USA.
J Neurosci. 2006 Jun 7;26(23):6354-63. doi: 10.1523/JNEUROSCI.0549-06.2006.
Deficits in the ability to suppress automatic behaviors lead to impaired decision making, aberrant motor behavior, and impaired social function in humans with frontal lobe neurodegeneration. We have studied patients with different patterns of frontal lobe dysfunction resulting from frontotemporal lobar degeneration or Alzheimer's disease, investigating their ability to perform visually guided saccades and smooth pursuit eye movements and to suppress visually guided saccades on the antisaccade task. Patients with clinical syndromes associated with dorsal frontal lobe damage had normal visually guided saccades but were impaired relative to other patients and control subjects in smooth pursuit eye movements and on the antisaccade task. The percentage of correct antisaccade responses was correlated with neuropsychological measures of frontal lobe function and with estimates of frontal lobe gray matter volume based on analyses of structural magnetic resonance images. After controlling for age, gender, cognitive status, and potential interactions between disease group and oculomotor function, an unbiased voxel-based morphometric analysis identified the volume of a segment of the right frontal eye field (FEF) as positively correlated with antisaccade performance (less volume equaled lower percentage of correct responses) but not with either pursuit performance or antisaccade or visually guided saccade latency or gain. In contrast, the volume of the presupplementary motor area (pre-SMA) and a portion of the supplementary eye fields correlated with antisaccade latency (less volume equaled shorter latency) but not with the percentage of correct responses. These results suggest that integrity of the presupplementary motion area/supplementary eye fields is critical for supervisory processes that slow the onset of saccades, facilitating voluntary saccade targeting decisions that rely on the FEF.
抑制自动行为能力的缺陷会导致额叶神经退行性变患者的决策能力受损、运动行为异常和社交功能障碍。我们研究了因额颞叶变性或阿尔茨海默病导致不同额叶功能障碍模式的患者，调查他们进行视觉引导扫视和平稳跟踪眼球运动以及在反扫视任务中抑制视觉引导扫视的能力。与背侧额叶损伤相关临床综合征的患者视觉引导扫视正常，但在平稳跟踪眼球运动和反扫视任务方面相对于其他患者和对照受试者存在缺陷。反扫视正确反应的百分比与额叶功能的神经心理学测量以及基于结构磁共振图像分析的额叶灰质体积估计值相关。在控制年龄、性别、认知状态以及疾病组和动眼功能之间的潜在相互作用后，基于体素的无偏形态学分析确定右侧额叶眼区（FEF）一段的体积与反扫视表现呈正相关（体积越小，正确反应百分比越低），但与跟踪表现、反扫视或视觉引导扫视潜伏期或增益均无关。相比之下，补充运动前区（pre - SMA）和部分辅助眼区的体积与反扫视潜伏期相关（体积越小，潜伏期越短），但与正确反应的百分比无关。这些结果表明，补充运动前区/辅助眼区的完整性对于减缓扫视起始的监督过程至关重要，有助于依赖额叶眼区的自愿扫视目标决策。
