Petersen S E, Robinson D L, Currie J N
Laboratory of Sensorimotor Research, National Eye Institute, Bethesda, MD 20892.
Exp Brain Res. 1989;76(2):267-80. doi: 10.1007/BF00247887.
Several brain areas have been identified with attention, because damage to these regions leads to neglect and extinction. We have tested elements of visual attentional processing in patients with parietal, frontal, or temporal lesions and compared their responses to control subjects. Normal humans respond faster in a reaction time task when the spatial location of a target is correctly predicted by an antecedent stimulus (valid cue) than when the location is incorrectly predicted (invalid cue). The cue is hypothesized to shift attention towards its location and thereby facilitate or impede response latencies. The reaction times of individuals with damage to the parietal lobe are somewhat slowed for targets ipsilateral or contralateral to the side of the lesion if the targets are preceded by valid cues. These same patients are extremely slow in responding to targets in the visual field contralateral to the lesion when the cue has just appeared in the unaffected (ipsilateral) visual field. In addition, these individuals are especially slow in responding to targets in either visual field when the lights are preceded by weak, diffuse illumination of the entire visual field. Patients with lesions of the frontal lobe have very slow reaction times in general and, as is the case for patients with lesions of the temporal lobe, are slow in all conditions for targets in the field contralateral to the lesion. These patterns are probably not associated with attentional defects. For patients with parietal lesions, these studies demonstrate a further deficit in a cued reaction-time task suggesting abnormal visual attention. Since different sites of brain damage yield different patterns of responses, tests such as these could be of analytic and diagnostic value.
多个脑区已被确定与注意力有关，因为这些区域受损会导致忽视和消退。我们对患有顶叶、额叶或颞叶病变的患者进行了视觉注意力加工要素的测试，并将他们的反应与对照组受试者进行了比较。在反应时间任务中，当目标的空间位置被先前的刺激（有效线索）正确预测时，正常人类的反应比位置被错误预测时（无效线索）更快。假设线索会将注意力转移到其位置，从而促进或阻碍反应潜伏期。如果目标之前有有效线索，那么顶叶受损个体对病变同侧或对侧目标的反应时间会有所减慢。当线索刚出现在未受影响（同侧）视野中时，这些患者对病变对侧视野中的目标反应极其缓慢。此外，当整个视野有微弱、漫射光照在目标之前时，这些个体对任何一个视野中的目标反应都特别缓慢。额叶病变患者一般反应时间非常慢，并且与颞叶病变患者一样，在病变对侧视野中的目标在所有情况下反应都很慢。这些模式可能与注意力缺陷无关。对于顶叶病变患者，这些研究表明在线索反应时间任务中存在进一步的缺陷，提示视觉注意力异常。由于脑损伤的不同部位会产生不同的反应模式，像这样的测试可能具有分析和诊断价值。
