Làdavas E, Petronio A, Umiltà C
Dipartimento di Psicologia, University of Bologna, Italy.
Cortex. 1990 Sep;26(3):307-17. doi: 10.1016/s0010-9452(13)80083-4.
Patients with left hemispatial neglect after right hemisphere lesions and control patients with right hemisphere lesions were presented in the ipsilesional (i.e., intact) visual field with stimuli that could occupy left-right relative positions. The patients were required to discriminate between target stimuli and distractors by emitting go/no-go responses. Reaction times (RTs) and measures of sensitivity (d') and response bias (beta) were obtained. The within-subjects comparisons showed that neglect patients were faster in the right than the left relative position, whereas control patients were faster in the left than the right relative position. The between-subjects comparisons showed that neglect patients were faster than control patients in the right relative position but slower in the left relative position. These effects were due to changes in processing efficiency, as attested by the fact that the differences in response speed were accompanied by congruent differences in sensitivity, whereas no differences in response bias were found. The results were interpreted by assuming that neglect patients focus attention on the right relative position and, therefore, have a small attentional focus concentrated on that position. By contrast, control patients, like normal subjects, would distribute attention between the two possible stimulus positions and, therefore, allocate attention to a larger portion of the visual field.
患有右侧半球损伤后出现左侧半空间忽视的患者以及患有右侧半球损伤的对照患者，在同侧（即完好的）视野中呈现可占据左右相对位置的刺激。要求患者通过发出“执行/不执行”反应来区分目标刺激和干扰物。获得了反应时间（RTs）、灵敏度测量值（d'）和反应偏差（beta）。受试者内比较表明，忽视患者在右侧相对位置比在左侧相对位置反应更快，而对照患者在左侧相对位置比在右侧相对位置反应更快。受试者间比较表明，忽视患者在右侧相对位置比对照患者反应更快，但在左侧相对位置比对照患者反应更慢。这些效应是由于处理效率的变化，这一点得到了如下事实的证明：反应速度的差异伴随着灵敏度的相应差异，而未发现反应偏差存在差异。通过假设忽视患者将注意力集中在右侧相对位置，因此有一个小的注意力焦点集中在该位置，对结果进行了解释。相比之下，对照患者与正常受试者一样，会在两个可能的刺激位置之间分配注意力，因此会将注意力分配到更大的视野范围。
