Clinique de Reeducation, HUG, Geneve, Switzerland.
Cogn Neuropsychol. 2005 Feb;22(1):111-27. doi: 10.1080/02643290342000654.
Repetition blindness (RB) is the failure to report a visual stimulus presented shortly after a first occurrence of the same stimulus (Kanwisher, 1987). A similar phenomenon is that visual extinction, the failure to identify a contralesional stimulus presented simultaneously with an ipsilesional stimulus, increases with increasing similarity between the contralesional and ipsilesional stimulus (Baylis, Driver, & Rafal, 1993). We report a patient who, after a right parietal stroke, presented increased extinction for letters in repeated (e.g., A + A) than in unrepeated (e.g., T + U) displays. Increased extinction due to RB was observed in all experimental conditions probing item identification and varied between 5.4% and 40.6% across conditions. RB was unaffected by temporal modulation of the display, but was significantly reduced when stimuli grouped by a surrounding contour. Identification of contralesional repeated and unrepeated letters could be enhanced by auditory cues presented prior to the visual display. These results suggest that perceptual processing of extinguished stimuli that are similar to the stimulus presented on the preserved side is relatively unimpaired, but that the patient fails to ascribe to the stimulus a separate identity, supporting the distinction between type recognition and token individuation (Kanwisher, 1987). The extinction patterns for similar and dissimilar stimuli indicate that competition for attentional selection does not only occur at low (perceptual) levels, but also at higher processing levels, suggesting the presence of attentional competition on different levels of analysis.
重复盲（RB）是指未能报告在同一刺激首次出现后不久呈现的视觉刺激（Kanwisher，1987）。类似的现象是视觉失认，即当对侧刺激与同侧刺激同时呈现时，无法识别对侧刺激，这种现象随着对侧和同侧刺激之间的相似性增加而增加（Baylis、Driver 和 Rafal，1993）。我们报告了一名患者，在右顶叶中风后，在重复呈现（例如，A+A）的字母中，比在非重复呈现（例如，T+U）的字母中，失认增加。在所有探测项目识别的实验条件下都观察到由于 RB 引起的失认增加，并且在不同条件下的变化范围为 5.4%至 40.6%。RB 不受显示时间调制的影响，但当刺激按周围轮廓分组时，RB 显著减少。通过在视觉显示之前呈现听觉提示，可以增强对侧重复和非重复字母的识别。这些结果表明，对与保留侧呈现的刺激相似的失认刺激的感知处理相对未受损，但患者未能将刺激赋予单独的身份，支持了类型识别和令牌个体化之间的区别（Kanwisher，1987）。相似和不同刺激的失认模式表明，注意力选择的竞争不仅发生在低（感知）水平，而且还发生在更高的处理水平，这表明在不同的分析水平上存在注意力竞争。
