School of Humanities and Social Sciences, Jacobs University Bremen, Germany.
Cortex. 2010 Oct;46(9):1149-64. doi: 10.1016/j.cortex.2009.07.013. Epub 2009 Aug 3.
Patients with left neglect are particularly slow to respond to visual targets on their left when attention is first engaged to their right. This deficit is known as the disengage deficit (DD). Studies investigating the DD typically employ nonpredictive peripheral onset cues to measure involuntary orienting and predictive central arrow cues to measure voluntary orienting. A DD has been observed with both cues, suggesting that a DD occurs for involuntary and for voluntary orienting. Recent evidence questions this conclusion because nonpredictive central arrow cues trigger involuntary orienting. This implies that predictive central arrows also involve involuntary orienting and do not measure only voluntary attention. This new knowledge suggests a new conceptualization of the DD. While it is undisputed that a DD occurs when attention is shifted involuntarily, it is uncertain whether a DD is produced by voluntary orienting because most previous cuing studies of the DD have involved shifts of involuntary attention. To address this critical question, we tested neglect and control patients with nonpredictive and predictive peripheral onset cues (Experiment 1), nonpredictive and predictive central arrow cues (Experiment 2), and predictive central number cues (Experiment 3). The experiments provide three lines of converging evidence that voluntary orienting does not contribute to a DD. First, the DD was the same whether attention was engaged involuntarily by nonpredictive peripheral cues or engaged involuntarily and voluntarily by predictive peripheral cues (Experiment 1), indicating that voluntary orienting does not modulate the DD. Second, the DD was the same whether attention was engaged involuntarily by nonpredictive central arrow cues or engaged involuntarily and voluntarily by predictive central arrow cues (Experiment 2), replicating the finding of Experiment 1 with very different cues. Third, the DD was not present when attention was only engaged voluntarily by central predictive number cues (Experiment 3).
患者左侧忽视症在注意力最初集中于右侧时，对左侧视觉目标的反应特别缓慢。这种缺陷被称为脱离缺陷（DD）。研究 DD 的典型方法是使用非预测性外周起始线索来测量非自愿定向，以及使用预测性中央箭头线索来测量自愿定向。这两种线索都观察到了 DD，这表明 DD 不仅发生在非自愿定向，也发生在自愿定向。最近的证据对此结论提出了质疑，因为非预测性中央箭头线索会引发非自愿定向。这意味着预测性中央箭头也涉及非自愿定向，而不仅仅测量自愿注意力。这一新的知识对 DD 提出了新的概念化。虽然当注意力非自愿转移时会出现 DD 这一点是毋庸置疑的，但还不确定 DD 是否是由自愿定向引起的，因为之前关于 DD 的大多数线索研究都涉及非自愿注意力的转移。为了解决这个关键问题，我们使用非预测性和预测性外周起始线索（实验 1）、非预测性和预测性中央箭头线索（实验 2）以及预测性中央数字线索（实验 3）测试了忽视症和对照组患者。这些实验提供了三条相互一致的证据，表明自愿定向不会导致 DD。首先，无论注意力是通过非预测性外周线索非自愿地还是通过预测性外周线索非自愿地和自愿地参与，DD 都是相同的（实验 1），表明自愿定向不会调节 DD。其次，无论注意力是通过非预测性中央箭头线索非自愿地还是通过预测性中央箭头线索非自愿地和自愿地参与，DD 都是相同的（实验 2），这与实验 1 的发现非常不同，但结果一致。第三，当注意力仅通过中央预测性数字线索自愿地参与时，DD 不存在（实验 3）。
