Hearing Research Center, Biomedical Engineering, Boston, MA 02215, USA.
J Assoc Res Otolaryngol. 2012 Feb;13(1):119-29. doi: 10.1007/s10162-011-0299-7. Epub 2011 Nov 29.
Past studies have explored the relative strengths of auditory features in a selective attention task by pitting features against one another and asking listeners to report the words perceived in a given sentence. While these studies show that the continuity of competing features affects streaming, they did not address whether the influence of specific features is modulated by volitionally directed attention. Here, we explored whether the continuity of a task-irrelevant feature affects the ability to selectively report one of two competing speech streams when attention is specifically directed to a different feature. Sequences of simultaneous pairs of spoken digits were presented in which exactly one digit of each pair matched a primer phrase in pitch and exactly one digit of each pair matched the primer location. Within a trial, location and pitch were randomly paired; they either were consistent with each other from digit to digit or were switched (e.g., the sequence from the primer's location changed pitch across digits). In otherwise identical blocks, listeners were instructed to report digits matching the primer either in location or in pitch. Listeners were told to ignore the irrelevant feature, if possible, in order to perform well. Listener responses depended on task instructions, proving that top-down attention alters how a subject performs the task. Performance improved when the separation of the target and masker in the task-relevant feature increased. Importantly, the values of the task-irrelevant feature also influenced performance in some cases. Specifically, when instructed to attend location, listeners performed worse as the separation between target and masker pitch increased, especially when the spatial separation between digits was small. These results indicate that task-relevant and task-irrelevant features are perceptually bound together: continuity of task-irrelevant features influences selective attention in an automatic, obligatory manner, consistent with the idea that auditory attention operates on objects.
过去的研究通过将特征相互对立，并要求听众报告给定句子中感知到的单词，来探索在选择性注意任务中听觉特征的相对强度。虽然这些研究表明竞争特征的连续性会影响流，但它们并没有解决特定特征的影响是否受到意志指向注意力的调节。在这里，我们探讨了当注意力被专门引导到不同特征时，一个与任务无关的特征的连续性是否会影响选择性报告两个竞争语音流之一的能力。同时呈现了同时对说话数字的对序列，其中每对的一个数字与音高的启动短语匹配，每对的一个数字与启动位置匹配。在一次试验中，位置和音高随机配对；它们要么从一个数字到另一个数字都相互一致，要么相互切换（例如，从启动器位置的序列在数字之间改变音高）。在其他完全相同的块中，听众被指示根据位置或音高报告与启动器匹配的数字。听众被告知如果可能的话忽略不相关的特征，以便表现良好。听众的反应取决于任务指令，证明自上而下的注意力改变了受试者执行任务的方式。当与任务相关的特征中的目标和掩蔽之间的分离增加时，性能会提高。重要的是，在某些情况下，不相关特征的值也会影响性能。具体来说，当被指示注意位置时，随着目标和掩蔽音高之间的分离增加，听众的表现会变差，尤其是当数字之间的空间分离较小时。这些结果表明，任务相关和任务无关的特征在感知上是绑定在一起的：任务无关特征的连续性以自动的、强制性的方式影响选择性注意，这与听觉注意力作用于对象的观点一致。
