Department of Psychology, Umeå University, Umeå, Sweden.
J Exp Psychol Learn Mem Cogn. 2012 Sep;38(5):1461-8. doi: 10.1037/a0028149. Epub 2012 May 7.
Sounds deviating from an otherwise repeated stream of task-irrelevant auditory stimuli (deviant sounds among standard sounds) are known to capture attention and impact negatively on ongoing behavioral performance (behavioral oddball distraction). Traditional views consider such distraction as the ineluctable consequence of the deviant sounds' low probability of occurrence relative to that of the standard. Contrary to this contention, recent evidence demonstrates that distraction by deviant sounds is not obligatory and occurs only when sounds (standards and deviants), though to be ignored, act as useful warning cues by providing information as to whether and when a target stimulus is to be presented (Parmentier, Elsley, & Ljungberg, 2010). The present study aimed to extend this finding by disentangling the roles of event information (target's probability of occurrence) and temporal information (target's time of occurrence). Comparing performance in a cross-modal oddball task where standard and deviant sounds provided temporal information, event information, both, or none, we found that distraction by deviant sounds emerged when sounds conveyed event information. These results suggest that unexpected changes in a stream of sounds yield behavioral distraction to the extent that standards and deviants carry relevant goal-directed information, specifically, the likelihood of occurrence of an upcoming target.
与任务无关的听觉刺激（标准声音中的变调声音）偏离原本重复的声音流时，已知会吸引注意力并对正在进行的行为表现产生负面影响（行为异常分心）。传统观点认为，这种分心是由于变调声音的出现概率相对标准声音较低所不可避免的结果。与这种观点相反，最近的证据表明，变调声音引起的分心并非强制性的，只有在声音（标准声音和变调声音）虽然要被忽略，但作为有用的警告线索时，才会发生分心，这些线索提供了关于目标刺激何时呈现的信息（Parmentier、Elsley 和 Ljungberg，2010）。本研究旨在通过区分事件信息（目标出现的概率）和时间信息（目标出现的时间）来扩展这一发现。在一项跨模态异常声音任务中比较表现，其中标准声音和变调声音提供了时间信息、事件信息、两者或都不提供，我们发现，当声音传达事件信息时，变调声音会引起分心。这些结果表明，声音流中出现意外变化会导致行为分心，程度取决于标准声音和变调声音是否携带相关的目标导向信息，具体来说，就是即将出现的目标的出现可能性。
