Volosin Márta, Horváth János
Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; Institute of Psychology, University of Szeged, Egyetem utca 2, H-6722 Szeged, Hungary.
Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, H-1117 Budapest, Hungary; Institute of Psychology, Károli Gáspár University of the Reformed Church in Hungary, Bécsi út 324, H-1037 Budapest, Hungary.
Brain Res. 2020 Jan 15;1727:146565. doi: 10.1016/j.brainres.2019.146565. Epub 2019 Nov 22.
Keeping task-relevant sensory events in the focus of attention while ignoring irrelevant ones is crucial for optimizing task behavior. This attention-distraction balance might change with the perceptual demands of the ongoing task: while easy tasks might be performed with low attentional effort, difficult ones require enhanced attention. The goal of the present study was to investigate how task difficulty affected allocation of attention and distractibility in an auditory distraction paradigm. Participants performed a tone duration discrimination task in which tones were rarely, occasionally presented at a rare pitch (distracters), and task difficulty was manipulated by the duration difference between short and long tones. Short tones were consistently 200 ms long, while long tone duration was 400 ms in the easy, and 260 ms in the difficult condition. Behavioral results and deviant-minus-standard event-related potential (ERP) waveforms suggested similar magnitudes of distraction in both conditions. ERPs without such a subtraction showed that tone onsets were preceded by a negative-going trend, suggesting that participants prepared for tone onsets. In the difficult condition, N1 amplitudes to tone onsets were enhanced, indicating that participants invested more attentional resources. Increased difficulty also slowed down tone offset processing as reflected by significantly delayed offset-related P1 and N1/N2 waveforms. These results suggest that although task difficulty compels participants to attend the tones more strongly, this does not have significant impact on distraction-related processing.
在关注与任务相关的感觉事件的同时忽略无关事件，对于优化任务行为至关重要。这种注意力-干扰平衡可能会随着当前任务的感知需求而变化：简单任务可能只需较少的注意力就能完成，而困难任务则需要更强的注意力。本研究的目的是在听觉干扰范式中研究任务难度如何影响注意力分配和易受干扰性。参与者执行了一个音调持续时间辨别任务，其中音调很少、偶尔以罕见音高呈现（干扰项），任务难度通过短音和长音之间的持续时间差异来操纵。短音始终为200毫秒长，而在简单条件下长音持续时间为400毫秒，在困难条件下为260毫秒。行为结果和偏离减去标准的事件相关电位（ERP）波形表明两种条件下的干扰程度相似。未经这种减法处理的ERP显示，音调开始之前有一个负向趋势，表明参与者为音调开始做了准备。在困难条件下，对音调开始的N1波幅增强，表明参与者投入了更多的注意力资源。难度增加也减缓了音调结束处理，这表现为与结束相关的P1和N1/N2波形明显延迟。这些结果表明，尽管任务难度迫使参与者更强烈地关注音调，但这对与干扰相关的处理没有显著影响。
