Rotman Research Institute, Baycrest Hospital & Department of Psychology, University of Toronto, Toronto, Canada.
Medical Research Council Institute of Hearing Research, The University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
Sci Rep. 2017 May 9;7(1):1595. doi: 10.1038/s41598-017-00811-7.
In everyday situations auditory selective attention requires listeners to suppress task-irrelevant stimuli and to resolve conflicting information in order to make appropriate goal-directed decisions. Traditionally, these two processes (i.e. distractor suppression and conflict resolution) have been studied separately. In the present study we measured neuroelectric activity while participants performed a new paradigm in which both processes are quantified. In separate block of trials, participants indicate whether two sequential tones share the same pitch or location depending on the block's instruction. For the distraction measure, a positive component peaking at ~250 ms was found - a distraction positivity. Brain electrical source analysis of this component suggests different generators when listeners attended to frequency and location, with the distraction by location more posterior than the distraction by frequency, providing support for the dual-pathway theory. For the conflict resolution measure, a negative frontocentral component (270-450 ms) was found, which showed similarities with that of prior studies on auditory and visual conflict resolution tasks. The timing and distribution are consistent with two distinct neural processes with suppression of task-irrelevant information occurring before conflict resolution. This new paradigm may prove useful in clinical populations to assess impairments in filtering out task-irrelevant information and/or resolving conflicting information.
在日常情况下，听觉选择性注意要求听众抑制与任务无关的刺激，并解决冲突信息，以便做出适当的目标导向决策。传统上，这两个过程（即干扰抑制和冲突解决）是分开研究的。在本研究中，我们在参与者执行一个新的范式时测量了神经电活动，在这个范式中可以同时量化这两个过程。在单独的试验块中，参与者根据块的指令来判断两个连续的音调是否具有相同的音高或位置。对于分心测量，发现了一个在~250ms 左右达到峰值的正成分——分心正波。对该成分的脑电源分析表明，当听众关注频率和位置时，存在不同的产生器，位置分心比频率分心更靠后，这为双通道理论提供了支持。对于冲突解决测量，发现了一个负的额中央成分（270-450ms），它与先前关于听觉和视觉冲突解决任务的研究相似。其时间和分布与抑制与任务无关的信息发生在冲突解决之前的两个不同的神经过程一致。这种新的范式可能在临床人群中证明有用，可用于评估过滤掉与任务无关的信息和/或解决冲突信息的障碍。
