Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Füchsleinstraβe 15, 97080 Würzburg, Germany.
BMC Neurosci. 2013 Oct 1;14:107. doi: 10.1186/1471-2202-14-107.
The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated.
Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses.
Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.
先前已经证明了任务相关性对早期视觉处理事件相关电位幅度的影响。然而，研究设计差异很大，无法同时研究分心程度和任务相关性如何影响处理变化。在我们的研究中，我们结合了以前任务的不同特征。我们使用了一种修改后的 1 背任务，其中任务相关和任务不相关的刺激交替呈现。任务不相关的刺激可以与任务相关的刺激来自同一类别，也可以来自不同的类别，从而产生高和低分散注意力的任务不相关刺激。此外，该范式还包括被动观看条件。因此，我们的范式使我们能够比较任务相关刺激、具有不同分心程度的任务不相关刺激以及被动观看刺激的处理。从二十名参与者那里收集了 EEG 数据，并分析了平均 P100 和 N170 幅度。此外，还研究了刺激处理与注意力缺陷多动障碍（ADHD）症状之间的潜在联系。
我们的结果表明，任务相关性会调节峰值 N170 幅度。与高分散注意力的任务不相关或被动观看的刺激相比，任务相关刺激的 N170 幅度明显更高。此外，与高分散注意力的任务不相关刺激相比，低分散注意力的任务不相关刺激的幅度明显更高。被动观看的刺激的 N170 幅度与任何一种任务不相关刺激都没有显著差异。多动和冲动症状较多的参与者在所有任务条件下的 N170 幅度均降低。在行为水平上，较低的 N170 增强效率与错误警报反应显著相关。
我们的结果表明，任务相关刺激的处理得到了增强。与 P100 幅度不同，N170 幅度受到增强的强烈影响，并且增强效率似乎具有直接的行为后果。这些发现对影响选择性注意的临床障碍模型，特别是 ADHD 具有潜在的意义。
