Getzmann Stephan, Falkenstein Michael, Wascher Edmund
Leibniz Research Centre for Working Environment and Human Factors at the Technical University of Dortmund (IfADo), Ardeystraße 67, D-44139 Dortmund, Germany.
Leibniz Research Centre for Working Environment and Human Factors at the Technical University of Dortmund (IfADo), Ardeystraße 67, D-44139 Dortmund, Germany.
Behav Brain Res. 2015 Feb 1;278:435-45. doi: 10.1016/j.bbr.2014.10.026. Epub 2014 Oct 29.
The ability to understand speech under adverse listening conditions deteriorates with age. In addition to genuine hearing deficits, age-related declines in attentional and inhibitory control are assumed to contribute to these difficulties. Here, the impact of task-irrelevant distractors on speech perception was studied in 28 younger and 24 older participants in a simulated "cocktail party" scenario. In a two-alternative forced-choice word discrimination task, the participants responded to a rapid succession of short speech stimuli ("on" and "off") that was presented at a frequent standard location or at a rare deviant location in silence or with a concurrent distractor speaker. Behavioral responses and event-related potentials (mismatch negativity MMN, P3a, and reorienting negativity RON) were analyzed to study the interplay of distraction, orientation, and refocusing in the presence of changes in target location. While shifts in target location decreased performance of both age groups, this effect was more pronounced in the older group. Especially in the distractor condition, the electrophysiological measures indicated a delayed attention capture and a delayed re-focussing of attention toward the task-relevant stimulus feature in the older group, relative to the young group. In sum, the results suggest that a delay in the attention switching mechanism contribute to the age-related difficulties in speech perception in dynamic listening situations with multiple speakers.
在不利的听觉条件下理解言语的能力会随着年龄的增长而下降。除了真正的听力缺陷外，与年龄相关的注意力和抑制控制能力下降也被认为是导致这些困难的原因。在此，在模拟的“鸡尾酒会”场景中，对28名年轻参与者和24名年长参与者研究了与任务无关的干扰因素对言语感知的影响。在一个二选一的强制选择单词辨别任务中，参与者对一系列快速呈现的短语音刺激（“开”和“关”）做出反应，这些刺激在一个常见的标准位置或一个罕见的异常位置呈现，呈现时处于安静状态或同时伴有一个干扰说话者。分析行为反应和事件相关电位（失配负波MMN、P3a和重新定向负波RON），以研究在目标位置发生变化时干扰、定向和重新聚焦之间的相互作用。虽然目标位置的变化降低了两个年龄组的表现，但这种影响在年长组中更为明显。特别是在有干扰因素的情况下，电生理测量结果表明，与年轻组相比，年长组在注意力捕捉和将注意力重新聚焦到与任务相关的刺激特征方面存在延迟。总之，研究结果表明，注意力转换机制的延迟导致了在有多个说话者的动态听力情况下与年龄相关的言语感知困难。
