Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
Neurobiol Aging. 2013 Mar;34(3):973-85. doi: 10.1016/j.neurobiolaging.2012.08.002. Epub 2012 Aug 24.
Attentional decline plays a major role in cognitive changes with aging. However, which specific aspects of attention contribute to this decline is as yet little understood. To identify the contributions of various potential sources of age decrements in visual search, we combined response time measures with lateralized event-related potentials of younger and older adults performing a compound-search task, in which the target-defining dimension of a pop-out target (color/shape) and the response-critical target feature (vertical/horizontal stripes) varied independently across trials. Slower responses in older participants were associated with age differences in all analyzed event-related potentials from perception to response, indicating that behavioral slowing originates from multiple stages within the information-processing stream. Furthermore, analyses of carry-over effects from one trial to the next revealed repetition facilitation of the target-defining dimension and of the motor response-originating from preattentive perceptual and motor execution stages, respectively-to be independent of age. Critically, we demonstrated specific age deficits on intermediate processing stages when intertrial changes required more executively controlled processes, such as flexible stimulus-response (re-)mapping across trials.
注意力下降在衰老引起的认知变化中起着重要作用。然而，哪些特定的注意力方面有助于这种下降目前还不太清楚。为了确定视觉搜索中各种潜在来源的年龄衰退的贡献，我们结合了年轻和年长成年人执行复合搜索任务的反应时测量和偏侧化事件相关电位，其中弹出目标（颜色/形状）的目标定义维度和响应关键目标特征（垂直/水平条纹）在试验之间独立变化。年长参与者的反应较慢与从感知到反应的所有分析事件相关电位中的年龄差异有关，这表明行为减速源自信息处理流中的多个阶段。此外，对下一个试验的余波效应的分析表明，目标定义维度和运动反应的重复促进作用分别来自于前注意知觉和运动执行阶段，与年龄无关。至关重要的是，当试验间变化需要更多执行控制过程时，例如在试验间灵活的刺激-反应（重新）映射，我们在中间处理阶段表现出特定的年龄缺陷。
