Willamette University, Department of Psychology, 900 State Street, Salem, OR 97301, United States.
University of Pittsburgh Medical Center, 121 Meyran Avenue, Pittsburgh, PA 15213, United States.
Int J Psychophysiol. 2015 Feb;95(2):156-66. doi: 10.1016/j.ijpsycho.2014.06.017. Epub 2014 Jul 6.
Previous neuroimaging studies indicate that lower socio-economic status (SES) is associated with reduced effects of selective attention on auditory processing. Here, we investigated whether lower SES is also associated with differences in a stimulus-driven aspect of auditory processing: the neural refractory period, or reduced amplitude response at faster rates of stimulus presentation. Thirty-two children aged 3 to 8 years participated, and were divided into two SES groups based on maternal education. Event-related brain potentials were recorded to probe stimuli presented at interstimulus intervals (ISIs) of 200, 500, or 1000 ms. These probes were superimposed on story narratives when attended and ignored, permitting a simultaneous experimental manipulation of selective attention. Results indicated that group differences in refractory periods differed as a function of attention condition. Children from higher SES backgrounds showed full neural recovery by 500 ms for attended stimuli, but required at least 1000 ms for unattended stimuli. In contrast, children from lower SES backgrounds showed similar refractory effects to attended and unattended stimuli, with full neural recovery by 500 ms. Thus, in higher SES children only, one functional consequence of selective attention is attenuation of the response to unattended stimuli, particularly at rapid ISIs, altering basic properties of the auditory refractory period. Together, these data indicate that differences in selective attention impact basic aspects of auditory processing in children from lower SES backgrounds.
先前的神经影像学研究表明，较低的社会经济地位（SES）与选择性注意对听觉处理的影响降低有关。在这里，我们研究了较低的 SES 是否也与听觉处理的刺激驱动方面的差异有关：神经不应期，即在更快的刺激呈现速率下，振幅反应降低。32 名 3 至 8 岁的儿童参与了研究，并根据母亲的教育程度分为两个 SES 组。记录事件相关脑电位以探测在刺激间间隔（ISI）为 200、500 或 1000 毫秒的刺激。当注意和忽略这些探针时，它们会叠加在故事叙述上，从而可以同时对选择性注意进行实验操作。结果表明，不应期的组间差异随注意条件而变化。来自较高 SES 背景的儿童在注意刺激时，500 毫秒即可完全恢复神经，但在未注意刺激时则需要至少 1000 毫秒。相比之下，来自较低 SES 背景的儿童对注意和未注意的刺激表现出相似的不应期效应，在 500 毫秒时即可完全恢复神经。因此，只有在 SES 较高的儿童中，选择性注意的一个功能后果是减弱对未注意刺激的反应，特别是在快速 ISI 时，改变了听觉不应期的基本特性。这些数据表明，选择性注意的差异会影响 SES 较低的儿童的基本听觉处理。
