Gösta Ekmans Laboratorium, Department of Psychology, Stockholm University, Stockholm, Sweden.
Gösta Ekmans Laboratorium, Department of Psychology, Stockholm University, Stockholm, Sweden.
Physiol Behav. 2021 Jan 1;228:113240. doi: 10.1016/j.physbeh.2020.113240. Epub 2020 Nov 12.
Ignoring background sounds while focusing on a visual task is a necessary ability in everyday life. If attentional resources are shared between modalities, processing of task-irrelevant auditory information should become attenuated when attentional capacity is expended by visual demands. According to the early-filter model, top-down attenuation of auditory responses is possible at various stages of the auditory pathway through multiple recurrent loops. Furthermore, the adaptive filtering model of selective attention suggests that filtering occurs early when concurrent visual tasks are demanding (e.g., high load) and late when tasks are easy (e.g., low load). To test these models, this study examined the effects of three levels of visual load on auditory steady-state responses (ASSRs) at three modulation frequencies. Subjects performed a visual task with no, low, and high visual load while ignoring task-irrelevant sounds. The auditory stimuli were 500-Hz tones amplitude-modulated at 20, 40, or 80 Hz to target different processing stages of the auditory pathway. Results from bayesian analyses suggest that ASSRs are unaffected by visual load. These findings imply that attentional resources are modality specific and that the attentional filter of auditory processing does not vary with visual task demands.
在专注于视觉任务的同时忽略背景声音是日常生活中必备的能力。如果注意资源在模态之间共享，那么当视觉需求消耗注意力容量时，对任务不相关听觉信息的处理应该会减弱。根据早期过滤模型，通过多个递归回路，在听觉通路的各个阶段都有可能对听觉反应进行自上而下的衰减。此外，选择性注意的自适应滤波模型表明，当同时进行的视觉任务要求较高（例如高负载）时，过滤会较早发生，而当任务较容易（例如低负载）时，过滤会较晚发生。为了检验这些模型，本研究在三种调制频率下，考察了三种视觉负荷水平对听觉稳态反应（ASSR）的影响。受试者在忽略任务不相关声音的情况下，执行无、低和高视觉负荷的视觉任务。听觉刺激是 500Hz 音调，以 20、40 或 80Hz 的幅度调制，以针对听觉通路的不同处理阶段。贝叶斯分析的结果表明，ASSR 不受视觉负荷的影响。这些发现表明，注意力资源是特定于模态的，听觉处理的注意过滤器不会随视觉任务需求而变化。
