Baycrest Health Sciences, Rotman Research Institute, University of Toronto, Canada.
Baycrest Health Sciences, Rotman Research Institute, University of Toronto, Canada.
Neuropsychologia. 2020 Sep;146:107565. doi: 10.1016/j.neuropsychologia.2020.107565. Epub 2020 Jul 21.
Optimal performance in many tasks requires minimizing the impact of both visual distractors in the environment and distracting internal thoughts (i.e., mind-wandering). Prior research has indicated that older adults are disproportionately affected by the presence of visual distractors compared to young adults, but are not excessively affected by distracting thoughts. Yet an explanation for these dissociable effects remains elusive. In the current study, we assessed age-related differences in event-related potentials and neural variability associated with internal distraction and visual distractors in a go/no-go task. Compared to young adults, older adults showed an increased visual distraction cost in mean reaction time (RT) and RT variability but a reduction in internal distraction frequency and a reduced internal distraction cost on go accuracy and RT variability. Visual distraction and internal distraction were associated with opposite patterns of behavioral and neural effects. Behaviorally, across age groups, internal distraction was associated with more no-go errors whereas visual distraction was associated with reduced no-go errors. Across groups, internal distraction was associated with decreased P3 amplitude, whereas visual distraction was associated with increased P3 amplitude. In addition, internal distraction was associated with an increase in neural variability (more so in young versus older adults), while visual distraction was associated with a reduction in variability in young adults only. We suggest that the opposing effects of the two distractor types on behavioral and neural measures occur because visual distraction is associated with increased attentional resources devoted to the task to overcome visual interference whereas internal distraction is associated with decreased attentional resources devoted to the task. Moreover, older adults exhibited reduced flexibility of neural variability as a function of both distractor types, which may correspond to a diminished ability to up-regulate attention in the face of visual distraction and a diminished shift in attention away from the task during internal distraction.
在许多任务中表现最佳需要将环境中的视觉干扰和分心的内部想法（即思维漫游）的影响最小化。先前的研究表明，与年轻人相比，老年人受到视觉干扰的影响不成比例，但不会受到分心想法的过度影响。然而，对于这些可分离的影响仍然难以解释。在当前的研究中，我们评估了与内部分心和在 Go/No-Go 任务中的视觉分心相关的与年龄相关的事件相关电位和神经变异性差异。与年轻人相比，老年人在平均反应时间 (RT) 和 RT 变异性方面表现出增加的视觉干扰成本，但在 Go 准确性和 RT 变异性方面表现出内部干扰频率降低和内部干扰成本降低。视觉干扰和内部干扰与行为和神经效应的相反模式相关。行为上，在所有年龄组中，内部干扰与更多的不能反应错误相关，而视觉干扰与减少的不能反应错误相关。在所有组中，内部干扰与 P3 振幅降低相关，而视觉干扰与 P3 振幅增加相关。此外，内部干扰与神经变异性增加（年轻人比老年人更明显）相关，而视觉干扰与年轻人的变异性降低相关。我们认为，两种干扰类型对行为和神经测量的相反影响是因为视觉干扰与为克服视觉干扰而分配给任务的注意力资源增加有关，而内部干扰与分配给任务的注意力资源减少有关。此外，老年人表现出神经变异性的灵活性降低，这是两种干扰类型的功能，这可能对应于在面对视觉干扰时注意力调节能力的降低，以及在内部干扰期间注意力从任务转移的能力降低。
