Interdisciplinary Neuroscience Program, Bilkent University, Ankara, Turkey; Department of Psychology, Justus Liebig University in Giessen, Giessen, Germany.
Interdisciplinary Neuroscience Program, Bilkent University, Ankara, Turkey; Department of Psychology, Bilkent University, Ankara, Turkey; Aysel Sabuncu Brain Research Center and National Magnetic Resonance Imaging Center, Bilkent University, Ankara, Turkey.
Vision Res. 2024 Jan;214:108328. doi: 10.1016/j.visres.2023.108328. Epub 2023 Nov 4.
Considering its importance for one's survival and social significance, biological motion (BM) perception is assumed to occur automatically. Previous behavioral results showed that task-irrelevant BM in the periphery interfered with task performance at the fovea. Under selective attention, BM perception is supported by a network of regions including the occipito-temporal (OTC), parietal, and premotor cortices. Retinotopy studies that use BM stimulus showed distinct maps for its processing under and away from selective attention. Based on these findings, we investigated how bottom-up perception of BM would be processed in the human brain under attentional load when it was shown away from the focus of attention as a task-irrelevant stimulus. Participants (N = 31) underwent an fMRI study in which they performed an attentionally demanding visual detection task at the fovea while intact or scrambled point light displays of BM were shown at the periphery. Our results showed the main effect of attentional load in fronto-parietal regions and both univariate activity maps and multivariate pattern analysis results support the attentional load modulation on the task-irrelevant peripheral stimuli. However, this effect was not specific to intact BM stimuli and was generalized to motion stimuli as evidenced by the motion-sensitive OTC involvement during the presence of dynamic stimuli in the periphery. These results confirm and extend previous work by showing that task-irrelevant distractors can be processed by stimulus-specific regions when there are enough attentional resources available. We discussed the implications of these results for future studies.
考虑到生物运动（BM）感知对于个体的生存和社交意义的重要性，人们假设这种感知是自动发生的。先前的行为研究结果表明，周边的与任务无关的 BM 会干扰中央凹的任务表现。在选择性注意下，BM 感知得到包括枕颞（OTC）、顶叶和运动前皮质在内的区域网络的支持。使用 BM 刺激的视网膜研究表明，在选择性注意下和远离选择性注意时，其处理方式存在明显差异。基于这些发现，我们研究了当作为无关任务刺激的 BM 在远离注意力焦点的情况下呈现时，在注意力负荷下，人类大脑会如何处理其自下而上的感知。参与者（N=31）接受了 fMRI 研究，他们在中央凹进行了一项注意力要求高的视觉检测任务，同时在周边呈现完整或打乱的点光 BM 显示。我们的结果显示，在额顶叶区域存在注意力负荷的主要影响，并且单变量活动图和多元模式分析结果均支持对无关外周刺激的注意力负荷调节。然而，这种影响并非特定于完整的 BM 刺激，而是推广到运动刺激，这一点可通过在周边呈现动态刺激时 OTC 对运动刺激的敏感性得到证明。这些结果证实并扩展了先前的工作，表明当有足够的注意力资源时，无关的干扰物可以通过刺激特异性区域进行处理。我们讨论了这些结果对未来研究的意义。
