Mertens Meret, Binkofski Ferdinand, Leitão Bruno, Grii Bichr, Rodriguez-Raecke Rea, Schüppen André, Pellicano Antonello, Lorentz Lukas, Sijben Rik
Division of Clinical Cognitive Sciences, Department of Neurology, University Hospital RWTH Aachen, Pauwelsstraße 17, Aachen 52074, Germany.
Division of Clinical Cognitive Sciences, Department of Neurology, University Hospital RWTH Aachen, Pauwelsstraße 17, Aachen 52074, Germany; Institute for Neuroscience and Medicine (INM-4), Research Center Jülich GmbH, Jülich, Germany; JARA-BRAIN, Jülich-Aachen Research Alliance, Jülich GmbH, Jülich, Germany.
Neuroimage. 2025 Aug 15;317:121325. doi: 10.1016/j.neuroimage.2025.121325. Epub 2025 Jun 13.
The brain processes objects in reachable peripersonal space and non-reachable extrapersonal space in different neural networks. In contrast to extrapersonal space, spatial processing in peripersonal space is linked to the activation of affordances in dorsal visual pathways. However, the literature on how object characteristics like size, graspability and stereoscopic presentation influence object processing in virtual environments is still unclear. In the current study, 44 healthy participants performed a visual discrimination task involving graspable objects presented in peripersonal space and extrapersonal space. The paradigm was presented via MRI-compatible goggles during fMRI scanning. The four sessions alternated between monoscopic and stereoscopic presentations and stimuli varied within the sessions in apparent distance, size, and orientation. To validate the effect of distance, the pixel size of objects was also controlled. Stereoscopic presentation enhanced dorsal stream activation, particularly in V5/MT, lateral occipital cortex and the posterior intraparietal sulcus, associated with depth processing, suggesting increased peripersonal space processing. In addition to that, analyses revealed characteristic bilateral activation patterns of primary to tertiary visual areas, extending dorsally from the lateral occipital cortex to the posterior intraparietal sulcus for stimuli in peripersonal space, while extrapersonal space activated mostly ventral regions of the tertiary visual cortex. Notably, as the first study to control for pixel object size, these patterns persist, indicating that stimuli in peripersonal space engage the dorsal visual stream, potentially reflecting action-oriented and grasping feature encoding linked to their interactive affordances, while stimuli in extrapersonal space engage ventral regions primarily mediating semantic aspects and scene analysis.
大脑通过不同的神经网络处理可触及的个人周边空间和不可触及的个人外部空间中的物体。与个人外部空间不同，个人周边空间中的空间处理与背侧视觉通路中可供性的激活相关联。然而，关于物体特征（如大小、可抓握性和立体呈现）如何影响虚拟环境中物体处理的文献仍不明确。在当前研究中，44名健康参与者执行了一项视觉辨别任务，该任务涉及在个人周边空间和个人外部空间中呈现的可抓握物体。该范式在功能磁共振成像扫描期间通过与磁共振成像兼容的护目镜呈现。四个阶段在单视场和立体呈现之间交替，并且刺激在各阶段内的视距、大小和方向上有所变化。为了验证距离的影响，还控制了物体的像素大小。立体呈现增强了背侧流激活，特别是在V5/MT、枕外侧皮层和顶内后沟，这些区域与深度处理相关，表明个人周边空间处理增加。除此之外，分析揭示了从初级视觉区域到三级视觉区域的特征性双侧激活模式，对于个人周边空间中的刺激，从枕外侧皮层向背侧延伸至顶内后沟，而个人外部空间主要激活三级视觉皮层的腹侧区域。值得注意的是，作为第一项控制物体像素大小的研究，这些模式持续存在，表明个人周边空间中的刺激激活了背侧视觉流，可能反映了与其交互可供性相关的以行动为导向和抓握特征编码，而个人外部空间中的刺激主要激活腹侧区域，主要介导语义方面和场景分析。
