Neurocomputation and Neuroimaging Unit, Department of Education and Psychology, Freie Universität Berlin, Berlin, Germany.
Center for Cognitive Neuroscience Berlin, Freie Universität Berlin, Berlin, Germany.
Sci Rep. 2017 Nov 30;7(1):16659. doi: 10.1038/s41598-017-16848-7.
To represent one's upper limbs for action, the brain relies on a combined position estimate based on visual and proprioceptive information. Monkey neurophysiology and human brain imaging suggest that the underlying operations are implemented in a network of fronto-parietal and occipitotemporal cortical areas. Recently, a potential hierarchical arrangement of these areas has been proposed, emphasizing the posterior parietal cortex (PPC) in early multisensory comparison and integration. Here, we used functional magnetic resonance imaging (fMRI) and a virtual reality-based setup to briefly (0.5 s) present healthy human participants photorealistic virtual hands, of matching or nonmatching anatomical side, or objects at the same or a different location than their real hidden left or right hand. The inferior parietal lobe (IPL) of the left PPC showed a significant preference for congruent visuoproprioceptive hand position information. Moreover, the left body part-selective extrastriate body area (EBA; functionally localized) significantly increased its coupling with the left IPL during visuoproprioceptive congruence vs. incongruence. Our results suggest that the PPC implements early visuoproprioceptive comparison and integration processes, likely relying on information exchange with the EBA.
为了进行上肢动作的表达,大脑依赖于基于视觉和本体感觉信息的组合位置估计。猴子神经生理学和人类脑成像表明,这些操作是由额顶和枕颞皮质区域的网络实现的。最近,有人提出了这些区域的潜在层次结构,强调了后顶叶皮层(PPC)在早期多感觉比较和整合中的作用。在这里,我们使用功能磁共振成像(fMRI)和基于虚拟现实的设置,短暂地(0.5s)向健康的人类参与者呈现匹配或不匹配解剖侧的逼真虚拟手,或者与真实隐藏的左手或右手相同或不同位置的物体。左顶叶皮层(PPC)的下顶叶显示出对一致的视觉本体感觉手位置信息的明显偏好。此外,在视觉本体感觉一致与不一致的情况下,左侧身体部位选择性的外纹状体身体区域(EBA;功能定位)与左侧 IPL 的耦合显著增加。我们的结果表明,PPC 执行早期的视觉本体感觉比较和整合过程,可能依赖于与 EBA 的信息交换。