Chrastil Elizabeth R, Sherrill Katherine R, Hasselmo Michael E, Stern Chantal E
Department of Psychological and Brain Sciences and Center for Memory and Brain, Boston University, Boston, Massachusetts 02215, and Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129
Department of Psychological and Brain Sciences and Center for Memory and Brain, Boston University, Boston, Massachusetts 02215, and Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129.
J Neurosci. 2015 Nov 18;35(46):15442-52. doi: 10.1523/JNEUROSCI.1209-15.2015.
Path integration, the updating of position and orientation during movement, often involves tracking a home location. Here, we examine processes that could contribute to successful location tracking in humans. In particular, we investigate a homing vector model of path integration, whereby a navigator continuously tracks a trajectory back to the home location. To examine this model, we developed a loop task for fMRI, in which participants viewed movement that circled back to a home location in a sparse virtual environment. In support of a homing vector system, hippocampus, retrosplenial cortex, and parahippocampal cortex were responsive to Euclidean distance from home. These results provide the first evidence of a constantly maintained homing signal in the human brain. In addition, hippocampus, retrosplenial cortex, and parahippocampal cortex, as well as medial prefrontal cortex, were recruited during successful path integration. These findings suggest that dynamic processes recruit hippocampus, retrosplenial cortex, and parahippocampal cortex in support of path integration, including a homing vector system that tracks movement relative to home.
Path integration is the continual updating of position and orientation during navigation. Animal studies have identified place cells and grid cells as important for path integration, but underlying models of path integration in humans have rarely been studied. The results of our novel loop closure task are the first to suggest that a homing vector tracks Euclidean distance from the home location, supported by the hippocampus, retrosplenial cortex, and parahippocampal cortex. These findings suggest a potential homing vector mechanism supporting path integration, which recruits hippocampus and retrosplenial cortex to track movement relative to home. These results provide new avenues for computational and animal models by directing attention to homing vector models of path integration, which differ from current movement-tracking models.
路径整合，即在运动过程中对位置和方向的更新，通常涉及追踪一个家的位置。在此，我们研究可能有助于人类成功进行位置追踪的过程。具体而言，我们调查了路径整合的归巢向量模型，即导航者持续追踪一条返回家位置的轨迹。为了检验这个模型，我们开发了一个用于功能磁共振成像（fMRI）的环路任务，其中参与者在一个稀疏的虚拟环境中观看循环回到家位置的运动。支持归巢向量系统的是，海马体、压后皮质和海马旁皮质对离家的欧几里得距离有反应。这些结果提供了人类大脑中持续维持的归巢信号的首个证据。此外，在成功的路径整合过程中，海马体、压后皮质、海马旁皮质以及内侧前额叶皮质都被激活。这些发现表明，动态过程会激活海马体、压后皮质和海马旁皮质以支持路径整合，包括一个追踪相对于家的运动的归巢向量系统。
路径整合是导航过程中位置和方向的持续更新。动物研究已确定位置细胞和网格细胞对路径整合很重要，但人类路径整合的潜在模型很少被研究。我们新颖的环路闭合任务的结果首次表明，归巢向量追踪离家的欧几里得距离，这由海马体、压后皮质和海马旁皮质支持。这些发现表明存在一种潜在的支持路径整合的归巢向量机制，该机制会激活海马体和压后皮质以追踪相对于家的运动。这些结果通过将注意力引向与当前运动追踪模型不同的路径整合归巢向量模型，为计算模型和动物模型提供了新途径。
