Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, London, United Kingdom.
PLoS One. 2012;7(8):e43620. doi: 10.1371/journal.pone.0043620. Epub 2012 Aug 17.
Landmarks are critical components of our internal representation of the environment, yet their specific properties are rarely studied, and little is known about how they are processed in the brain. Here we characterised a large set of landmarks along a range of features that included size, visual salience, navigational utility, and permanence. When human participants viewed images of these single landmarks during functional magnetic resonance imaging (fMRI), parahippocampal cortex (PHC) and retrosplenial cortex (RSC) were both engaged by landmark features, but in different ways. PHC responded to a range of landmark attributes, while RSC was engaged by only the most permanent landmarks. Furthermore, when participants were divided into good and poor navigators, the latter were significantly less reliable at identifying the most permanent landmarks, and had reduced responses in RSC and anterodorsal thalamus when viewing such landmarks. The RSC has been widely implicated in navigation but its precise role remains uncertain. Our findings suggest that a primary function of the RSC may be to process the most stable features in an environment, and this could be a prerequisite for successful navigation.
地标是我们对环境内部表示的关键组成部分，但它们的具体属性很少被研究，并且对于它们在大脑中是如何被处理的知之甚少。在这里，我们对一系列特征的地标进行了大量特征描述，这些特征包括大小、视觉显著性、导航实用性和永久性。当人类参与者在功能磁共振成像 (fMRI) 期间观看这些单个地标图像时，旁海马回皮质 (PHC) 和后扣带回皮质 (RSC) 都被地标特征所激活，但方式不同。PHC 对一系列地标属性做出反应，而 RSC 只对最持久的地标做出反应。此外，当参与者被分为优秀和较差的导航者时，后者在识别最持久地标时的可靠性明显降低，并且在观看这些地标时，RSC 和前背侧丘脑的反应减弱。RSC 广泛参与导航，但它的确切作用仍不确定。我们的研究结果表明，RSC 的主要功能之一可能是处理环境中最稳定的特征，这可能是成功导航的前提。
