研究期間：10108~10207;Orienting oneself in the environment is a crucial ability for survival. At least two distinct spatial reference frames for orienting can be distinguished based on the origin of the underlying coordinate system and the information that is stored in the resultant representation: an egocentric reference frame and an allocentric reference frame. Individuals differ in their proclivity, or natural tendency, in making use of spatial reference frames. To date, despite a number of attempts to examine the neural underpinnings for different spatial reference frames, no study has examined individual differences in the precise brain loci for egocentric and allocentric representations when they are being accessed online. The current project aims to characterize functional properties of brain regions associated with spatial orientation, with an emphasis on individual differences. Three series of experiments will be carried out to look into regions of interest (ROI) for spatial reference frames, possibly including the posterior parietal cortex, medial temporal regions (hippocampus and parahippocampal areas), striatum, as well as premotor cortex. A heading computation paradigm in virtual environments will be used to categorize participants’ proclivity in allocentric and egocentric reference. After determining an individual’s preferred reference frame, we will parametrically manipulate the geometry of environmental structures (Experiment Series 1), the amount and types of landmarks in the environment (Experiment Series 2), and the mode of responses carried out by the participants (Experiment Series 3). The neural networks associated with online performance in these scenarios will be assessed with functional magnetic resonance imaging (fMRI), and the differences in behavioral performance and activation in neural networks between egocentric and allocentric groups will be compared. Results of this project will not only complement existing knowledge from EEG studies about the neural dynamics for spatial orientation, but also shed light on how various environmental and individual factors modulates the utilization of allocentric and egocentric spatial representations.
