实地导航训练提高大脑功能连接模式稳定性

Spatial navigation involves both egocentric (body-centered) and allocentric (environment-centered) spatial representations, which are hosted in structurally and functionally segregated brain regions. The two types of representations are flexibly weighted in response to changing environmental cues and landmarks during the navigational process, thereby achieving a stable and robust neural code of the target location. However, it remains unknown whether and how improvements of real-world navigational proficiency are related to these two types of spatial representations.<br />In the present study, participants that were strange to the campus layout (newly arrived university freshmen) received a real-world navigation training for 20 days. Before and after the training, participants received fMRI scanning when they performed a distance judgment task and a paper folding task (as control), and were comprehensively tested for their navigational ability via several behavioral tasks (live pointing, offsite direction estimation and offsite distance estimation) outside the scanner. A control group comprised of participants who did not receive any training underwent the same fMRI scanning and behavioral tests. By comparing the training-induced changes in regional activation and the task-based global functional connectivity (FC) patterns between the two groups, we investigated the neural correlates underlying the improvement of real-world navigation performance.<br />We found that the real-world navigation training improved participants performance in all behavioral tasks. At the neural level, we observed a significant training-induced activation enhancement in right superior parietal lobule (rSPL), a core brain region that hosts egocentric representation. Moreover, training increased the global FC pattern stability with rSPL as the seed region during the distance judgment task, but had no significant effects on the FC pattern stability during the baseline task. Finally, the increase in the global FC pattern stability also predicted individuals improvement of behavioral performance in the distance judgment task. Notably, these effects were only found in the trained group, while no similar observations were made in the control group. These findings indicated that improvement of real-word navigation ability was associated with enhanced egocentric representation. Moreover, navigation training consolidated the information exchange routes among brain regions, thereby enhancing the precision of cognitive map retrieval.<br />In summary, our study highlights the importance of egocentric representation enhancement in rSPL to improving real-world navigation ability in unfamiliar environments. Furthermore, navigation training facilitates spatial information retrieval by reinforcing the information exchange pathways between rSPL and other brain areas.