With experience we become accustomed to the types of environments that we normally encounter as we navigate in the world. But how does this fundamental knowledge develop in the first place and what brain regions are involved? To examine de novo environmental learning, we created an 'alien' virtual reality world populated with landmarks of which participants had no prior experience. They learned about this environment by moving within it during functional MRI (fMRI) scanning while we tracked their evolving knowledge. Retrosplenial cortex (RSC) played a central and highly selective role by representing only the most stable, permanent features in this world. Subsequently, increased coupling was noted between RSC and hippocampus, with hippocampus then expressing knowledge of permanent landmark locations and overall environmental layout. Studying how environmental representations emerge from scratch provided a new window into the information processing underpinning the brain's navigation system, highlighting the key influence of the RSC.
Human subjects: The studies were approved by the University College London Research Ethics Committee: #1825/003 Minimum Risk Magnetic Resonance Imaging Studies of Healthy Human Cognition. Written informed consent was obtained from each participant for participation in the study, for data analysis and for publication of the study results.
- Howard Eichenbaum, Boston University, United States
© 2015, Auger et al.
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