Method of loci training yields unique prefrontal representations that support effective memory encoding

Abstract

The method of loci is a technique to effectively boost memory, but its impact on the underlying neural representations is poorly understood. Here, we used functional magnetic resonance imaging and representational similarity analysis to compare the neural representations of memory athletes ranked among the worlds top 50 in memory sports to those of mnemonics-naive controls. In a second study, mnemonics-naive individuals underwent a 6-week-long memory training, working memory training, or no intervention. Results showed distinct neural representations in the prefrontal cortex, inferior temporal, and posterior parietal regions as memory athletes and the memory training group studied novel content. Neural representations were also distinct between these experienced individuals, which was related to better memory performance after 4 months. In parallel, the data revealed increased neural pattern similarity in the anterior hippocampus and precuneus, suggesting a more generalised role of these regions in episodic memory formation and retrieval. Our findings highlight how extensive memory training affects neocortical memory engrams. We suggest that the method of loci may bolster memory uniqueness within ones "memory palace", setting the stage for exceptional memory performance.