Beyond encoding: Brain mechanisms of memory integration and skill enhancement

Abstract

Memory is not merely about encoding—it is a dynamic process that continues to evolve long after initial acquisition. Once formed, memories undergo various unconscious processes in the brain. In this talk, I will explore post-encoding integration and enhancement, focusing on implicit memory and motor skill learning. First, I will introduce our research on the integration of implicit memories. We found that when participants learn a sequence of objects, they simultaneously acquire a false memory of the reverse order, and these memories integrate over time. The anterior part of the hippocampus was involved in this process. These results suggest that time-dependent memory integration may contribute to cognitive error such as affirming-the-consequent fallacy. Second, I will present our ongoing research on reactivation of once-consolidated motor skill. Using exoskeleton-assisted movement reconstruction, we demonstrated that somatosensory feedback is essential for motor skill enhancement through reactivation—while voluntary execution of movement itself is not required. Furthermore, by applying decoding techniques to EEG data, we found that activity patterns corresponding to motor skills are reinstated in the brain after reactivation. These findings suggest that post-encoding brain processes play a crucial role in abstracting and strengthening acquired memories. Understanding these mechanisms provides new insights into how the unconscious process in the brain shapes and refines memories beyond initial learning. 

Bio

Dr. Shibata obtained a PhD in Science from Nara Institute of Science and Technology in 2008. He subsequently worked at the Advanced Telecommunications Research Institute International (ATR), Boston University, and Brown University as a postdoctoralresearcher; Nagoya University as an associate professor; and the National Institute for Quantum Science and Technology as a principal researcher. He currently leads the Lab for Human Cognition and Learning at RIKEN Center for Brain Science as a team director.

https://scholar.google.com/citations?user=MtolH1MAAAAJ