Thesis defense Wei Liu (Donders series 454)
28 October 2020
Our memories are not static, but quite dynamic. My experimental works revealed memory dynamics in both the temporal and strength domain: (1) The brain uses separate neural states to segment information into events and simultaneously binds them into a coherent narrative but needs to reconfigure its neural states in time to enable flexible retrieval and suppression of memories during task switching. (2) Repeated retrieval promotes episode-unique mnemonic representations, leading to enhanced memory strength. By contrast, repeated suppression disengages prefrontal involvement during retrieval, causing compromised memory strength. These changes in memory strength are associated with changes in the emotional intensity of individual memory traces. This dual modulation phenomenon is supported by the common inhibitory control network and corresponding transcriptional correlates. These results might lead to non-pharmacological, cognitive approaches that can enhance the encoding efficiency and persistence of everyday memories or can modify traumatic memories and reduce their emotional impacts.