Direct electrical brain stimulation of human memory: lessons learnt and future perspectives.

The article focuses on the modulation of human declarative memory through direct electrical stimulation (DES) of the brain, highlighting the challenges and advances in understanding its neurophysiological mechanisms and therapeutic potential. It reviews various invasive DES approaches—continuous and phasic, open- and closed-loop stimulation—and emphasizes the importance of electrophysiological biomarkers, such as intracranial EEG (iEEG) spectral activities, for predicting and optimizing memory enhancement outcomes. The authors discuss adaptive stimulation, which uses real-time biomarker analysis and machine-learning tools to adjust stimulation parameters over extended periods, offering promising avenues for chronic treatment of memory deficits in neurological and neuropsychiatric disorders. Despite technological progress, the article notes that consistent long-term effects and validated biomarkers remain limited, and further research is needed to clarify optimal strategies and address ethical considerations in modulating human memory.