Real-time fMRI feedback transforms mental strategies into tools for self-regulating hippocampal activity

The hippocampus is essential for recalling the past and envisioning the future, and its disruption has major consequences for aging and mental health. While external neurostimulation tools show promise in modulating hippocampal activity, effective real-world interventions require individuals to flexibly self-regulate this system. Here, we show, across two real-time fMRI neurofeedback studies (N = 141), that individuals can learn to upregulate hippocampal activity through mental strategies linked to its core functions. Crucially, the effective use of such strategies depended critically on contingent neurofeedback; without valid neurofeedback, these strategies did not predict the capacity for hippocampal upregulation. Subfield analyses revealed the strongest effects in the subiculum, an integrative hub connecting hippocampal processing to broader cognitive and affective networks. Together, these findings suggest that real-time fMRI feedback reinforces the use of self-generated mnemonic strategies to achieve voluntary control over hippocampal activity—a learned form of self-regulation that may enhance everyday memory function and inform interventions for memory-related disorders.