Targeting the dorsolateral prefrontal cortex to enhance memory control: divergent effects on social and non-social memories

Voluntary forgetting, governed by top-down inhibitory control in the prefrontal cortex, plays a critical role in adaptive memory regulation. This study investigated the causal role of the right dorsolateral prefrontal cortex (rDLPFC) in the forgetting of social and non-social memories. Employing high-frequency (10 Hz) repetitive transcranial magnetic stimulation (rTMS) in an offline protocol, we modulated rDLPFC activity (Active TMS condition) and compared it to a Control TMS condition targeting the vertex. Participants completed a directed forgetting (DF) task framed in social and non-social contexts. Results revealed a dissociation in rDLPFC involvement: stimulation significantly enhanced the forgetting of negative non-social memories but did not affect social memories. Furthermore, rTMS moderated the relationship between social anxiety and forgetting performance: individuals with higher social anxiety struggled to forget negative social feedback in the Control TMS condition, a difficulty alleviated by rDLPFC stimulation. These findings suggest that voluntary forgetting of social and non-social memories engages distinct neural mechanisms and highlighting rDLPFC stimulation as a potential intervention for reducing maladaptive memory biases associated with social anxiety.