Peripheral nerve stimulation using tDCS can enhance reconsolidation but cannot mitigate retrieval-induced forgetting
Biological psychology
Biol Psychol. 2026 Feb 28:109229. doi: 10.1016/j.biopsycho.2026.109229. Online ahead of print.
ABSTRACT
INTRODUCTION: Memory reconsolidation refers to the process by which reactivated memories are rendered labile - and can be further strengthened or become sensitive to disruption. This study investigated whether non-invasive transcutaneous electrical stimulation of the greater occipital nerve (NITESGON) using direct current stimulation (tDCS) can modulate reconsolidation processes.
METHODS: In a randomised, double-blind, placebo-controlled experiment, 38 healthy participants completed a Swahili-English paired-association task across three sessions over two consecutive days. Active or sham NITESGON was applied during reconsolidation, to test its effects on retrieval practice and retrieval-induced forgetting.
RESULTS: Active NITESGON significantly enhanced memory reconsolidation, as evidenced by superior retrieval of previously consolidated pairs (i.e. no-change pairs) compared to sham stimulation. However, critically, we demonstrate that NITESGON did not mitigate retrieval-induced forgetting: both groups exhibited greater forgetting of competing associations (competing pairs) than non-competing ones (original pairs). This study also highlights how active NITESGON (compared to sham) significantly enhanced consolidation, but not acquisition or forgetting processes.
CONCLUSION: These findings demonstrate that peripheral nerve stimulation via tDCS can strengthen reconsolidation through retrieval practice, but does not alter retrieval-induced forgetting. This work elucidates the stage-specific influence of peripheral nerve stimulation on memory processes and highlights its potential translational value for conditions involving memory dysfunction.
