Effects of tACS on Episodic Memory Consolidation in Older Adults

Memory consolidation involves post-encoding processes that stabilize newly acquired memories over time and is thought to be supported by neural oscillatory activity in specific frequency ranges. Transcranial alternating current stimulation (tACS) allows noninvasive modulation of rhythmic brain activity and may influence consolidation processes when administered after learning. The present study examines whether frequency-specific tACS stimulation administered immediately after encoding affects the early consolidation of human episodic memory of older adults. Participants complete an object-learning task followed by free-recall tests, after which they receive 20 minutes of tACS at either 3 Hz (theta) or 16 Hz (beta) or sham, in a double-blind design. Memory performance is assessed immediately after stimulation, as well as after 24 hours and one week, to evaluate retention across time.