Memory signals from the thalamus: early thalamocortical phase synchronization entrains gamma oscillations during long-term memory retrieval.

摘要: Abstract The thalamus is believed to be a key node in human memory networks, however, very little known about its real-time functional role. Here we examined the dynamics of thalamocortical communication during long-term episodic retrieval two experiments. In Experiment 1, intrathalamic and surface EEG was recorded an epileptic patient implanted with depth electrodes for brain stimulation therapy. recognition test, early (300–500 ms) stimulus-linked oscillatory synchrony between mediodorsal thalamic frontal at beta frequency (20 Hz) enhanced correctly remembered old compared rejected new items. Directionality measures (Granger causality) indicated that sender, neocortex receiver, this signal, which also modulated power neocortical gamma (55–80 Hz) oscillations (cross-frequency coupling). 2 validated cross-frequency coupling effects healthy participant sample. Confirming findings from significantly increased found over scalp successful recognition. Extending anatomical knowledge on connectivity neocortex, these results suggest sends signal regions, triggering further search processes.