Using fast visual rhythmic stimulation to control inter-hemispheric phase offsets in visual areas

Spike timing dependent plasticity (STDP) is believed to be important for neural communication and in human episodic memory, but causal evidence lacking due technical challenges. Rhythmic sensory stimulation that has been used investigate relations between oscillations cognition may able address this question. The challenge, however, the frequency corresponding critical time window STDP gamma (~40 Hz), yet application of rhythmic limited primarily lower frequencies (<30 Hz). It remains unknown whether method can applied precisely control activation delay distant groups neurons at a millisecond scale. To answer question examine role we simulated function by controlling left right visual cortices during memory encoding. This was achieved presenting flickering (37.5 Hz) movie pairs fields with phase lag either 0, 90, 180 or 270°. Participants were asked memorize two movies within each pair association later tested. Behavioral results revealed no significant difference performance across conditions different degrees synchrony. Yet importantly, our study showed first time, oscillatory activity driven precision 6.67 ms neuronal groups. Our hereby provides an approach precise cognitive functions.