Fig. 4

Learning-forgetting-relearning behavior. a Schematic diagram of the “learning-forgetting-relearning” behavior. b Learning-forgetting-relearning behavior with seven cycles. c The “learning experience” behavior was measured under UV light pulse (254 nm) stimulation. Light intensity: 1.8 mW cm^–2, pulse width: 3 s, pulse interval: 3 s