This paper proposes a biologically inspired incremental learning method for spatio-temporal patterns based on our recently reported “Incremental learning through sleep (ILS)” method. This method alternately repeats two learning phases: awake and sleep. During the awake phase, the system learns new spatio-temporal patterns by rote, whereas in the sleep phase, it rehearses the recorded new memories interleaved with old memories. The rehearsal process is essential for reconstructing the internal representation of the neural network so as not only to memorize the new patterns while keeping old memories but also to reduce redundant hidden units. By using this strategy, the neural network achieves high generalization ability.