Neuroplasticity primarily occurs during sleep, especially the night following focused learning.

“it is really during sleep and other states of deep relaxation things like meditation and non-sleep deep rest which I've talked about before on this podcast but really during our main night of sleep that the rewiring of neural connections that is the actual neuroplasticity takes place”

“there are what are called second and third night effects also once you sleep you will learn those neuroplastic events the reordering of connections that we call synapses and the changes that occur in neural circuits that reflects what we call self-directed adaptive plasticity that still will occur but ideally you got a great night's sleep on the first night following trying to learn and the second night and the third and so on and so on on”