The cause of this refractory state is unknown.

Some time after the excitation element switches to the refractory state, being in which it can not be excited.

This decreases the chance of re-entry depolarization, because signals are more likely to encounter tissue in a refractory state which can't be excited.

This can generate impulses conducted in both directions along this axon since no part of the axon is in a refractory state.

Refractoriness is the fundamental property of any object of autowave nature (especially excitable medium) not to respond on stimuli, if the object stay in the specific refractory state.

Among their findings is that if the initial pattern contains no cells in the refractory state then the pattern will die out in any bounded region, leaving only quiescent cells.