Regeneration

Neurons can also be added to an existing layer i>1. Initialisation is similar to the case of a new layer except that the vector quantisation (or another method) is now applied to the reconstruction errors s_i-1(t)-m_i-1^s(t) concatenated with u_i-1(t)-m_i-1^u(t). The procedure of removing dead neurons and adding some new ones is called ``regeneration''. New neurons are in greater danger to be pruned away but Section introduces ways to protect them.