It's hard to tell since there's no context but one way I interpreted it is that he used to think it was mostly only the established synapses were changing. Inst

It's hard to tell since there's no context but one way I interpreted it is that he used to think it was mostly only the established synapses were changing. Instead, with this new result, perhaps he sees many more synapses being formed, not just existing synapses changing their strength.