I guess pretty much what they do in CV:
Skip connections or residual connections are used to allow gradients to flow through a network directly, without passing through non-linear activation functions. Non-linear activation functions, by nature of being non-linear, cause the gradients to explode or vanish (depending on the weights). Skip connections form conceptually a ‘bus’ which flows right the way through the network, and in reverse, the gradients can flow backwards along it too.