Reservoir Computing

Synonyms

Echo state network; Liquid state machine

Definition

Reservoir computing is an approach to sequential processing where recurrency is separated from the output mapping (Jaeger, 2003; Maass, Natschlaeger, & Markram, 2002). The input sequence activates neurons in a recurrent neural network (a reservoir, where activity propagates as in a liquid). The recurrent network is large, nonlinear, randomly connected, and fixed. A linear output network receives activation from the recurrent network and generates the output of the entire machine. The idea is that if the recurrent network is large and complex enough, the desired outputs can likely be learned as linear transformations of its activation. Moreover, because the output transformation is linear, it is fast to train. Reservoir computing has been successful in particular in speech and language processing and vision and cognitive neuroscience.