Figure 1:

High-level overview of the flow of learning activity during awake and replay stages in biological networks versus artificial neural networks (ANNs). While replay occurs in several brain regions both independently and concurrently, replay in most artificial implementations occurs concurrently from a single layer. While the hippocampal complex (HC) can be used for both replay and inference in biological networks, the memory buffers in artificial replay implementations are mostly used to train the neural network that makes predictions. Figure (a) illustrates replay in biological networks. Figures (b) and (c) are examples of replay in an ANN with 3 hidden layers. For networks with more layers, the layer for representational replay can be chosen in a variety of ways (see text).