  Despite the remarkable success of deep learning systems over the last decade,
a key difference still remains between neural network and human
decision-making: As humans, we cannot only form a decision on the spot, but
also ponder, revisiting an initial guess from different angles, distilling
relevant information, arriving at a better decision. Here, we propose
RecycleNet, a latent feature recycling method, instilling the pondering
capability for neural networks to refine initial decisions over a number of
recycling steps, where outputs are fed back into earlier network layers in an
iterative fashion. This approach makes minimal assumptions about the neural
network architecture and thus can be implemented in a wide variety of contexts.
Using medical image segmentation as the evaluation environment, we show that
latent feature recycling enables the network to iteratively refine initial
predictions even beyond the iterations seen during training, converging towards
an improved decision. We evaluate this across a variety of segmentation
benchmarks and show consistent improvements even compared with top-performing
segmentation methods. This allows trading increased computation time for
improved performance, which can be beneficial, especially for safety-critical
applications.
