AUTHOR=Martinolli Marco , Gerstner Wulfram , Gilra Aditya TITLE=Multi-Timescale Memory Dynamics Extend Task Repertoire in a Reinforcement Learning Network With Attention-Gated Memory JOURNAL=Frontiers in Computational Neuroscience VOLUME=12 YEAR=2018 URL=https://www.frontiersin.org/journals/computational-neuroscience/articles/10.3389/fncom.2018.00050 DOI=10.3389/fncom.2018.00050 ISSN=1662-5188 ABSTRACT=

The interplay of reinforcement learning and memory is at the core of several recent neural network models, such as the Attention-Gated MEmory Tagging (AuGMEnT) model. While successful at various animal learning tasks, we find that the AuGMEnT network is unable to cope with some hierarchical tasks, where higher-level stimuli have to be maintained over a long time, while lower-level stimuli need to be remembered and forgotten over a shorter timescale. To overcome this limitation, we introduce a hybrid AuGMEnT, with leaky (or short-timescale) and non-leaky (or long-timescale) memory units, that allows the exchange of low-level information while maintaining high-level one. We test the performance of the hybrid AuGMEnT network on two cognitive reference tasks, sequence prediction and 12AX.