RT Journal Article SR Electronic T1 Clustering and compositionality of task representations in a neural network trained to perform many cognitive tasks JF bioRxiv FD Cold Spring Harbor Laboratory SP 183632 DO 10.1101/183632 A1 Yang, Guangyu Robert A1 Song, H. Francis A1 Newsome, William T. A1 Wang, Xiao-Jing YR 2017 UL http://biorxiv.org/content/early/2017/09/01/183632.abstract AB A neural system has the ability to flexibly perform many tasks, but the underlying mechanism cannot be elucidated in traditional experimental and modeling studies designed for one task at a time. Here, we trained a single network model to perform 20 cognitive tasks that may involve working memory, decision-making, categorization and inhibitory control. We found that after training, recurrent units developed into clusters that are functionally specialized for various cognitive processes. We introduce a measure to quantify relationships between single-unit neural representations of tasks, and report five distinct types of such relationships that can be tested experimentally. Surprisingly, our network developed compositionality of task representations, a critical feature for cognitive flexibility, whereby one task can be performed by recombining instructions for other tasks. Finally, we demonstrate how the network could learn multiple tasks sequentially. This work provides a computational platform to investigate neural representations of many cognitive tasks.