Without having access to the paper, it would be really nice to see what model of attention they're using, and how it relates to the expected-reward calculations

Without having access to the paper, it would be really nice to see what model of attention they're using, and how it relates to the expected-reward calculations they're positing take place for reinforcement learning. I'd also like to see the authors explain whether the model-free or model-based RL controller in the brain is the one operating to update endogenous attention based on expected value.