Before revision:  Finally we present calculations that allow our techniques to approximate time-varying Ornstein-Uhlenbeck processes . By presenting these explicit formulae, we aim to foster the development of refined numerical methods and analytical techniques for studying diffusion decision processes with time-varying drift rates and thresholds .
After revision:  Finally we present calculations that allow our techniques to approximate time-varying Ornstein-Uhlenbeck processes . By presenting these explicit formulae, we aim to foster the development of refined numerical methods and analytical techniques for studying diffusion decision processes with time-varying evidence .