In our experiments, individual sentences are presented in a single line on a screen, thus we only model a horizontal gaze position s t ∈ R. At test time, we observe novel eye movement patternsS = {S 1 , .
we model the distribution over the saccade amplitude given the saccadic type (Equation 4) as truncated Gamma distributions, given by 1 is the Gamma distribution with shape parameter α and scale parameter β, and Γ is the Gamma function.