Baseline dynamics in human visual behaviour.

Humans perceive their visual environment by directing their eyes towards relevant objects. The deployment of visual attention depends substantially on stimulus properties, higher cognitive processes, and biases and constraints of the visual system. Numerous models describe human eye movements depending on the task or content. However, there is no universal, context-invariant model of human gaze behaviour. Here, we show that statistical regularities can be utilised to model human gaze behaviour regardless of task, observer, and stimulus. Using a context-agnostic eye movement model with a fixed transition kernel, we can predict human saccade lengths in various viewing situations better than a baseline model which randomly samples from the pooled empirical distribution. Thus, contrary to current belief, human gaze patterns follow baseline dynamics, making them comparable across contexts. Since gaze behaviour is directly related to brain structure, our results provide evidence for the existence of an underlying, context-invariant component in the human visual system.