  What makes humans so good at solving seemingly complex video games? Unlike
computers, humans bring in a great deal of prior knowledge about the world,
enabling efficient decision making. This paper investigates the role of human
priors for solving video games. Given a sample game, we conduct a series of
ablation studies to quantify the importance of various priors on human
performance. We do this by modifying the video game environment to
systematically mask different types of visual information that could be used by
humans as priors. We find that removal of some prior knowledge causes a drastic
degradation in the speed with which human players solve the game, e.g. from 2
minutes to over 20 minutes. Furthermore, our results indicate that general
priors, such as the importance of objects and visual consistency, are critical
for efficient game-play. Videos and the game manipulations are available at
https://rach0012.github.io/humanRL_website/
