Take a look at the image to the left, and imagine that the gray blocks are made out of heavy stone, and that the green blocks are made out of a light plastic. Which direction will this tower fall? How do you know?
Many people report that they know the answer because they can visually imagine what it will look like when the tower falls. In other words, they solve the problem using a type of mental simulation, which is the ability to imagine actions, percepts, and even realities that exist only in our minds.
There is evidence for mental simulation in almost every area of cognition: many problems can be solved by visualizing the solution; athletes can train by mentally simulating motor actions; we can predict the physical world by imagining how objects interact; and we can reason through counterfactuals by simulating alternate realities.
I want to understand the computational nature of mental simulation. In particular, I am interested in questions such as, why do we use mental simulation? That is, what problem does simulation solve, that other strategies cannot? How do we decide when to use simulation, rather than an alternative? How do we determine what simulations to run? How many simulations should we run, and for how long? My research attempts to answer these questions through a combination of rational analysis, formal mathematical modeling, and psychophysical experiments.