The ability to predict and take action in response to a stimulus is necessary for human survival. Fortunately, humans are physics masters capable of predicting how objects behave and this ability can be attributed to the so-called physics engine of the brain.

The engine comes alive when people witness physical events happen. Now, findings of a new study set to be published in the journal Proceedings of the National Academy of Sciences, revealed where the physics engine is located.

Researchers discovered that it is not found in the vision center of the brain but rather in a set of regions involved in planning actions. This suggests that the human brain constantly make real-time physics calculations so people can quickly come up with necessary actions such as to catch, dodge, or hoist.

The discovery may help scientists design better robots as well as shed light on movement disorders such as apraxia. Researchers think it is possible that people with damage to the brain's motor areas may also have trouble making physical judgements.

Study researcher Jason Fischer, from Johns Hopkins University, and colleagues conducted a series of experiments to determine the parts of the brain that play a role in physical inference.

Fischer and colleagues asked participants to look at videos of Jenga-style block towers and to predict where the blocks would likely land if the tower topples. The participants were also asked to guess if the tower have more yellow or blue blocks. The ability to predict the direction of the falling blocks involves physical intuition while guessing the color of the blocks was visual.

The researchers also asked participants to look at a video of two dots that bounce around the screen and had them predict where the dots were headed.

Based on the observed brain activities of the participants, the researchers found that when they try to predict the physical outcomes of the blocks and dots, the most responsive of their brain regions include those in the action planning areas of the brain.

When the participants were asked to watch short movie clips, the researchers found that the clips with more physics content is linked with activation of more key brain regions.

"The brain activity reflected the amount of physical content in a movie, even if people weren't consciously paying attention to it," Fischer said explaining that this shows people make physical inferences all the time regardless that they do not even think about it.