Whenever we see interactions between physical objects in the world, we intuitively make predictions of the possible outcome, even if we’re not consciously aware that we’re doing it.
Interestingly, however, our predictions of the future in this particular sense have less to do with vision and more to do with the brain’s “physics engine”, reports a team of US researchers, writing in the Proceedings of the National Academy of Sciences.
“We run physics simulations all the time to prepare us for when we need to act in the world,” explains lead author Jason Fischer, a psychologist at John’s Hopkins University. “It is among the most important aspects of cognition for survival. But there has been almost no work done to identify and study the brain regions involved in this capability.”
To see which parts of the brain light up when faced with a physics puzzle, the research team devised three separate experiments.
First, 12 participants were asked to watch videos depicting towers of coloured blocks – something akin to a mix of Lego and Jenga – and predict how they will fall when toppled. As a control, the participants were also asked to describe the colour of the blocks they were seeing.
Questions relating to the first task were found to kick off a specific neural network in the frontal and parietal cortices, which overlaps with parts of our brain responsible for action planning and tool use. Questions about colour, on the other hand, engaged only the regions responsible for sight.
In the second experiment, participants had to watch a video of dots bouncing around on a screen and try to predict the next movement. Surely enough, the same network was activated.
Finally, brain activity was recorded while participants watched movie clips, some of which contained physical objects interacting in complex ways. Whenever such an interaction occurred on the screen, the “physics engine” revved up, suggesting it’s mostly automatic, requiring little to no conscious effort.
“The brain activity reflected the amount of physical content in a movie, even if people weren’t consciously paying attention to it, “Fischer explained. “This suggest that we are making physical inferences all the time, even when we’re not even thinking about it.”
The authors contend that better understanding of how our brains deal with physics could lead to more advanced robotics somewhere down the road.