14 DAY TRIAL // Determining how the brain interprets gravity is essential for figuring out how humans interpret the stability of objects they see. A new study has recently demonstrated, for example, that we are better judges of other objects' stability when we are upright, rather than when lying on the side.
Instinctively, we learn during childhood that objects tend to fall off a surface when their center of gravity passes the edge of that surface. In most cases, the center of gravity is located around the center of an object, but some may have this center located elsewhere.
In either case, the brain does a fairly good job at predicting when something will fall. However, this perception of gravity is influenced by some interesting factors, such as the position of the observer's body.
Regardless of the fact that the human brain can interpret this law of physics intuitively, it gets more efficient at it when the person making the observations is upright. A new study finds that laying on the side makes people less accurate in interpreting the effects of gravity.
The new investigation was carried out by experts with the Max Planck Institute for Biological Cybernetics in Tübingen, Germany. The team published its results in the latest issue of the peer-reviewed scientific journal PLoS ONE.
“The force of gravity is not sensed directly. It is the indirect effects of gravity that are detected,” explains postdoctoral neuroscientist Michael Barnett-Cowan, He is also the MPI motion perception study leader, AlphaGalileo reports.
The new research is deeply founded in history. Around 1850, physicist Hermann Aubert was the first to investigate the different perceptions we have on gravity depending on the position of the body.
“Since Aubert we now know that the brain combines visual and vestibular information to determine gravity's direction relative to an internal representation of our body's orientation,” Barnett-Cowan says.
“We wondered whether objects are perceived as stable relative to this biased perceived direction of gravity rather than gravity's true direction,” he goes on to add.
“We might expect the brain to depend primarily on visual heuristics and assumptions about an object when assessing whether it will fall or not,” explains University of Giessen assistant professor of psychology Roland Fleming.
“Surprisingly, however, we find that observers’ judgments of object stability are biased towards the tilt of the body,” he concludes.