A Belgian study published in the journal Neuron provides first direct evidence that there are specific brain areas involved in the perception of the world in three dimensions . Specifically, the work reveals that the inferotemporal cortex has neurons that specifically perceive convex surfaces (curved outward) and others that detect concave ones. Therefore, thanks to this brain area, we can look at a globe and identify that it is convex and three-dimensional.
In their experiments, the researchers worked with rhesus monkeys who stimulated groups of neurons in this area of the brain with electric shocks as they tried to decide whether a surface was concave or convex. The results showed that, when shocks were applied to neurons firing against convex surfaces, primates tended to choose "convex" in their decision (even if it was wrong). The same was true of concave surfaces and neurons that specifically reacted to them.
"We categorize the shapes of the three-dimensional world around us thanks to neurons specialized in certain structures," conclude researcher Peter Janssen and his colleagues at Neuron .
