The human brain can recognize thousands of different objects, but neuroscientists have long grappled with how the brain organizes object representation — in other words, how the brain perceives and identifies different objects. Now researchers at MIT’s Computer Science and Artificial Intelligence Lab (CSAIL) and Department of Brain and Cognitive Sciences have discovered that the brain organizes objects based on their physical size, with a specific region of the brain reserved for recognizing large objects and another reserved for small objects. As part of their study, they took 3D scans of brain activity during experiments in which participants were asked to look at images of big and small objects or visualize items of differing size. By evaluating the scans, the researchers found that there are distinct regions of the brain that respond to big objects and small objects.
By looking at the arrangement of the responses, they found a systematic organization of big to small object responses across the brain’s cerebral cortex. Large objects, they learned, are processed in the parahippocampal region of the brain, an area located by the hippocampus, which is also responsible for navigating through spaces and for processing the location of different places, like the beach or a building. Small objects are handled in the inferior temporal region of the brain, near regions that are active when the brain has to manipulate tools like a hammer or a screwdriver. The work could have major implications for the field of robotics, in particular in developing techniques for how robots deal with different objects, from grasping a pen to sitting in a chair.