Innate categories

30/08/2009 by admin.

Science Daily reported on a paper, ‘Category-specific Organization in the Human Brain Does Not Require Visual Experience’, by B. Mahon and others. (here) The neural pathway called the ventral stream does a quick visual object categorization process (animals, faces, non-living objects etc). But are the categories the product of visual experience and are they inborn?

The human brain distinctly separates the handling of images of living things from images of non-living things, processing each image type in a different area of the brain. For years, many scientists have assumed the brain segregated visual information in this manner to optimize processing the images themselves, but new research shows that even in people who have been blind since birth the brain still separates the concepts of living and non-living objects.

The research…implies that the brain categorizes objects based on the different types of subsequent consideration they demand—such as whether an object is edible, or is a landmark on the way home, or is a predator to run from. They are not categorized entirely by their appearance.

“If both sighted people and people with blindness (from birth) process the same ideas in the same parts of the brain, then it follows that visual experience is not necessary in order for those aspects of brain organization to develop,” says Mahon, “We think this means significant parts of the brain are innately structured around a few domains of knowledge that were critical in humans’ evolutionary history.”

“When we looked at the MRI scans, it was pretty clear that blind people and sighted people were dividing up living and non-living processing in the same way,” says Mahon. “We think these findings strongly encourage the view that the human brain’s organization innately anticipates the different types of computations that must be carried out for different types of objects.”

Mahon thinks it’s possible that other parts of the human brain are innately structured around categories of knowledge that may have been important in human evolution. For instance, he says, facial expressions need a specific kind of processing linked to understanding emotions, whereas a landmark needs to be processed in conjunction with a sense of spatial awareness. The brain might choose to process these things in different areas of the brain because those areas have strong connections to other processing centers specializing in emotion or spatial awareness, says Mahon.

Posted in Uncategorized | 1 Comment »