Shape perception in brain develops by itself

DESPITE minimal exposure to the regular geometric objects found in developed countries, African tribal people perceive shapes as well as westerners, according to a new study.
The findings, recently published online in Psychological Science, suggested that the brain’s ability to understand shapes develops without the influence of immersion in simple, manufactured objects.
“In terms of perceiving the world ... either genetics or the natural world will give you the right type of experiences,” said lead author Irving Biederman, an expert on perception who holds a named chair in neuroscience at the University of Southern California’s College of Letters, Arts and Sciences.
Biederman and his team specifically measured subjects’ sensitivity to “non-accidental” properties of objects, such as whether they have straight or curved edges.
A theory of shape recognition developed by Biederman holds that the brain is more sensitive to non-accidental properties — which stay the same as an object rotates in space — than to metric properties, such as degree of curvature, that do appear to vary with orientation.
In one experiment, subjects were asked to identify which of two geometric objects was an exact match to a sample object. The one that didn’t match differed either in a non-accidental or metric property.
The researchers found that Western college students and members of the semi-nomadic Himba tribe of northwestern Namibia, a rural area bordering Angola, both showed greater sensitivity to non-accidental properties.
The findings have an incidental implication: Parents can probably toss the beloved shape sorter on the large heap of educational toys toddlers do not really need.