USC Logo Experts Here is a quick tidbit into some novel secrets of the human brain. USC scientists have now discovered a region of the brain that empowers people’s ability to comprehend a scene within a fraction of a second. The study findings may have major implications in the medical world.

According to the authors, the key is to process the interacting objects that comprise a scene more quickly than unrelated objects. The brain’s ability to comprehend whole scene on the fly is believed to help look at objects one by one and slowly add them up. The interaction of objects in a scene supposedly allows the brain to detect those objects faster than if they were not interacting.

In order to find out the ‘where’ of the scene-facilitation effect lies, scientists flashed drawings of pairs of objects for just 1/20 of a second. A number of objects were depicted as interacting, like a hand grasping for a pen, and some were not, with the hand reaching away from the pen. Study subjects had to press a button if a label on the screen matched either one of the two objects, which it did on half of the presentations.

For accurately identifying the responsible region of the brain, participants had to undergo transcranial magnetic stimulation. Under this treatment, electromagnetic currents may alternately zap the two regions of the brain. As a result, the regions go numb for some time and no assistance can be taken from them while performing the task.

On completion of the study, corresponding author Irving Biederman, professor of psychology and computer science at the USC Dornsife College of Letters, Arts and Sciences and colleagues measured how precise subjects were in detecting objects shown as interacting or not interacting when either the lateral occipital cortex or the intraparietal sulcus were zapped. Simply zapping the lateral occipital cortex possibly eliminated the scene-facilitation effect, while zapping the intraparietal sulcus did nothing. In conclusion, it was asserted that identifying objects is a part of an interaction in the lateral occipital cortex.

The study is published in The Journal of Neuroscience.