Intraparietal sulcus

The lateral surface of the parietal lobe is cleft by a well-marked furrow, the intraparietal sulcus (IPS) of Turner, which consists of an oblique and a horizontal portion.

The IPS is involved in processing symbolic numerical information. A 2006 study by Jessica Cantlon et. al. concluded The IPS provides the neurobiological platform for nonsymbolic numerical processing in young children, then supports the expanding capacity for higher-math operations in adulthood.

The IPS is also involved in processing the Interprets the intent of others. A 2006 study by Scott Grafton and Antonia Hamilton has found that the IPS was strongly activated when the subject saw another person reach for an object that they want, like a cookie. "We were able to find the part of the brain involved in interpreting the goal of another person, even if no words are spoken," says Hamilton.