The fMRI data captured during the test showed that the temporoparietal junction – a region of the human brain that plays a key role in redirecting attention – doesn't have an equivalent in the macaque brain. "We didn't see any activity in the temporoparietal junction in the macaques," Patel says. The researchers also found that some brain areas were more active in humans than in macaques during the attention task. Finally, there was more communication between the two brain hemispheres in humans compared with the macaques – a finding that Patel says was very surprising.