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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Lords of the Jungle ... But Why?
19 February 2002 (All day)
Stare into the intelligent eyes of a gorilla long enough, and you may start to wonder just what it is that sets us apart from our hairy cousins. Researchers long believed the answer lies in a patch of brain called the frontal cortex, which seemed to be proportionally larger in humans than in other primates. But a new comparative study of primate brains--the most comprehensive of its type to date--finds that our frontal cortex isn't any bigger than that of the great apes.
The frontal cortex functions as the executive office of the brain. It plays a key role in abstract thought and language and enables us to plan and control our actions. Nearly 100 years ago, scientists reported that humans had an enlarged frontal cortex compared to other primates. Unfortunately, these studies, which were based on postmortem examinations of brains, compared humans only to the lesser apes, such as gibbons and monkeys. Our closest primate relatives, the great apes, were not included in these studies.
The new study examines the size of frontal cortex in great apes, including gorillas, chimps, orangutans, and bonobos. Anthropologist Katerina Semendeferi and her team at the University of California, San Diego, used magnetic resonance imaging to compare the brains of 10 humans and 24 other primates. In the March issue of Nature Neuroscience, the researchers report that the frontal cortex makes up about 36% of total brain volume in both humans and great apes. In lesser apes, the percentage is only about 30%. The new research suggests to Semendeferi that humans don't lord it over the jungle primates on the basis of an enlarged frontal cortex alone.
One substantial difference is that humans brains are three times larger overall, notes Todd Preuss, a cognitive neuroscientist at the University of Louisiana, Lafayette. He says that researchers must now recognize that regions of the human brain besides the frontal cortex have also expanded. These regions probably include the parietal and temporal lobes, which are the principal sources of information the frontal lobes act upon, Preuss says.