Like the human brain, the orca brain contains von Economo neurons
: rare, specialised cells that relate to empathy, communication, intuition and social intelligence.
And inside, autopsies showed that brain region was packed with unusual large, spindly neurons - a special and little understood type called von Economo neurons
thought to play a role in social processing and awareness.
The researchers found that, in addition to a thicker and larger cingulate cortex, SuperAgers had 90% fewer neurofibrillary tangles of the type observed in Alzheimer's disease and increased density of von Economo neurons
related to social intelligence.
An earlier study saw no signs of the cells, called von Economo neurons, in macaques.
After many additional tests, he and his colleagues concluded that the cells, though smaller and sparser than their human counterparts, were indeed the elusive von Economo neurons.
One reason for this assumption is that, initially, von Economo neurons were found exclusively in big-brained animals with complex social lives: people, great apes, elephants, whales and dolphins, for instance.
In people, von Economo neurons are located in the anterior insula and anterior cingulate cortex, hubs in the brain for empathy and self-awareness.
In the macaque, the location of the von Economo neurons suggests they may handle a more basic kind of bodily awareness.