Men and women use different parts of their brains when forming emotionally charged memories, a new study has shown.
In two rounds of tests involving horror movie clips, 11 men and 11 women had their brain activity scanned by positron emission tomography.
The first involved particularly disturbing scenes from the gruesome Faces of Death and similar films, while the second contained excerpts designed to be comparable in quality but emotionally neutral.
Larry Cahill, assistant professor of neurobiology and behaviour at the University of California, Irvine, said the results were striking.
The study focused on the amygdala, a part of the brain that plays a key role in forming memories of emotional events.
In the men, the horrifying scenes triggered an enhanced response in amygdala on the right side of the brain.
In women, the same stimulus produced a response on the left-hand side.
"Men and women watching Jaws may experience similar emotional reactions and make similar memories, but they seem to be doing it in very different ways," said Cahill.
"Popular folklore since the time of Plato has noticed differences in emotional responses of men and women, yet until now it has not really been addressed by the neuroscience community."
Nevertheless, when the test subjects self-assessed the emotional content of each clip, there was no difference between the sexes. This suggests the difference is specifically memory related rather than in any immediate emotional reaction.
The study, published in the journal Neurobiology of Learning and Memory , adds to a growing body of research that is revealing neurological differences between the sexes in such diverse areas as language, navigational ability and defensiveness.
Cahill said his research also indicated that the differences in brain function extended beyond the amygdala, which is intimately linked to the hormonal system.