The way we walk
6 June 2006
How do we tell a cowboy's quintessential swagger from a supermodel's slinky sashay? New research reveals that our brains adapt to the subtleties of male and female walking style. Antenna investigates...
This research was published in Nature Neuroscience on 21 May 2006.
Image: Freefoto.com
Scientists at the Salk Institute in California studied how our brains decipher gender using the visual cues that make male and female walking styles - gaits - distinctive.
'Differences in body shape mean women tend to sway at the hips when they walk, while men move more at the shoulders,' explains brain expert Heather Jordan.
Heather Jordan, brain expert, the Salk Institute, California
The researchers were surprised to find that our brains interpret these gait cues using only single nerve cells, or neurons, specialised for the job. They also discovered that these neurons adapt to become maximally sensitive to changes in walking style.
This is a drawing of what a typical neuron looks like.
Image:istockphoto.com
How did they find out?
The researchers used motion capture to convert the movement of real people into computer-generated 3D virtual human figures - the same technique that lets animators create lifelike 'people' in computer games.
Image: Heather Jordan
Next they manipulated these virtual figures to create short movie clips of typical male, female and ambiguous 'point-light-walkers' - removing all the figures' detail to leave only a few moving spots of light. Then they asked volunteers to watch the films and to decide which gender they were seeing.
Can you tell the difference between male and female walkers? The answer is that the male walker is on the right.
Image: Heather Jordan
What were the results?
The volunteers were more likely to decide an ambiguous 'point-light-walker' was female if they'd seen a male figure first. The effect happened vice versa too.
For the scientists, this was a sure sign that individual brain neurons were recognising male and female walkers. And that these neurons were becoming adapted to recognise small changes in gait cues.
But why is this important?
'Until now, we scientists have been unable to put our finger on how the human brain represents abstract concepts like gender. Our experiments suggest that if gender can be represented using a single neuron then other high-level social information could be too.
'Eventually this could give us new insights into understanding social behaviours and then possibly disorders of social behaviour like autism.' Heather Jordan, the Salk Institute, California