MONTREAL — A new study offers a unique glimpse into the mind of autistic people, suggesting they perceive symmetry better than those who are not autistic.

While most people might look at a butterfly and admire its general beauty, for instance, an autistic person might focus on the fact the left wing is a mirror image of the right wing.

Armando Bertone thinks this difference in perception is linked to the well-known symptoms of autism -- such as fixation on specific objects.

The director of the Universite de Montreal-affiliated Perceptual Neuroscience Laboratory for Autism and Development, Bertone recently published his research findings in the peer-reviewed journal PLoS one.

"A lot of these autistic behaviours are very much related to sensory processing and how persons with autism seemingly process information differently than we do," Bertone said in a recent interview.

"I think we have to understand how autistic persons perceive their world, and we have to use their strengths maximally."

Autism is a neural development disorder characterized by atypical social interactions, restricted interests and repetitive behaviours.

There is a wide spectrum of autism and the symptoms vary, depending on the severity. Some common symptoms include a reduced ability to recognize emotion in faces, rigid adherence to routine and a fascination with spinning objects.

Bertone's research group found that, as with people who are not autistic, symmetry across a vertical axis was the easiest to perceive. An example of this would be the two sides of a human face.

At the same time, he found that people with autism have a heightened sensitivity to symmetry in general -- whether it is vertical, horizontal or diagonal -- as compared to non-autistic individuals.

"Overall, autistic people's sensitivity to symmetry is better than non-autistics'," he said.

He thinks the difference is rooted in the ability of autistic people to isolate detailed, local information, while still processing global information.

In his research paper Bertone describes this as seeing the forest and the trees -- rather than just the forest or just the trees.

Symmetry may stand out to an autistic person because symmetry has a structure to it. Imagine your face and draw a vertical line down the centre; one eye is the same distance from the line as the other eye.

"Kids with autism seem to like very systematic changes, structure," said Bertone. "And this symmetry is a nice visual example of this in that it's a very structured-type information."

Bertone is currently studying cause and effect: is it an increased perception of structure that leads to someone's preference for structured behavioural routines, or vice versa?