How people with autism miss the big picture

“A picture is worth a thousand words” may sum up how people with autism see the world.

Brains scans of people with the condition show that they place excessive reliance on the parietal cortex, which analyses images, even when interpreting sentences free of any imagery. In other people, the image centre appears to be active only when the sentences contain imagery.The results agree with anecdotal reports that people with autism are fixated on imagery but struggle to interpret words and language. They frequently excel at recording visual detail, but overlook the bigger picture and the context that comes with it.Researchers led by Marcel Just of Carnegie Mellon University in Pittsburgh, Pennsylvania, scanned volunteers’ brains while they were deciding if certain statements were true or false. Some of the statements relied on analysis of language alone, while others could only be understood by considering the imagery they conjured up. “The number 8, when rotated 90 degrees, looks like a pair of spectacles”, for instance, needs both arithmetic interpretation and visualisation of the rotated number.Just says that the observed over-reliance on the parietal cortex might have arisen to compensate for poor brain connections to the prefrontal cortex, which interprets language. “That makes it difficult to understand complex language and to understand the intentions of other people,” he says.(Source: University of Pittsburgh: July 2006).