Studies looking at overall brain size have found that some people with autism have larger brains and others have smaller brains. Studies on structure have found some areas bigger in people with autism, and some smaller. Studies on the ratio between grey matter and white matter have found less white matter in people with autism (white matter helps signals to transmit across the brain, so it implies slower signalling).
Studies on connections in the brain have found fewer long-range connections and more short-range connections.
Not all studies show these results, and because we know that every person with autism is different, it is likely that the differences in brain structure will vary across the population.
Theory of Mind is the ability to identify thoughts and emotions, understand that others may have different thoughts and emotions to them and predict what they are going to do next.
Executive Function is a term which is used to describe functions such as planning, working memory, inhibition, impulse control and mental flexibility. Problems with executive function are not unique to autism and not all people with autism have difficulties with executive function.
Central Coherence refers to detail-focussed processing which is sometimes seen in autism. For example, some people can identify the pitch of a champagne cork popping, or the brand of a vacuum cleaner by the sound alone. It is sometimes described as an “inability to see the bigger picture”