Individuals with more autistic traits can see finer detail

Results of a research study conducted by Abby Dickinson, Dr Myles Jones and Dr Elizabeth Milne University of Sheffield

Sensory symptoms are now recognised as part of the assessment and diagnosis procedure for autism spectrum condition (ASC), as many people with ASC report being more or less sensitive to auditory, visual, or tactile information. Understanding how perception in ASC varies, and why this might be, provides greater insight into the condition and its cause. 

The current study focused on understanding vision, as ASC is associated with differences in vision, such as processing things in more detail. For example, someone who is processing something in more detail might be better able than most to tell whether a picture frame is straight or tilted. This is an example of orientation discrimination, which we can measure by finding the lowest amount of tilt a person needs to be able to tell the picture frame is straight or not. 

We carried out a study to see whether differences in orientation discrimination were present in individuals who don’t have a diagnosis of ASC, but have a high level of autistic traits. We can measure the level of autistic traits that someone has by getting them to answer a series of questions which ask about different social and communication preferences. Many people believe ASC to be a spectrum condition, with everybody showing a certain level of so-called ‘autistic traits’. If enhanced orientation discrimination is associated with the presence of autistic traits, we would expect to see differences in orientation discrimination between those with low and high levels of autistic traits.

We used a task in which participants had to tell whether black and white lines had been tilted clockwise or anti-clockwise. By varying how much we tilt the lines we can see the lowest angle of tilt a participant needs to be able to tell which way they have rotated. We found that people with a high amount of autistic traits are better at orientation discrimination. This means that individuals who have a high amount of autistic traits can tell if something is tilted when it has been moved much less than a person with a low amount of autistic traits. This suggests that individuals who have a higher amount of autistic traits may be processing visual stimuli in more detail.

We are now carrying out this study in individuals who have an ASC diagnosis, to see if the same enhancements in orientation discrimination are present. 

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