Coloured Filters Enhance the Visual Perception of Social Cues In Children with Autism

Background: Social deficits in Autism Spectrum Disorders (ASD) have been repeatedly described. For example, avoidance of eye contact and inefficient use of eye gaze are early social features of autism. Reports in the literature consistently note that children with ASD often inspect objects (e.g. hands, moving objects) in an unusual way, using their peripheral vision. These sensory behaviours are reminiscent of those characterised in other literature as visual stress, though possibly more extreme.

Objectives: To date, it is unknown whether perceptual abnormalities underlie the failure to observe subtle facial expressions in children with autism. Coloured filters have previously been found to reduce visual distortion of text in children with ASD and to improve perception more generally. The aim of the current study was to assess whether coloured filters could also benefit social cognition in children with ASD.

Methods: 15 high functioning children with a diagnosis of Autism Spectrum Disorders (mean 13 years of age) and 15 typically developing children (mean age 12 years 4 months) matched for age, gender and non-verbal IQ undertook the “Rate of Reading Test” and ”Mind in the eye” task with and without coloured overlays.  The first test required them to read a passage of randomly ordered common words aloud for one minute. In the second test the children were shown monochrome photographs of the eye region of various faces and were asked to judge which emotion was being expressed in the eyes. 

Results: Consistent with previous studies 80% of children with ASD were found to read faster with the use of a coloured overlay. Importantly, a similar proportion of children with ASD  (73%) were also found to improve their perception of the emotion when the photograph was covered by a coloured overlay. The improvement was significantly greater than in controls, who showed no significant effect of using an overlay on either the Rate of Reading Test or the Mind in the Eye Task. 

Conclusions: The facial expression of emotions has profound implications for social understanding and deficits in social perception are among the core characteristics needed for a diagnosis of autism.  Little is known about the underlying reasons for such deficits but the current findings suggest that a perceptual impairment may contribute.