Tuesday March 31 2009
Autistic people sometimes have difficulties with social interaction
Cartoons "could help spot autism”, BBC News has reported. According to the news service, research now suggests that doctors could pick up autism earlier by observing how a toddler responds to animations. Babies usually start paying attention to movement soon after birth and they pick up information from the cues they see, but children with autism often do not.
Researchers created five simplified 'cartoons', i.e. screen versions of animated children's games, such as 'peek-a-boo' and 'pat-a-cake', featuring sound and dots of light to represent human movement. The screen also displayed some manipulated animations that were upside down and the wrong way around. Researchers played these animations to 21 two-year-olds with autistic-spectrum disorders (ASD), 39 children who were developing normally, and 16 who had developmental problems but were not autistic. Children with autism focused on movement linked to sound regardless of whether the animation was correct or manipulated.
This small study may lead to a new technique for diagnosing ASD. As the researchers say, understanding the processes involved in attention at young ages, and how this is derailed in autism, may become a useful focus of future research.
Where did the story come from?
This research was conducted by Dr Ami Klin and colleagues from the Yale Child Study Center at Yale University School of Medicine in the US. The study was supported by a grant from the National Institutes of Mental Health in the US, Autism Speaks and the Simons Foundation. The study was published as a letter in Nature, the peer-reviewed journal.
What kind of scientific study was this?
This was an experimental study in which the researchers explored how children with autistic spectrum disorder reacted to simplified animations of human movement. This was based on a previous observation that an infant with autism did not recognise these animations of biological motion, but was instead highly sensitive to non-social, physical cues that happened to occur at the same time.
The researchers give some background to the development of motion perception in children, saying that typically developing human infants notice motion in biological things, such as human faces and bodies, within the first days of life, and that this ability is believed to be critical in forming family attachment.
The researchers also say that the nerve pathways for this perception of movement overlap with the regions of the brain involved in appreciating basic social signals (such as facial expression and gaze direction). Paying attention to this biological motion marks the start of how humans understand the intentions of others.
In this study, the researchers wanted to see how well children under two years old paid attention to biological motion, and compared them to children with autism who do not appear to notice this biological motion in the same way. The researchers also wanted to explore what other factors might be affecting autistic children’s visual attention.
They created five sets of “point-light animations” consisting of simple children’s games, such as ‘peek-a-boo’, using live actors and motion-capture technology. This motion-capture process attached points of light to parts of the actor’s body, which were then translated into ‘cartoons’. These cartoons represented figures as a number of moving dots, similar to stick men. Audio recording was included in the motion-capture sessions.
These cartoon point-light animations were presented on one half of a computer screen, together with the audio soundtrack of the actor’s voice. On the other half of the screen, the same animation was presented, but either shown upside-down or played backwards from the end of the sequence until its beginning. Only the single (forward) audio soundtrack was presented to the children.
The researchers selected 21 children with ASD to compare with 39 typical normal toddlers and 16 toddlers who were developmentally delayed but not autistic.
They tested the children for levels of audiovisual synchrony (AVS) in all animations. For example, in a pat-a-cake animation, when the light points hands collide and a clapping sound occurs, an abrupt change in motion coincides with a noise. They measured how well the children followed the change in motion and changes in sound that occurred together.
What were the results of the study?
The researchers show that two-year-olds with ASD did not turn towards the moving figures in time with audio cues. They are also more easily distracted by “non-social” action when watching these displays. These non-social actions were disregarded by the control children, i.e. those without ASD or other developmental delays.
What interpretations did the researchers draw from these results?
The researchers say that this observation has “far-reaching implications” for understanding how the brain develops in people with autism.
What does the NHS Knowledge Service make of this study?
This study of development in children, although small, may point the way towards a new technique for diagnosing autistic-spectrum disorder. Time will tell if this method can be translated into a useful screening tool or lead to new treatments.
It should be noted that this study required a complex scientific assessment of eye movement in children using specialised equipment. A parent would not be able to determine whether their child had autism by observing the way that they watched cartoons on television.