New Research: The Origin of a Key Symptom of Autism

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One of the many big problems that children suffering from autism face is the inability to understand/grasp the social and emotional aspects of human speech. This issue fuels the problems they have in social situations and in regulating their own emotions and understanding the emotions and intentions of others. However, new research from Stanford University School of Medicine has implicated poor connectivity in certain brain regions as a cause for this problem. Weak brain connectivity in areas that are tailored to respond to voices can mean that the experience of speech is not pleasurable.

Dr Daniel Abrams, lead author of this study, points out that the human voice is a very important sound – it holds a lot of meaning, and contexts, as well as giving a lot of extremely valuable emotional information. With insensitivity to the human voice being a key issue in autism, this study has given important evidence as to the origins of this problem. Abrams et al used children with a high functioning form of autism, that had problems with holding conversations and reading emotional cues regardless of a normal IQ and reading skills.

Through fMRI scanning they could compare the activity in these specific brain areas with the activity shown in 19 typically developing children. It has been shown in previous research that adults with autism have low voice-selective cortex (VSC) activity in response to speech, but this new study shows that there are weak connections between the voice-selective cortex and other brain regions in people suffering from autism.

Their participants with a high functioning form of autism had very weak connections between the VSC and the nucleus accumbens and the ventral tegmental area. These two brain areas in particular release dopamine in response to rewards in the brain, showing how the response to human speech could be less pleasurable than in those who do not suffer from autism. They also found a weak connection between the VSC on the right side of the brain and the amygdala – which is central to processing emotion. As this side of the VSC specialises in detecting vocal cues (such as pitch and intonation) this weak link proves a very valuable discovery in the origins of autism.

A positive correlation was also discovered between the two; the weaker the connections in the brain, the more severe communication problems they face. It was even possible for the researchers to predict the scores on the verbal portion of the standard test of autism severity based on the degree of their connection impairment. So, it is clear that research provides us some very useful information about the origin of communication issues in children suffering from autism.

As well as this, this study helps to validate some of the existing therapies used for autism. For example, the pivotal-response training tries to increase the social use of language in children who speak words but don’t usually talk to others. It attempts to motivate children in a natural way to use speech, language and other forms of social interaction. And from this researchers can now focus on investigating whether these connections in the brain are strengthened by therapies such as this.

So, it is clear to see that this research has provided useful evidence as to the origins of this key symptom of autism. Who knows where we can go from here?

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Written by: Philippa Berry
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