News The latest developments in autism research.

Sight may mix with sound in autism brains

by  /  13 May 2016
Sound sensing: Instead of shutting down, a visual brain region becomes more active in people with autism when they hear a tone.

© / Imgorthand

The findings from the conference report below were published 20 May 2016 in Autism Research1.

People with autism may use visual areas of the brain to process sounds, which could help explain why they have trouble with this task. Researchers presented the unpublished findings yesterday at the 2016 International Meeting for Autism Research in Baltimore.

The researchers also found that people with autism have slightly more difficulty than controls quickly distinguishing a high note from a low one.

Together, the findings suggest that people with autism cannot readily distinguish between two tones because they recruit the wrong sensory region in the brain for the task. Alternatively, they may be recruiting visual regions to compensate for weak activity in the brain regions that process sound, says R. Joanne Jao Keehn, a postdoctoral fellow in Ralph-Axel Müller’s lab at San Diego State University, who presented the findings.

Jao Keehn and her colleagues performed functional magnetic resonance imaging on 16 children and teenagers with autism, aged 8 to 18 years, and 16 controls of similar age and intelligence quotient. While in the scanner, the children heard a sequence of 36 tones — which lasted for two seconds each — some high-pitched and others low-pitched.

They then watched a screen displaying a series of rectangles containing a black circle in either the top or the bottom half. For both experiments, the children were told to press one button to indicate that the stimulus was ‘high,’ and another if it was ‘low.’ Interspersed with the tones and rectangles were neutral stimuli: Either two seconds of silence or an empty rectangle.

Seeing sound:

The children with autism correctly chose the pitch of the tone about 83 percent of the time, compared with 93 percent for controls. By contrast, both groups performed well, in the mid-90 percent range, on the visual task.

The researchers then looked at activity in the visual cortex when the children heard the tones, compared with the silent periods. As expected, the visual cortex shut down in the typical individuals when they listened to the sounds.

By contrast, this region became more active in the participants with autism when the tones were played. A direct comparison of the two groups revealed that the difference in activity is localized to a part of the visual cortex called the left lingual gyrus.

This sensory crossover tracks with autism severity, as measured by the Autism Diagnostic Observation Schedule: The participants with higher scores on this test were more likely than those with lower scores to have active visual brain regions when detecting sounds.

The finding suggests that people with autism have unusual sensory processing even during basic tasks, says Jao Keehn. The results may help to explain why these individuals often experience unusual sensory sensitivities.

For more reports from the 2016 International Meeting for Autism Research, please click here.

  1. Jao Keehn R.J. et al. Autism Res. Epub ahead of print (2016) PubMed

5 responses to “Sight may mix with sound in autism brains”

  1. shannonrosa says:

    I’m surprised there aren’t any comments here — the Spectrum team (and the researchers) might be interested in the lively discussion about this article on Thinking Person’s Guide to Autism Facebook — and that most of the comments are from autistic people:

    • Claire Cameron says:

      Thank you for sharing that thread here, Shannon!

      • Ethyl says:

        You have no idea how exciting this is…Thomas West wrote “In the Mind’s Eye” and “Thinking LIke Einstein” He is severely Dyslexic. He comes to the conclusion that both Dyslexics and Autistics often are visual thinkers, and it is more that than “disabilities” that hamper them in a world where 85% of us think in words.

        I used Catherine Maurice’s developmental word curriculum in Behavioral Intervention for Young Children with Autism (I did NOT use ABA tenets in the same book) to present language visually/kinesthetically to my son. His verbal IQ is 126 now, it was about 50 at age 4.

    • Ethyl says:

      Too cool…The fact that there is such discussion on it surely shows a nerve has been touched. I’ll just leave it at that.

  2. Megan M says:

    I’m surprised that there was no mention in this article of the common co-occurrence of autism and synesthesia. Presumably the use of parts of the brain associated with one sense to process input from another sense is related to the phenomena described here.

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