A quarterly publication of the Autism Research Institute
Fall, 2017 | Number 4, Volume 31
Individuals with synesthesia exhibit two characteristics—increased sensory sensitivity and enhanced attention to detail—that are also common in autism, according to a new study.
In synesthesia, people experience “crossed” reactions to stimuli. For instance, people with grapheme-color synesthesia (GCS) perceive letters or numbers to have colors, while people with spatial-sequence synesthesia (SSS) perceive sequential concepts such as numbers and calendar dates as existing in physical space—for instance, to their right or floating over their heads. While synesthesia and autism co-occur more often than expected by chance, the vast majority of people with synesthesia do not have autism.
In the first part of the new study, Jamie Ward and colleagues used the Glasgow Sensory Questionnaire (GSQ) and the Autism Spectrum Quotient (ASQ) to evaluate sensory sensitivity and autistic traits in 182 synesthetes. All of the participants either had GCS or SSS, but not both. A number of them also had other forms of synesthesia.
The researchers found that compared to controls, synesthetes had elevated scores for sensory sensitivity on the GSQ as well as elevated scores on the “attention to detail” subscale on the AQ. (While they exhibited elevations on other AQ subscales, the researchers say the effect size was small.) Moreover, the researchers detected a “dose-like” effect: The more forms of synesthesia participants had, the higher their scores for sensory sensitivity and attention to detail were.
In the second study, which involved 56 participants, the researchers looked for evidence that the enhanced sensory sensitivity and attention to detail seen in individuals with synesthesia translate into superior cognitive abilities. In two tests, one involving spotting embedded figures and the other involving detecting changes in a scene, the researchers found that individuals with synesthesia outperformed controls.
They comment, “Synesthetes appear to occupy an important cognitive niche: They gain many of the benefits linked to autism without necessarily incurring the impairments (but with an elevated risk of doing so).” They speculate that “synesthesia has the potential to become an important model for understanding the symptoms and neurodevelopment of autism.”
“An autistic-like profile of attention and perception in synaesthesia,” Jamie Ward, Paris Brown, Jasmine Sherwood, and Julia Simner, Cortex, October 25, 2017 (epub prior to print publication). Address: Jamie Ward, School of Psychology, University of Sussex, Falmer, Brighton, BN1 9QH, UK, [email protected].
