SEPTEMBER 29, 2014 – BOYS WITH HIGH-FUNCTIONING autism were found to be significantly faster at a key task of grammar abilities – producing past tenses for regular verbs – than were boys without autism, in a new study by Georgetown researchers.
Because autism is often characterized by language and communication deficits, the study results show a surprising strength in language, says Michael Ullman, PhD, director of the Brain and Language Laboratory at Georgetown University Medical Center, and senior author on the study. The results are published in the November issue of Research in Autism Spectrum Disorders.
“We had not expected this interesting finding,” Ullman says. “It makes us wonder whether some children with autism might also show related strengths, as yet unrecognized.”
Matthew Walenski of Northwestern University, the first author on the study, adds that the study is “consistent with an emerging way of thinking that some disorders, especially those that occur during development, provide strengths as well as weaknesses.”
In the study, 20 high-functioning boys with autism ages 7 to 13 and a control group of 25 typically developing boys were asked to produce past tenses of verbs. Because autism is much more prevalent in boys than in girls, only boys were tested in the study.
The boys with autism were significantly faster than the control group at producing regular past tenses, such as “step-stepped” or made-up verbs like “plag-plagged.” But they were no faster than the control group at producing irregular past tenses, such as “sing-sang” or the made-up “spling-splang.”
“This is a simple and elegant test of the basic building blocks of language,” Ullman says. “Processing regular past tenses reflects our grammatical abilities that are critical for understanding and producing sentences, while irregular forms are simply stored in our mental dictionary alongside words like “’cat.’”
The results suggest that boys with high-functioning autism may demonstrate speedier processing of grammar.
“These grammatical abilities likely depend on the procedural memory system – implicit memory that we use to learn and perform cognitive and motor skills such as playing video games and driving,” Ullman adds. “We don’t know if the increased speed we saw in processing regular past tenses in children with high-functioning autism affects other aspect of procedural memory, but we are excited to explore that possibility.”
The third study co-author is Dr. Stewart Mostofsky of the Kennedy Krieger Institute, where the subjects were recruited and tested.
Support for the research was provided by the National Science Foundation (SBR-9905273), the National Institutes of Health (R01 MH58189, R01 HD049347, R01 NS048527), and by research grants from the National Alliance for Autism Research, the Mabel Flory Trust, and the Simons Foundation.