This finding, published in the journal Nature Neuroscience, challenges the popular educational approaches designed for ASD individuals that focus on repetition and drills. It has been thought that because those with ASD sometimes acquire a new behavior or skill only in a specific context, and have difficulty transferring that learned skill or information to a new context, repetition can aid the learning process.
“Our conclusion is quite different: breaks in repetition allow the visual system some time to rest and allow autistic individuals to learn efficiently and to then generalize,” says David Heeger, a professor in NYU’s Center for Neural Science and one of the study’s co-authors. “Repeated stimulation leads to sensory adaptation which interferes with learning and makes learning specific to the adapted conditions. Without adaptation, learning is more efficient and can be generalized.”
In the study, high-functioning ASD adults and control participants were trained to find the location of three diagonal bars surrounded by horizontal lines on a computer screen. Both groups were asked to identify the diagonal bars during eight daily practice sessions and their speed and accuracy were measured. The bars stayed in the same location for the first four days and were moved to a second location in the display for days five through eight.
The results showed that for the first four days — with the diagonal bars in the first location — learning was equivalent for the ASD and control groups. However, once the location of the diagonal bars changed, there was a substantial difference. The control group smoothly transitioned to learning the new location and their performance continued to improve. By contrast, the individuals with autism performed poorly when the target location was changed and they were not able to improve their performance, indicating that they received no benefit from initially learning the first location. In addition, they were never able to learn the second location as well as the first, demonstrating an interference in learning that may reflect the consequences of extensive repetition.
“It’s like they showed ‘hyperspecificity’ of learning — their learning became fixed and inflexible — since learning the first location adversely influenced their ability to learn the second instance,” said Hila Harris, the study’s lead author and a doctoral candidate at the Weizmann Institute.
Next, the researchers looked for ways to circumvent the hyperspecificity. With a new group of ASD adults and controls, they ran the exact same experiment, but this time they occasionally inserted “dummy” screens that did not contain any diagonal bars. This time, when the location of the bars changed on the fifth day, the ASD group efficiently learned the new location.
“There have been few systematic investigations into the fundamental mechanisms by which information is acquired by ASD individuals — and into the potential reasons for their restricted, atypical learning,” observes co-author Marlene Behrmann, a professor of neuroscience at Carnegie Mellon University. “This study begins to scratch the surface of the phenomenon.”
The study also included researchers from the University of Pittsburgh and the University of Haifa.
The study was supported by the U.S.-Israel Binational Science Foundation and the Simons Foundation Autism Research Initiative.
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