Imagine you had never seen a dog before. To introduce you to the idea of dogs, your friend shows you pictures of huskies, but no other dogs. If you then saw a Chihuahua, would you recognize it as a dog? The ability to generalize learning—knowing that a husky is part of a larger category ‘dog’—is critical to the learning process. New research finds that generalization is difficult for people with autism spectrum disorder (ASD). An international research team investigated how well repetition works as a learning method for ASD, demonstrating that people with ASD struggle to generalize what they learn. That is, after seeing 100 pictures of huskies, they would not recognize a Chihuahua as a dog. In fact, the study finds that learning through repetition can harm future learning for people with ASD.
For the study, adults with high-functioning ASD and adults without ASD were trained to find the location of symbols on a computer screen. In eight daily practice sessions, the researchers measured the participants’ speed and accuracy in identifying the symbols. For the first four sessions, the symbols appeared in the same place every time. For sessions five through eight, the symbols appeared in a different location. This allowed the researchers to establish how well people with ASD learn a task and transfer their knowledge to a new, but similar task.
The ASD and control groups had equivalent learning for the first four days of the study. However, there were substantial learning differences in days five through eight. While the control group smoothly transitioned to learning the symbols’ new location, the group with ASD performed poorly. The ASD group was not able to improve their performance during the second half of the study and were never able to learn the new location as well as they had learned the original location of the symbols. The findings indicate that the people with ASD did not receive any benefit from the first half of the training. Moreover, extensive repetition may harm the learning process and limit their ability to generalize information.
The researchers conducted a second round of the experiment with a new group of participants. They completed the same learning task with a small difference. The researchers inserted some screens without the target symbols into the task. When the location of the symbols changed on day five of the study, the participants with ASD were able to efficiently learn the new location.
“Our conclusion is that breaks in repetition allow the visual system to rest and allow autistic individuals to learn efficiently and then to generalize. 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,” stated David Heeger of New York University.
This research is published in the journal Nature Neuroscience.
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