Over the past few decades, cognitive scientists have found that small alterations in how people study can accelerate and deepen learning, improving retention and comprehension in a range of subjects, including math, science and foreign languages.
The findings come almost entirely from controlled laboratory experiments of individual students, but they are reliable enough that software developers, government-backed researchers and various other innovators are racing to bring them to classrooms, boardrooms, academies -- every real-world constituency, it seems, except one that could benefit most: people with learning disabilities.
Now, two new studies explore the effectiveness of one common cognitive science technique -- the so-called testing effect -- for people with attention-deficit problems, one of the most commonly diagnosed learning disabilities.
The results were mixed. They hint at the promise of outfoxing learning deficits with cognitive science, experts said, but they also point to the difficulties involved.
The learning techniques developed by cognitive psychologists seem, in some respects, an easy fit for people with attention deficits: breaking up study time into chunks, mixing related material in a session, varying study environments. Each can produce improvements in retention or comprehension, and taken together capture the more scattered spirit of those with attention deficit hyperactivity disorder, especially children.
The testing effect has proved especially reliable for other students, and it is a natural first choice to measure the potential application to ADHD. The principle is straightforward: Once a student is familiar with a topic, testing himself on it deepens the recall of the material more efficiently than restudying.
In one new study, led by Laura Knouse of the University of Richmond, 100 college students, 25 with ADHD, tried to memorize two sets of 48 words. The students studied the word lists in two sessions, watching as the words appeared for a few seconds on a computer screen. In follow-up sessions, they restudied one list and took a free-recall test on the other list. After two days, they came back to the lab and took an exam on all the words. They were given 20 minutes to remember as many as they could.
"We found that you do better when you test yourself, rather than restudy, and that it didn't matter if you had ADHD or not," Knouse said in an interview. On average, the students recalled about 35 percent of the words they had studied twice, and 45 percent of those they studied once and then quizzed themselves on.
The other study found something altogether different. Psychologists at Trinity College in Hartford had 36 students, half with an ADHD diagnosis, study two short science essays, one on sea otters and the other on the sun. The experiment proceeded like the Richmond one: The students then restudied one of the essays in a separate session, and tested themselves on the other essay -- free recall -- typing as much as they remembered reading.
Again, they returned to the lab two days later for a comprehensive exam on both essays. This time, there was no difference in performance for those with ADHD, and only minuscule improvement, on the "pretested" essay, for those without the diagnosis.
"If anything, for the ADHD group, the restudying was a little bit better," said Nicole Dudukovic, the lead author, who is now at the University of Oregon. The likely reason, she said, was that the students with attention deficits did not remember much from the first study session, so the pretesting was a wash.
"We also suspect that there will be some individual differences in how well this technique works, from person to person," Dudukovic added.
And there's the rub, experts said. ADHD, like many mental conditions, manifests as a spectrum of discrete types, some more hyperactive, others more distractible. Then there are the effects of the stimulant medication that many with ADHD take, which neither study addressed.
"Clearly, there's a lot of work to be done," said Gregory Fabiano, a psychologist at the University at Buffalo. "You want to see how these techniques apply not only to different types, but also in different contexts, like community college, occupational training and other settings. But this is a good start."