This weekend, more than 900 teachers, researchers, and other education experts met to share what they know about how we learn. At a session of the Learning & the Brain conference titled “The Web-Connected Generation: How Technology Transforms Their Brains, Teaching and Attention,” we heard a lot about multi-user virtual environments, enhanced reality, the myth of multitasking, and individualized web-based learning. But the tech story that most caught my attention was a slightly older one: reading.
Why do many kids with ADHD “suddenly” start to lag in reading comprehension by the fourth grade? They seem to have acquired the basic skills at the same rate and competence as their peers; they recognize and use phonemes, they can recall words at sight. One part of the reason is that we’ve been assuming that once kids master all the basic language skills they need, fluency just comes naturally, but that doesn’t always seem to be the case. Another is that the act of reading itself is a form of multitasking, and in some ways kids with ADHD have a harder time doing it.
Multi-tasking (or “dual-task performance,” since your brain almost always switches back and forth among tasks) has always been a part of life. Just getting the family out of the house and on its way in the morning is an exercise in ordered chaos, and we usually do it pretty well. But it comes at a cost: We pack a lunch but then forget to take it, and everything seems to take a little longer.
Don’t believe me? Here’s an experiment Hopkins professor and clinician Martha Denckla did with us at a conference over the weekend. Do this out loud (or mumble if you’re going to distract someone):
1. As fast as you can, say out loud the numbers 1 through 10.
2. As fast as you can, say the letters of the alphabet A to J.
3. Now, as fast as you can, alternate the numbers and letters: 1-A, 2-B, etc.
If we were true multitaskers, Case 3 would take us exactly the same time as Case 1 plus Case 2. For most of us in the audience, it took far longer. Why?
Part of the loss was the time it takes to switch back and forth between the tasks, a tiny but measurable sliver, Denckla said. Another contributing factor is automaticity: Most of us are so familiar with our numbers and letters we don’t have to do a lot of processing to recite them (for me, it was so automatic it was hard to stop at J since that’s not a natural break in the rhythm of the “song”). But when you switch, you have to pay more attention, and what started as two beyond-simple tasks, when combined become two more difficult ones.
Dual-processing is necessary to fluent reading; it’s especially obvious in reading out loud. You see a word and decide how to pronounce it; as you are saying it, you are processing the next words in the line; on and on. It helps that the letters and sounds are automatic, and it helps if your working memory is wide enough to store the “on-deck” sounds as you plunge along.
Researchers already knew that kids with ADHD have troubles with working memory; could that explain their troubles with reading comprehension? Not entirely, said Denckla, also a member of the Dana Alliance for Brain Initiatives. “Multitasking to me fits into the realm of attention and executive function,” including initiating tasks, sustaining them, inhibiting possible interference, and switching to the next task and back.
So now, “we’re trying to deconstruct the black box that leads to low processing speed in ADHD,” Denckla said. She showed us some ongoing research from the Center for Study of Reading Development Project III, including work prepared by Joshua Ewen of Hopkins and Kennedy Krieger Institute.
“You can measure a timed response where they have to shift or multitask, and you see that ADHD kids are slower…It seems like an oxymoron, to say that [what we call] hyperactive children are slow, but everything they do is slow and variable,” Denckla said. We all have a central processing bottleneck; “it costs everybody something…you have a greater refractory period, but they have more.”
“Almost every way we test them, children with ADHD have troubles with automaticity,” she said. They seem to lack an efficient method to prepare and respond to something they already know—like sounds that go with letters—so when they are tasked with doing that as well as speaking a string of words out loud, they slow down. And when we require them to sit still (inhibit natural wiggling and jiggling), it may not be an automatic process for them and thus would take more conscious attention, slowing them down a little more. It adds up, and by fourth grade shows up on tests of reading comprehension.
“Kids with ADHD have a higher cost for multitasking; this cost manifests in processing speed. We’ve localized it as slow response speed.” This differs from research by others on kids with autism, which suggests that they are having trouble at the switching point, not in speed of response, Denckla said.
For the majority of people, reading is a skill, automatic; it seems to me I never had to think about it after I learned my letters. But for a significant minority of us, it is a struggle to become fluent in this “old technology.”
Working memory influences processing speed and reading fluency in ADHD. DOI: 10.1080/09297049.2010.532204 - Lisa A. Jacobson, Matthew Ryan, Rebecca B. Martin, Joshua Ewen, Stewart H. Mostofsky, Martha B. Denckla, & E. Mark Mahone; Child Neuropsychology Vol 17, Issue 3, 2011, pages 209-224 (PubMed NIH pdf)
Multiple Task Interference is Greater in Children With ADHD. DOI: 10.1080/87565641.2011.632459 - Joshua B. Ewenab, Jeffrey S. Moher, Balaji M. Lakshmanan, Matthew Ryand, Priya Xavierd, Nathan E. Crone, Martha B. Denckla, Howard Egeth, & E. Mark Mahone; Developmental Neuropsychology Vol 37, Issue 2, 2012, pages 119-133