Friday, January 27, 2012

Science in Society - Learning without remembering: Brain lab goes to school

 At New Roads School, children's natural ability to spot patterns is being harnessed for learning <i>(Image: Michal Czerwonka/NYT/Redux/Eyvine)</i>
At New Roads School, children's natural ability to spot patterns is being harnessed for learning (Image: Michal Czerwonka/NYT/Redux/Eyvine)

Insights from brain science are finally coming into the classroom with a method based on seeing patterns

SUN, sea and showbiz are what Santa Monica is best known for - from Baywatch to Terminator 2, hundreds of TV shows and movies have been filmed on its beach and streets. But if Philip Kellman and Joe Wise have their way, this southern Californian city will soon have a fresh claim to fame, as the testing ground for a new way of teaching - one that seeks to work with the brain's natural propensity to learn, rather than against it.
You may have heard rumours that brain science is poised to revolutionise teaching. Unfortunately, translating lab findings into methods that work in the classroom has proved problematic. It is here that Kellman and Wise may have stolen a march.
Kellman, a psychologist at the University of California, Los Angeles, works on "perceptual learning" - harnessing the brain's formidable abilities in pattern recognition to teach complex skills and concepts. Wise is a veteran physics teacher who believes conventional schooling often "gets in the way" of what kids can achieve. Together, they aim to discover whether perceptual learning can help free up students' stifled abilities.
The independent New Roads School in Santa Monica is a fitting location for this educational experiment. Not just a hothouse for the already privileged, it uses money from foundations and wealthy individuals to provide financial assistance to half of its students. Some commute for 2 hours from the tough neighbourhoods of South Central Los Angeles. Selection is by interview, not test results, and minorities are in the majority. As I walk through its corridors, there is a tangible buzz about the place.
Kellman and his colleagues have been testing their perceptual learning software here for almost a decade, and last year Wise started to integrate it into the school's regular curriculum. Judging from the views of his students, the approach has made a promising start. "It's like learning how to extract what is key," says 18-year-old Wynn Haimer. "You're able to see patterns, and see that all of these problems are one and the same."
Haimer is referring to a perceptual learning program based around the equation for a straight-line graph: y = mx + b. The usual approach to teaching this equation is to draw the graph, give the equation and then explain that b (or c in the UK) marks where the line crosses the y axis, and that m represents the slope of the line. But even students who think they understand the concept often don't get the significance of what they have been told. They may plug the right numbers into the equation when shown a similar graph, for example, but they often can't identify when a written description of a problem can be solved using the equation.
Perceptual learning, by contrast, does not depend upon explanations of the underlying concepts. Instead, the program used to teach the straight-line equation may flash up a graph and ask which of three alternative written descriptions conveys the same information. Or it may show an equation and ask which of three graphs it describes. After each selection, students are told whether they were right or wrong, and the key elements that define the correct match are highlighted in different colours (see diagram).
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At first, the students may have to guess. But as they progress they attain "mastery" levels and, from time to time, are shown what percentage of answers they got right and how long they are taking, on average, to respond. This feedback seems to tap into the psyche of the video game generation. "It's just fun," says Christopher Allen, another member of the class who found himself trying to answer as quickly as he could. "At the end, the amount of time it took was about a quarter of what it was originally."
Most importantly, as students learned the patterns they gained a deeper understanding without having to make a conscious effort to memorise anything. "It takes on new meaning," says Haimer. "There's nothing to forget, because there's nothing to remember."
This is exactly the point, says Kellman. Perceptual learning exploits the brain's phenomenal ability to detect patterns in a mass of information, a skill that comes naturally to everyone but reaches its peak in people with expertise who can manage mind-boggling tasks. Chess grandmasters, for example, come to the board with a different approach to a chess-playing computer; instead of calculating the outcomes of millions of possible future moves, they see how the game may develop from patterns they have experienced previously. Likewise, air traffic controllers can instantly spot two planes on a collision course on a busy radar screen, and experienced accountants can quickly pick out salient information from sprawling financial spreadsheets. "Perceptual learning is how they get there," says Kellman.
If perceptual learning is such a natural and powerful force, why hasn't it been applied to education before? The main obstacle, Kellman thinks, is that most research into the process has concentrated on low-level distinctions such as how the visual cortex learns to detect subtle differences in the orientation of two lines. If anything, the conventional wisdom among people interested in the cognitive science of education is that the brain's ability to detect patterns gets in the way when trying to learn higher-level concepts. Some critics even say that efforts to apply perceptual learning in the classroom are founded in "folk psychology".
Undeterred, Kellman says the trick is to design software to reinforce patterns that teach the concepts involved correctly. In the case of the line-graph program, the evidence suggests he has got it right. Experiments run at New Roads show that learning via this program can boost scores on conventional pencil-and-paper tests. Teens given a couple of 40-minute sessions with the program doubled their percentage of correct answers - easily beating the modest gains in a control group who simply practised with more of the pencil-and-paper examples (Topics in Cognitive Science, vol 2, p 285).
But New Roads, with its small classes and highly motivated students, is not a typical school. Neither is Joe Wise your average teacher. As well as teaching physics here, he heads the education and public outreach team for NASA's Dawn mission to the asteroid belt. There is evidence of his extracurricular activities on the floor of his office: a scanning tunnelling microscope capable of studying surfaces at the atomic level, which was built by a team of high-school students he got to work in a lab at the University of California, Los Angeles, one summer. "Joe is really five people," jokes Kellman.
Can perceptual learning work in more "normal" school environments? It seems so. Kellman's collaborator, Christine Massey of the University of Pennsylvania, Philadelphia, has obtained similar results in the city's school system. In one experiment, children aged between 11 and 13 who worked with a program designed to teach fractions not only scored much better on tests immediately after the training, but retained these gains when retested five months later.
Perceptual learning could have a role wherever there are patterns, structures or rules to be taken on board. Kellman has already had success with programs teaching the energies and angles of molecular bonds for chemistry undergraduates. Other possible applications include learning the rules of grammar, or how to read music. However, the move from carefully controlled experiments to regular educational practice is not all plain sailing. Wise recalls talking to one girl who was inexplicably struggling. "I said: 'Do you see the pattern?' She said: 'Yes, but I thought that was cheating.'"
For people who are used to being told exactly how to approach a problem and taking tests in which it is possible to obtain full marks, the rapid-fire trial-and-error approach of perceptual learning can be disconcerting. This becomes clear when talking to a group of New Roads's 11- and 12-year-olds who are just starting to use the fractions program, in which they must "slice" a rectangle into equal pieces and then "clone" one of these pieces to try to generate the correct answer. It has been shown to be an effective way of teaching improper fractions, where the numerator is larger than the denominator, but the kids don't like it much. As they grumble about the program, concerns about being judged on their mistakes bubble to the surface. Sanna Legan, who likes to help her classmates, is annoyed that when she did so, the program timed out and marked her wrong.
Perhaps they will think differently as their "mastery" begins to grow. That was the experience of the older pupils, who initially found Wise's class bamboozling as he presented different ways of solving physics problems. "We all started the class kind of hating Joe," says Allen, much to the amusement of his classmates. "But at the end of the year I began to realise that I learned so much in his class, compared to any other."
The verdict from New Roads's broader experiment with perceptual learning won't be in for a while. Established teachers who have seen other approaches come and go tend to be wary, but Wise is slowly getting his colleagues on board. The aim is not to replace conventional explanations of concepts but to make them easier to grasp, he says. Working out how best to integrate the approach into lessons is the next step. "Maybe doing the perceptual learning module first is good. Maybe you get all of the declarative explanation first," says Kellman.
Whatever the outcome, some benefits are already apparent. Allen found himself using the program in the evenings, above and beyond the work he was assigned. "Instead of watching TV, I was learning," he says. When teenagers take on extra work because they are having fun, something must be going right.

Train your brain

What makes a good learner? Ask teachers, and words like "discipline", "flexibility" and "self-control" keep cropping up. These all depend on "executive functions" - cognitive systems including attention and working memory that organise our thinking and keep us focused.
Studies hint that physical exercise, training in martial arts, and curricula that encourage children to regulate their behaviour and think reflectively can boost executive functions. But the most extensive research has been on the role of "brain-training" software, in particular a package called Cogmed developed by Torkel Klingberg of the Karolinska Institute in Stockholm, Sweden. Cogmed is a computer game that trains working memory with tasks that become progressively more difficult. In 2005, Klingberg's team showed that it could improve performance in children with attention-deficit hyperactivity disorder (Journal of the American Academy of Child and Adolescent Psychiatry, vol 44, p 177). Since then it has helped a variety of children with poor working memory.

Beating the bullies

By putting children in functional MRI scanners, a team led by Abigail Baird of Vassar College in Poughkeepsie, New York, hopes to reduce bullying, which, among its many negative impacts, can be a huge drain on educational achievement.
Baird studies "relational aggression" in teenage girls, which usually involves hurtful gossip and ostracism rather than physical violence. She found that girls who had experienced less of this insidious form of bullying have more activity in parts of their prefrontal cortex when asked to determine the emotions expressed on the faces of unfamiliar girls (Social Neuroscience, vol 5, p 519).
Baird suspects that girls with better social cognition skills are more resilient to relational aggression and therefore tend not to be targeted by bullies. The brain regions that lit up in the resilient girls are involved with executive functions including attention and working memory, suggesting that techniques to boost these abilities (see "Train your brain") might also minimise the disruption caused by bullies.
However, Baird thinks the biggest gains will come from ensuring that children's days include time for unstructured interaction with their peers. "There really is no substitute for interacting with humans when it comes to learning how to interact with humans," she says.

Degrees of dyslexia

Diagnosing children with dyslexia is one thing, but working out who will learn to compensate for their reading difficulties and who will continue to struggle used to be impossible. Now brain scans are changing that.
Fumiko Hoeft of Stanford University in California and her colleagues studied children with dyslexia averaging 14 years of age using fMRI and diffusion tensor imaging, which can reveal the connections between brain areas.
The researchers found that those children with greater activity in their right prefrontal cortex during a reading task, and with denser and better organised connections into this region, had made stronger progress with reading when tested two-and-a-half years later (Proceedings of the National Academy of Sciences, vol 108, p 361).
In the future, the researchers hope that brain scans will help reveal why some children with dyslexia struggle to compensate - and perhaps also suggest methods to help.

Trade-off or win-win?

Does learning one skill interfere with acquiring another? That is a crucial question for those trying to find out how best to use the brain's cognitive real estate. They used to wonder, for instance, whether children who grow up bilingual are at an educational disadvantage. Now we know that bilingual children actually have superior abilities in selective attention, which is attributed to the cognitive flexibility that comes from regularly processing information in two languages.
Nevertheless, education may involve some cognitive trade-offs. A team led by Stanislas Dehaene at the French medical research agency INSERM in Gif-sur-Yvette studied adults who learned to read in childhood, in later life or not at all. They found literacy interferes with the brain's activation when processing images of faces (Science, vol 330, p 1359). No one is suggesting that children shouldn't learn to read so they don't impair their facial recognition skills. But responding to faces is important, so working out how to minimise the disruption could be useful.

Peter Aldhous is New Scientist's San Francisco bureau chief

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