THREE-year-old Sophie is sitting at a low table, trying to build a house out of large plastic bricks, as a nearby adult gives gentle encouragement. It could be a scene from any nursery school, but for the incongruous apparatus that Sophie wears: a snugly fitting black cap studded with sensors and sprouting multiple thick, black wires. It looks slightly sinister, but the harmless cap is letting researchers do something that has never been done before: peer inside the brains of active toddlers.
Sophie is a participant at the ToddlerLab, a state-of-the-art facility at Birkbeck University of London that is investigating child development. The wires from the cap she is wearing run from the top of her head into two small recording units tucked into her backpack. This apparatus enables the team to image her brain as she moves around, while a pair of motion-capture gloves and 16 discreet cameras evenly spaced around the ceiling record the movement of each of her fingers down to one-hundredth of a second.
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Brain imaging has taught us a lot in the past two decades about the structure and function of the brain in sickness and in health, but most approaches have limitations. The standard magnetic resonance imaging (MRI) device is a huge noisy machine that people have to lie inside, quiet and still, for up to an hour at a time.
This means MRI can鈥檛 be used easily on young children or to study any activities that require moving around 鈥� which are significant chunks of human existence.
Now the technology being used at the ToddlerLab, called functional near-infrared spectroscopy or fNIRS, is changing that. With equipment small enough to sit inside a lightweight cap, it beams infrared light through the skull, so that it is scattered into nearby receivers, also sited in the cap.
鈥淭his technology is giving us the first looks at children鈥檚 brains when they are acting naturally鈥�
The amount of light that is absorbed depends on how much oxygenated blood it passes through, which gives an indication of how often neurons are firing in those regions of the brain. In other words, it reveals how hard your brain cells are working, says Lisanne Schr枚er at Birkbeck. 鈥淚t鈥檚 giving us the first looks at children鈥檚 brains when they are acting naturally.鈥�
That isn鈥檛 to say that the work always goes smoothly. 鈥淭oddlers are not the easiest group to work with,鈥� says Schr枚er. Sometimes her subjects decide they don鈥檛 want to wear the special 鈥渟cientist鈥檚 hat鈥�, for instance. 鈥淚f they say 鈥榥o鈥�, that means no.鈥�
Some of the children who visit today are shy and cling to a parent鈥檚 legs 鈥� so getting down on the floor and blowing bubbles into the air is all part of a day鈥檚 work for the neuroscientist team.
Another child, Finn, seems to hold no fears, but is keener to build a tall tower than the house requested. 鈥淓very session is different,鈥� says Schr枚er.
The project is investigating how we learn to plan and achieve goals by breaking them down into smaller sub-goals, by comparing children who are 3 and 5 years old. Once the children are happy wearing the cap, they are asked to build a simple house shown in a video, which means they need to first build each wall, then put the roof on top.
Using the motion-capture gloves, the team has previously found that when carrying out sub-goals 鈥� such as reaching for a brick 鈥� the child鈥檚 non-dominant hand freezes for a few seconds. 鈥淭his suggests they are focusing on executing the sub-goal,鈥� says Schr枚er.
But planning seems to take place at a different point. The current study indicates that it is when children are between sub-goals that brain activity rises in their prefrontal cortex, the part of the brain that is involved in planning, perhaps because they are selecting their next task. At least, this is the case for those children who complete the house.
Longer-term, a better understanding of brain development could help children who may develop atypically, such as those with autism or attention deficit hyperactivity disorder (ADHD), says team member Paola Pinti.
The technology has other uses beyond studying children. The use of wireless recorders with the infrared brain imaging is enabling researchers to examine adults walking around in the real world, talking to others, or in the workplace. 鈥淚t opens up enormous opportunities,鈥� says Schr枚er. 鈥淚t鈥檚 a whole new field.鈥�
