Babies spend most of their time asleep. New technologies are beginning to reveal why.

Babies spend most of their time asleep. New technologies are beginning to reveal why. thumbnail
This article is from The Checkup MIT Technology Review’s weekly newsletter on biotech. Sign up . to receive it in your email every Thursday. I, like many others, don’t get enough sleep. My four-year old likes to wake up at 4 a.m. to chat with me. I’m jealous of my two-year-old, who gets a 12-hour stretch overnight and a two-hour nap in the afternoon. The luxury!

Toddlers need more sleep than adults. My youngest used to sleep even more. It seemed like she was barely awake for the first few months of her life. Scientists are still trying to figure out why babies need so much sleep. But a new tool is beginning to shed some light on this mystery. It could help reveal the brain’s rapidly developing parts.

This is a time when the brain is developing new connections at an incredible rate,” Topun Austin, a consultant neonatologist at the UK’s Cambridge University Hospitals NHS Foundation Trust says. These connections are believed to play a crucial role in helping babies understand the world around them. As babies develop their understanding, many of these connections will be lost. The first weeks of a baby’s life are crucial for laying the foundations for their future.

Sometimes, researchers will put a cap of EEG electrodes on a baby to study electrical brain activity. However, this type of imaging doesn’t provide much spatial resolution. It is difficult to pinpoint which brain regions are active at any given time.

Others have put babies in MRI scanners that measure blood flow in the brain. You’ll be able to see why these hulking machines are not the best place for a baby if you’ve ever had an MRI. They can be noisy and require that the person being scanned remain still.

Austin, Julie Uchitel (a former PhD student at Cambridge, now a Stanford University medical student), and their colleagues have a new approach. The cap has light sources and sensors embedded within it. This is what the team used. These components can be used together to measure blood flow in brain the same way a pulse oximeter is attached to your finger in a doctor’s office.

Similar techniques have been used to study the brain before, but they require the use of a cap with multiple fiber-optic cables coming out of it–not something a newborn is likely to want to sleep in. The new device makes use of recently developed tiles that each contain several light sources and detectors. Austin’s team has fitted 12 of these tiles into a cap suitable for newborns, connected to a computer with a single cable. The resulting system offers an image of the brain “at least 10 times the resolution of the [previous] fiber-optic cable system,” says Austin.

In a recent study in the journal NeuroImage asked parents if they would be able to monitor their babies while they are still in a hospital’s postnatal ward. Austin says, “It’s almost like a swimming cap. The babies seem very happy once it is on.” His team recorded activity from the brains of 28 newborns as they slept.

Babies cycle through two phases of sleep: an active phase, which is accompanied by twitching and grimacing, is followed by a quiet phase, when the baby is very still. The team filmed all babies while their brains were monitored so they could later determine which phase each baby was in.

Later, when Austin and his team analyzed snapshots of the recordings, they noticed differences in the brain during active and quiet sleep. When the babies were more fidgety during active sleep, brain regions in both the left and right halves seemed to fire in the same manner. Austin says this suggests that long, new connections are being formed all over the brain. It seems that there are more short connections within brain regions during quiet sleep.

It’s not clear what this could be, but Austin has an idea. He believes that active sleep is more important to prepare the brain for building a more broad conscious experience. He thinks it’s more important for the brain to recognize another person as a person and not just a series of colors and textures. This requires that different brain regions work together. The shorter connections made during quiet sleep are likely to fine-tune how individual brain regions function. Austin says: “In active sleeping, you’re building a picture. In quiet sleep [you are] refining things .”

We have more information about how healthy newborn brains work so we can help babies who are prematurely born or who suffer from brain damage very early in their lives. Austin hopes to find out more about the effects of each phase on the brain. We might be able, with a better understanding of the brain’s functions, to determine when it is safest for us to wake our baby to feed him.

Austin envisages some kind of traffic light system that could be placed close to a sleeping baby. A green light could indicate that the baby is in a intermediate sleep state and can now be awakened. A green light might signify that the baby is in an intermediate sleep state and can be awakened. However, a red light could indicate that the baby is still asleep as the brain is still working on something.

I’ve tried something similar with my kids. The cloud-shaped toy that is in their room turns green when it’s safe to wake Mummy. The cloud is ignored. Unfortunately, their brains don’t wake up until they are awake.

This kid is screaming like mad. The mom is anxious. The whole thing is stressful.” Rachel Fritts explores just how tricky it is to study babies’ brains in fMRI scanners in this piece from last year.

A fetus can start to hear muffled sounds from 20 weeks’ gestation. The poor quality of these sounds might be essential for early brain development, writes Anne Trafton.

One of the best ways to boost your kids’ brain development is to chat with them, as Anne Trafton finds.

Ever wondered what your brain does to make you think? Lisa Feldman Barrett explains in this piece, originally published in the Mind Issue of our magazine.

Neuroscientists are mapping connections in the brain by barcoding individual brain cells, as Ryan Cross wrote in 2016.

From around the web

China’s covid wave is coming, thanks to the easing of stringent restrictions on a susceptible population. (The Atlantic)

A million people in China are at risk of dying from covid-19, and Beijing is already running out of medical supplies. (Financial Times)

DNA that was frozen for 2 million years has been sequenced. The oldest DNA sequences have been made, involving DNA from ancient fish, plants, and even an animal mastodon. (MIT Technology Review)

A whopping 247 million cases of malaria were thought to have occurred in 2021, according to new figures published by the World Health Organization. The organization estimates that around 619,000 people died from the disease. (WHO)

Sleep trackers promise to score your sleep. But that won’t necessarily solve the problem of insomnia. (The New York Times)

Some of the first data on the effectiveness of vaccines used to protect against mpox (previously known as monkeypox) in the current outbreak are starting to emerge. At one center in Paris, 276 people who had been exposed to the virus were vaccinated within 16 days of exposure. 4% of these people developed an mpox infection. (The New England Journal of Medicine)

Read More