Babies brains’ can follow a beat as soon as they’re born
Two new studies show that infants can categorize some images and sense interruptions in rhythms
Keeping a baby still in a function MRI isn't easy. But that's exactly what researchers attempted to test how babies' brains categorize visual objects.
Courtesy of Cliona O Doherty
For more than a century, psychologists thought that the infant experience was, as the psychologist and philosopher William James famously put it, a “blooming, buzzing confusion.” But new research suggests babies are born with a surprisingly sophisticated neurological toolkit that can organize the visual world into categories and pick out the beat in a song.
In the first of two new studies, neuroscientists managed a rare feat: performing functional MRI (fMRI) scans on more than 100 awake 2-month-old infants to see how their brains categorize visual objects. fMRI requires near-stillness, which makes scanning babies notoriously difficult. While the infants lay in the machines, images of animals, food, household objects and other familiar items appeared above their heads like “an IMAX for babies,” says Cliona O’Doherty, a developmental neuroscientist at Stanford University who conducted the work at Trinity College Dublin.
“MRI is difficult even under ‘ideal’ circumstances when research participants can follow instructions to hold still,” says Scott Johnson, a developmental psychologist at UCLA who was not involved in the study. “Babies can’t take instruction, so these researchers must have the patience of saints.”
The imaging showed that a brain region called the ventral visual cortex, responsible for recognizing what we see, already responded similarly to that of adults, O’Doherty and colleagues report February 2 in Nature Neuroscience. In both adults and 2-month olds, the ventral visual cortex’s activity is distinct for different categories of objects, pushing back against the traditional view that the brain gradually learns to distinguish between categories throughout development.
“These findings argue against a slow, bottom-up development of visual category representations,” says Michael Frank, a cognitive psychologist at Stanford University who was not involved in the research. He notes the study poses a provocative question: Is this structure the result of rapid learning in the first eight weeks after birth, or is it innate?
A second study shows that newborns are capable of yet another impressive cognitive feat even earlier in development. Less than 48 hours after birth, brains of sleeping newborns already follow and anticipate rhythmic patterns in music, researchers report February 5 in PLOS Biology.
Researchers in Hungary played piano pieces by Bach to almost 50 newborns while recording their brain activity using EEG, electroencephalography. In addition to the original Bach recordings, the team also played altered versions of each piece that sometimes scrambled the rhythm or the melody. The team then searched for patterns of surprise in the neural recordings using a computational model, which would imply that the babies learned the structure of the music and had their expectations broken.
An altered rhythm did elicit neural surprise, whereas a scrambled melody went unnoticed by the infants’ brains, the results showed. Baby brains can keep a beat, but they can’t follow a tune.
This makes some sense. “In the womb, the rhythmic features are already very predominant in the listening environment of the baby,” says Roberta Bianco, a neuroscientist now at the University of Pisa in Italy who led the study. “You have the [heartbeat] of the mom, the walking of the mom and rhythmic information of any sort passes through.” The amniotic fluid, however, muffles specific pitches, so fetuses get less exposure to melodic patterns while in the womb.
“I think it is important to also keep in mind that the ability to neurally track periodicities in music does not necessarily equate to rich musical beat or meter perception,” says Erin Hannon, a psychologist at the University of Nevada, Las Vegas, who was not involved in the study. “Many studies suggest it takes children a long time to get good at dancing or moving in time with music, or to correctly match a drum or metronome to music.”
In both studies, brain activity is the focus, but the implications for early cognition or behavior remain unclear. The field of newborn neuroscience still has its whole life ahead of it.
