Study: Infants process faces long before they recognize other objects

by Max Mcclure
Using a net of electroencephalographic sensors, the researchers noninvasively measured the electrical activity of participants' brains. Credit: Stanford Vision and NeuroDevelopment Lab

(Medical Xpress)—Using brain-monitoring technology, Stanford psychology researchers have discovered that infant brains respond to faces in much the same way as adult brains do, even while the rest of their visual system lags behind.

Any mother will tell you that love staring at . It isn't just parental wishful thinking, either; studies show that babies, even those less than an hour old, tend to stare at face-like images longer than at any other pattern.

But this preference is a little surprising – newborns' visual systems aren't yet fully developed, and infants often have trouble distinguishing between basic shapes. How can they zero in on something as complex as a face?

New research from Professor Anthony Norcia and postdoctoral fellow Faraz Farzin, both of the Stanford Vision and NeuroDevelopment Lab, suggests a physical basis for infants' ogling. At as early as four months, babies' brains already process faces at nearly adult levels, even while other images are still being analyzed in lower levels of the visual system.

The results fit, Farzin pointed out, with the prominent role human faces play in a baby's world.

"If anything's going to develop earlier it's going to be face recognition," she said.

The paper appeared in the online Journal of Vision.

The researchers noninvasively measured generated in the infants' brains with a net of sensors placed over the scalp – a sort of electroencephalographic skullcap.

The sensors were monitoring what are called steady state visual potentials – spikes in brain activity elicited by . By flashing photographs at infants and adults and measuring their at the same steady rhythm – a technique Norcia has pioneered for over three decades – the researchers were able to "ask" the participants' brains what they perceived.

When the experiment is conducted on adults, faces and objects (like a telephone or an apple) light up similar areas of the temporal lobe – a region of the brain devoted to higher-level visual processing.

Infants' neural responses to faces were similar to those of adults, showing activity over a part of the temporal lobe researchers think is devoted to face processing.

Infants were "not yet face experts like adults," Farzin said, "but well on their way."

Objects, on the other hand, lit up a lower-level area of the visual system – a part of the occipital lobe devoted to processing more basic visual features such as contrast or orientation.

The researchers can't yet say, however, whether this early jump on is intrinsic or the result of infants encountering faces over and over again in their daily life.

The context in which babies encounter faces is very different than it is for objects, Norcia pointed out. "When you see a face, you're looking at your mom, you're interacting," he said. "It's associated with a reward."

The findings may also have significance for a class of neurological and neurodevelopmental conditions that cause lifelong struggles with facial recognition. The difficulties are associated with restricted oxygen flow or trauma to the brain shortly after birth or atypical early development of the face-specific brain region.

Related Stories

Infants' peripheral vision blurry

Sep 16, 2010

Our eyes are windows to the world, but what is the visual experience of infants? We know that infant vision tends to be blurrier than adults'. Now researchers from UC Davis, UC Berkeley and Stanford University have discovered ...

Speed limit on babies' vision

Jul 14, 2011

Babies have far less ability to recognize rapidly changing images than adults, according to research from the UC Davis Center for Mind and Brain. The results show that while infants can perceive flicker or movement, they ...

Recommended for you

Memory in silent neurons

18 hours ago

According to a generally-accepted model of synaptic plasticity, a neuron that communicates with others of the same kind emits an electrical impulse as well as activating its synapses transiently. This electrical ...

Why your favourite song takes you down memory lane

Aug 28, 2014

Music triggers different functions of the brain, which helps explain why listening to a song you like might be enjoyable but a favourite song may plunge you into nostalgia, scientists said on Thursday.

Transcranial Magnetic Stimulation of brain boosts memory

Aug 28, 2014

Stimulating a particular region in the brain via non-invasive delivery of electrical current using magnetic pulses, called Transcranial Magnetic Stimulation, improves memory, reports a new Northwestern Medicine ...

User comments