A look inside children's minds: New study shows how 3- and 4-year-olds retain what they see around them

June 27, 2013
Researchers at the University of Iowa have found that children have a limit to what they can see and remember at a given time, known as visual working memory. In tests, the researchers found that 3-year-olds can hold a maximum of 1.3 objects in visual working memory, while 4-year-olds reach capacity at 1.8 objects. Adults hit the ceiling at 3 to 4 objects. Credit: Sondra Cue, University of Iowa

(Medical Xpress)—When young children gaze intently at something or furrow their brows in concentration, you know their minds are busily at work. But you're never entirely sure what they're thinking.

Now you can get an inside look. Psychologists led by the University of Iowa for the first time have peered inside the brain with optical to quantify how much 3- and 4-year-old children are grasping when they survey what's around them and to learn what areas of the brain are in play. The study looks at "visual working memory," a core cognitive function in which we stitch together what we see at any given point in time to help focus attention. In a series of object-matching tests, the researchers found that 3-year-olds can hold a maximum of 1.3 objects in visual working memory, while 4-year-olds reach capacity at 1.8 objects. By comparison, adults max out at 3 to 4 objects, according to prior studies.

"This is literally the first look into a 3 and 4-year-old's brain in action in this particular working memory task," says John Spencer, psychology professor at the UI and corresponding author of the paper, which appears in the journal NeuroImage.

The research is important, because visual working has been linked to a variety of childhood disorders, including attention-deficit/hyperactivity disorder (ADHD), autism, as well as affecting children born prematurely. The goal is to use the new brain imaging technique to detect these disorders before they manifest themselves in children's behavior later on.

"At a young age, children may behave the same," notes Spencer, who's also affiliated with the Delta Center and whose department is part of the College of Liberal Arts and Sciences, "but if you can distinguish these problems in the brain, then it's possible to intervene early and get children on a more standard trajectory."

Plenty of research has gone into better understanding visual working memory in children and adults. Those prior studies divined neural networks in action using function magnetic resonance imaging (fMRI). That worked great for adults, but not so much with children,­ especially young ones, whose jerky movements threw the machine's readings off kilter. So, Spencer and his team turned to functional near-infrared spectroscopy (fNIRS), which has been around since the 1960s but has never been used to look at working memory in children as young as three years of age.

"It's not a scary environment," says Spencer of the fNIRS. "No tube, no loud noises. You just have to wear a cap."

Like fMRI, fNIRS records neural activity by measuring the difference in oxygenated blood concentrations anywhere in the brain. You've likely seen similar technology when a nurse puts your finger in a clip to check your circulation. In the brain, when a region is activated, neurons fire like mad, gobbling up oxygen provided in the blood. Those neurons need another shipment of oxygen-rich blood to arrive to keep going. The fNIRS measures the contrast between oxygen-rich and oxygen-deprived blood to gauge which area of the brain is going full tilt at a point in time.

The researchers outfitted the youngsters with colorful, comfortable ski hats in which fiber optic wires had been woven. The children played a computer game in which they were shown a card with one to three objects of different shapes for two seconds. After a pause of a second, the children were shown a card with either the same or different shapes. They responded whether they had seen a match.

The tests revealed novel insights. First, neural activity in the right frontal cortex was an important barometer of higher visual working memory capacity in both age groups. This could help clinicians evaluate children's visual working memory at a younger age than before, and work with those whose capacity falls below the norm, the researchers say.

Secondly, 4-year olds showed a greater use than 3-year olds of the parietal cortex, located in both hemispheres below the crown of the head and which is believed to guide spatial attention.

"This suggests that improvements in performance are accompanied by increases in the neural response," adds Aaron Buss, a UI graduate student in psychology and the first author on the paper. "Further work will be needed to explain exactly how the neural response increases—either through changes in local tuning, or through changes in long range connectivity, or some combination."

Explore further: Brain activity in sleep may impact emotional disturbances in children with ADHD

Related Stories

Brain activity in sleep may impact emotional disturbances in children with ADHD

May 29, 2013
Sleep consolidates emotional memories in healthy children but not in children with attention-deficit hyperactivity disorder (ADHD), according to research published May 29 in the open access journal PLOS ONE by Alexander Prehn-Kristensen ...

Early brain responses to words predict developmental outcomes in children with autism

May 29, 2013
The pattern of brain responses to words in 2-year-old children with autism spectrum disorder predicted the youngsters' linguistic, cognitive and adaptive skills at ages 4 and 6, according to a new study.

Babies show visual consciousness at five months

April 19, 2013
(Medical Xpress)—A new study by scientists in France and Denmark has identified a neurological marker in the brain of babies as young as five months that is associated with visual consciousness, or the ability to process ...

Autism in children affects not only social abilities, but also broad range of sensory and motor skills

June 25, 2013
A group of investigators from San Diego State University's Brain Development Imaging Laboratory are shedding a new light on the effects of autism on the brain.

Brain imaging study eliminates differences in visual function as a cause of dyslexia

June 6, 2013
A new brain imaging study of dyslexia shows that differences in the visual system do not cause the disorder, but instead are likely a consequence. The findings, published today in the journal Neuron, provide important insights ...

Team finds age-related changes in how autism affects the brain

March 13, 2013
Newly released findings from Bradley Hospital published in the Journal of the American Academy of Child & Adolescent Psychiatry have found that autism spectrum disorders (ASD) affect the brain activity of children and adults ...

Recommended for you

The neural codes for body movements

July 21, 2017
A small patch of neurons in the brain can encode the movements of many body parts, according to researchers in the laboratory of Caltech's Richard Andersen, James G. Boswell Professor of Neuroscience, Tianqiao and Chrissy ...

Faulty support cells disrupt communication in brains of people with schizophrenia

July 20, 2017
New research has identified the culprit behind the wiring problems in the brains of people with schizophrenia. When researchers transplanted human brain cells generated from individuals diagnosed with childhood-onset schizophrenia ...

Scientists discover combined sensory map for heat, humidity in fly brain

July 20, 2017
Northwestern University neuroscientists now can visualize how fruit flies sense and process humidity and temperature together through a "sensory map" within their brains, according to new research.

Scientists reveal how patterns of brain activity direct specific body movements

July 20, 2017
New research by Columbia scientists offers fresh insight into how the brain tells the body to move, from simple behaviors like walking, to trained movements that may take years to master. The discovery in mice advances knowledge ...

Team traces masculinization in mice to estrogen receptor in inhibitory neurons

July 20, 2017
Researchers at Cold Spring Harbor Laboratory (CSHL) have opened a black box in the brain whose contents explain one of the remarkable yet mysterious facts of life.

Speech language therapy delivered through the Internet leads to similar improvements as in-person treatment

July 20, 2017
Telerehabilitation helps healthcare professionals reach more patients in need, but some worry it doesn't offer the same quality of care as in-person treatment. This isn't the case, according to recent research by Baycrest.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.