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Researchers in the Yale Department of Psychology measured activation in babies’ frontal lobes during attention exercises for the first time by using fMRI — a challenging technology to use with infants.

In a study published on March 16, the authors used fMRI — an imaging technique that detects blood responses to brain activation — to measure brain activity when infants paid attention to shapes on a screen. According to Cameron Ellis, a researcher in the lab of psychology professor Nicholas Turk-Browne and first author on the study, their lab is one of few in the world that performs fMRI in awake babies, as it is challenging to keep them in the scanner. According to Turk-Browne, before this study, there were only three published papers on the use of fMRI in awake infants. The authors found activation in the frontal lobe, an area usually assumed to be too immature in babies to be used in attention tasks.

“The research that we have done has shown that [the brain] may not be doing the exact same thing in babies and an adult and that’s what’s really exciting to me,” Tristan Yates, another author of the study, said. “When you take an adult-centric position might be missing some functions that are there.”

According to Yates, for a long time, scientists considered babies’ frontal lobes to be immature. This is because infants do not seem to have a lot of self-control, a trait that is typically associated with frontal lobe activation in the adult brain. However, she highlighted how the developing child’s brain could be using the frontal lobe for different purposes than older individuals’ brains.

Yates explained that through behavioral tasks, which measure changes in behavior and are the standard practice in the field of child psychology, there is no way to determine what brain areas are activated. Scanning babies’ brains is a challenge, according to Ellis, but the team was able to overcome this obstacle using different techniques to keep the infants calm.

“The mother or father of the infant is always within arm’s reach at any one time,” Ellis explained. The infants also lie in a “really comfortable bed” where they are not constrained in any way, unlike in typical adult fMRIs.

According to the authors, one of the main motivations of the study was uncovering the many unknown processes that the infant brain uses in visual perception and attention. Ellis explained that while it has been extensively proven that babies can attend to stimuli from a very young age, there is almost no knowledge of what brain areas are recruited during this process.

Turk-Browne explained that many aspects of cognition, such as memory retention, cognitive control and decision-making are usually thought to develop slowly over a long period of time. Since these processes are associated with the frontal lobe, the common understanding in the field of psychology was the area’s development also spanned infancy and researchers would not observe frontal lobe activation in infants.

“We adopted the perspective that [the frontal lobe] might play an important role in infants even if this role differs from, or evolves into, other functions later in development when the child is faced with different cognitive needs,” Turk-Browne wrote in an email to the News.

One of the goals of the study, Ellis said, was to “disentangle” the neural processes involved in goal-directed attention versus stimulus-driven attention. The former is a person’s ability to keep their attention focused on a task, while the latter happens when a stimulus from the environment grabs their attention.

Ellis explained that in adults, attention tasks are more likely to involve a mix of goal-directed and stimulus-driven attention. He explained that since the babies in the study were between three and 12 months of age, most of them did not show evidence of goal-directed attention. This fact enabled the researchers to focus simply on stimulus-driven attention.

According to Ellis, this study is part of a series of investigations that he has been working on that involve the imaging of infants’ brain activity. These studies look into cognitive functions such as learning, memory and visual capacities. He explained that there are other ongoing studies, including longitudinal studies, that will evaluate how brain function progresses over time in infants.

“The next steps for the attention project are understanding more goal directed attention and socially oriented attention,” Yates said. “There’s a lot of untapped questions about how infants’ brains work that we’re trying to investigate with our techniques and we’re excited to see where they go.”

The Turk-Browne Lab is located within the Department of Psychology at Sheffield-Sterling-Strathcona Hall.

Beatriz Horta | beatriz.horta@yale.edu