Infant Attention and Brain Activity Shaped

Three new studies reveal how instability in a baby's environment shapes attention, brain activity, and emotional regulation. The research, led by UC Irvine assistant professor of psychology Denise Werchan and published in August 2026, separates different kinds of adversity, focusing on unpredictability rather than just hardship.

Werchan was struck by how much early learning research comes from controlled lab studies, which are very different from the rich, noisy world babies actually grow up in. She became convinced that understanding real-world experience is key. "I became convinced that if we want to understand how learning really happens in early childhood, we need to understand what babies actually experience in their everyday lives," Werchan said.

Prediction Machines

At the heart of the studies is the idea that babies are "prediction machines." Werchan explained that a baby constantly tracks patterns to learn about the world. When the environment is predictable, they form expectations that support attention, learning, and emotional control.

In a study published in Infant Behavior and Development, researchers followed 160 infants aged 3 to 12 months. They used a webcam-based eye-tracking tool to measure gaze from home video. Infants from households where access to food, utilities, and housing fluctuated unpredictably tended to shift their gaze more frequently during a visual attention task. This was true even after accounting for overall economic circumstances.

Werchan thinks babies may adjust how they pay attention based on their world. In an unpredictable environment, shifting attention widely may be a useful way to gather information. She acknowledged the distinction matters. "A behavior that looks like a deficit in one setting may actually be a useful response to another," she said.

Caregiving Predictability and Brain Activity

Another study, published in Developmental Cognitive Neuroscience, zoomed in on caregiver behavior. Researchers coded transitions between a caregiver's auditory, visual, and tactile signals during play with 104 three-month-olds. Babies whose caregivers shifted between behaviors in less predictable sequences showed reduced frontal brain activity, a neural marker for attention. They also showed lower heart rate variability, a measure of nervous system flexibility.

Werchan explained the difference using an analogy. "I think of it as the difference between a familiar nursery song and jazz improvisation," she said. A predictable interaction gives the baby a clearer sense of what might come next. These differences appeared at just three months old. "I don't think there is such a thing as 'too early,'" Werchan said.

A Possible Buffer in Breast Milk

The third study, published in Developmental Psychobiology, examined a possible buffer against adversity. It looked at 81 mother-infant pairs. The research found that a naturally occurring neurosteroid in breast milk, allopregnanolone, appeared to weaken the link between a mother's stress and depression and her baby's ability to regulate emotion and behavior. A synthetic version of this compound is used to treat postpartum depression.

Werchan was emphatic that the finding should not pressure mothers to breastfeed. "This is early, preliminary science about one possible biological pathway. It is not a set of instructions," she said. The bigger message is that a mother's mental health matters. "Postpartum depression and anxiety are common and treatable, and struggling doesn't mean you're doing something wrong."

Across all studies, Werchan highlights the difference between hardship and instability. "A lower-resourced family with a steady routine and dependable day-to-day life may be giving a baby something important that a higher-resourced but unpredictable household isn't," she said. She argues that stable housing, dependable childcare, and adequate parental leave are part of the developmental environment. "Supporting caregivers is one of the most direct ways we can support healthy child development," Werchan concluded.