Babies can feel pain before they know what it means

Every parent remembers the first cry of their newborn – a sound that seems to carry both the spark of life and a hint of distress. Does this cry reflect pain? And if so, is that pain anything like what an adult feels?

Pain is not simply a physical sensation. It also involves emotional distress and cognitive evaluation. To feel pain in the way adults understand it, the brain must process it through multiple networks.

A recent study by UCL and King’s College London maps how babies’ brains develop the ability to sense and interpret pain. The work reveals that these abilities do not all appear at once.

The experts scanned 372 preterm and term infants between 26 and 42 weeks postmenstrual age. The brain activity of the babies was compared to adults using MRI data from two massive neuroimaging databases.

“Pain is a complex experience with physical, emotional, and cognitive elements – each part responsible for different aspects of it,” explained lead researcher Professor Lorenzo Fabrizi.

Pain networks develop at different times

Pain involves three networks: sensory-discriminative, affective-motivational, and cognitive-evaluative. These networks connect different brain regions that identify, respond to, and interpret pain.

The research shows that these networks mature at different rates. The sensory-discriminative network develops first; by 34 to 36 weeks, infants can detect the location and intensity of pain.

The affective-motivational network matures between 36 to 38 weeks, enabling emotional responses to painful stimuli.

The cognitive-evaluative network develops last, only after 42 weeks, meaning that even full-term infants lack a complete understanding of pain.

According to the study, sensory connections rapidly strengthen from 34 weeks, affective ones follow, while cognitive links remain sparse even at term.

Pain sensitivity grows fast

The research also shows a strong increase in both the number and strength of brain connections from 26 to 42 weeks. Still, only the oldest infants reached adult-like proportions in any network.

By 38 to 40 weeks, sensory pathways exceeded adult connection strength. Affective pathways also strengthened sharply.

However, cognitive pathways – those tied to conscious thought – were weaker than adult levels in 40 percent of cases. This confirms that infants may feel pain but struggle to understand it.

Preterm babies respond more to pain

A 2023 study had shown that preterm infants do not habituate to repeated painful procedures. The new study explains this with brain development. Preterm babies may lack the cognitive tools to make sense of pain or modulate it.

“Preterm babies may be particularly vulnerable to painful medical procedures during critical stages of brain development… including the role of tailored pain management,” noted Professor Fabrizi.

How pain networks form in a baby’s brain

The sensory network matures earlier due to early development of spinal nociceptive circuits. These help babies sense noxious input quickly.

According to the authors, axonal growth, synaptogenesis, and myelination start in sensory areas before spreading to others.

The affective network, which processes emotional pain, matures later. Connections involving the amygdala and anterior cingulate cortex appear only after 32 weeks.

Cognitive networks, involving the prefrontal cortex, are the last to mature. These support conscious awareness and memory of pain. Some frontal connections are still missing at birth, especially in preterm babies.

Why this matters for neonatal care

This study makes it clear: term infants are not mini-adults in how they feel pain. Their brains are still forming essential networks.

The researchers show that even full-term babies have weaker cognitive pain processing than adults. That means clinical teams must time procedures carefully.

For preterm infants especially, poorly timed painful interventions can have lasting consequences.

The brain’s pain-processing systems continue developing after birth. Full maturation, especially in the cognitive domain, may take months or even years.

Babies feel pain differently from adults

This research shifts how we understand infant pain. Newborns feel it, but they experience it differently. Recognizing this gap between sensory input and cognitive processing is vital.

Caregivers and clinicians must act with this knowledge, protecting newborns during this delicate stage of neural development.

The study is published in the journal Pain.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–