NYC Gazette

Babies blink, cry, and yawn—and a few weeks into their lives, they might smile. But do these movements indicate that newborns have conscious experiences of perceiving the world around them? Or are these processes happening unconsciously?

In recent years, scientists have paid increasing attention to consciousness—our subjective experience of the mind and the world. They've studied consciousness in adults, in people with mental disorders, and even in animals. However, until recently, consciousness in newborn infants has been poorly understood.

Based on recent studies measuring babies’ brain activity and eye movement, the case for consciousness in newborns is increasingly strong, according to a new article in the journal Neuron by Claudia Passos-Ferreira, assistant professor of bioethics at the NYU School of Global Public Health.

“We still don’t have a final answer, but new evidence has contributed to an increasing consensus that consciousness starts early, in contrast with other theories that claim we need more cognitive development and brain maturation for babies to become conscious,” says Passos-Ferreira.

This new evidence for consciousness relies on methods that creatively measure brain activity in newborns. Infants can’t respond to verbal cues or directions and sleep quite a bit, making their minds difficult to study.

“Neuroscientists often describe the infant brain and behavior as very noisy—it’s difficult to extract information, and what’s going on is not as clear as in adults,” says Passos-Ferreira.

Passos-Ferreira’s new article discusses novel ways scientists gauge whether babies are conscious: measuring brainwave responses to unexpected sounds, using imaging to evaluate the brain’s networks, and tracking eye movements such as blinks and pupil changes to see how babies react to different stimuli. The studies show that cognitive processes related to consciousness may begin functioning in babies earlier than previously thought.

NYU News spoke with Passos-Ferreira about what the latest research reveals about when consciousness emerges in human development.

"My previous work focused on the self and morality and how these things develop," she said. "I realized that there had not been much progress in philosophical discussions about the early stages of when we become conscious. So I moved my research and now I’m focusing on when and how our conscious mind develops."

Regarding challenges faced while studying infant consciousness beyond their "noisy" brains:

"First, babies sleep a lot. Because consciousness requires awakeness, babies need to be awake to be tested," she explained. "Infants have sleep states that are not completely like ours; they fluctuate between 'active sleep,' which is close to being awake, and 'deep sleep.' By only relying on behavior observation, it can be hard to determine whether infants are sleeping or awake."

She also noted difficulties due to lack of verbal communication: "We cannot give a verbal command to a baby—'Raise your hand' or 'Move your mouth' or 'Open your eyes if you hear me'—and expect them to follow."

Discussing methods used by scientists:

"We know that the brain has different networks involved in consciousness," she said. "One network is for external awareness... Another one is for internal awareness... When you’re conscious, there is a reciprocal activation with these two networks."

More advanced imaging techniques revealed well-developed networks even at early stages: "We’re seeing a pattern emerge that confirms...in early stages...the brains of infants...are already working in this reciprocal way with the two networks."

Another study demonstrated similar reactions between adult brains and newborn brains when experiencing something unexpected: “Researchers found that after hearing [a] sequence repeated several times...the infant brain learns it and reacts with surprise if [it] changes.”

On fetal consciousness before birth:

"There is still an open debate about consciousness during pregnancy," she stated. While it is widely believed thalamocortical structures necessary for consciousness develop around 26 weeks of pregnancy: "...even after fetuses develop [these] structures...[they] might not be deploying this capacity because of chemicals...that keep them sedated."

Lastly addressing implications for care:

"I think this is really important for infant care..." She added: "...if we have a better understanding about infants’ conscious minds...we may be able to enhance [relations]."

Understanding when pain perception begins could influence pediatric care practices significantly since recent findings suggest infants feel pain similarly though not identically compared adults: "...20 areas [of] adult brain react [to pain], whereas newborns have 18 areas activated..."