At Science Magazine, science writer Kelly Servick reports on the recent Infant Consciousness Conference, which addressed the comparatively new question of when unborn children experience consciousness:

“Fetal consciousness would have been a less central topic at a meeting like this a few years ago,” says Claudia Passos-Ferreira, a bioethicist at NYU who co-organized the gathering. The conversation has implications for how best to care for premature infants, she says, and intersects with thorny issues such as abortion. “Whatever you claim about this, there are some moral implications.”

“Consciousness before birth? Imaging studies explore the possibility,” March 10, 2025

It’s no reflection on the organizers or participants that the conference bogged down on topics like “How to define consciousness,” also known as the “Hard Problem of Consciousness.”

Further complicating the picture, the nature of consciousness could be different for infants than adults, researchers noted at the meeting. And it may emerge gradually versus all at once, on different timescales for different individuals. “Explore the possibility”

Almost certainly, that’s true. During the entire period from conception to about one year after birth, most children sleep most of the time. Before birth, children have very limited access to sight and hearing, which are critical for the sort of learning that situates our mental states. In the first few months after birth, they must learn what they are seeing and hearing from a position of almost no information. Meanwhile, they have very limited access to the language older humans use to understand and describe these sights and sounds.

The truly remarkable thing is that they show the amount of consciousness that they do, as quickly as they do.

Cortex? Thalamus? Cerebellum?

Servick explores a number of interesting hypotheses, for example that the connections between the thalamus (sensory and motor information) and the cortex (information processing) are crucial for consciousness: “Studies of fetal brains show the foundations of that link are not in place until about 24 weeks of development.”

It would be helpful to know the outcome of cases where a person’s connections are found to be weak. I raise this question because, researching brain questions for The Immortal Mind (June 3, 2025), I came across a number of examples of people who were missing various brain parts, who were not affected as drastically as predicted and in some cases not much at all. Tying consciousness to specific brain parts is prone to error, as the book’s first author, neurosurgeon Michael Egnor, has often pointed out.

The brain does not function like a machine. Many different parts may be involved in various cognitive functions, including parts we did not expect, like the cerebellum.

Servick acknowledges this issue: “But whether those structures are sufficient for consciousness isn’t clear, so investigators are finding creative ways to search for possible markers of consciousness in brain activity.”

While the research she outlines is valuable for what it may tell us about the needs of prematurely born infants, it can’t escape the fundamental dilemma that consciousness is like trying to look into and out of a window at the same time.

Animal studies can’t help much here

The problem of knowing whether a preborn child of any age is conscious is much more difficult than, say, knowing whether a dog is conscious. We know that he is conscious because we can see, hear, and understand the way he acts and reacts. The fact that he lacks the power of reason certainly doesn’t prevent him from being conscious.

Philosopher Thomas Nagel provided a helpful approach to the question of animal consciousness some decades ago in an influential essay, “What is it like to be a bat?” His point was that if there is something that it “is like” to be a bat, then there is some sense in which the bat is conscious. If there is something that it “is like” to be a dog — and it seems that there is — the dog is conscious.

Of course, we can reverse that assumption too. If we can reasonably conclude that there is nothing that it “is like” to be a sand dollar or a mushroom, then these entities are probably not conscious. We still cannot know that for sure but Nagel’s approach enables a more reasonable guess.

When we consider prenatal humans, the problem is more difficult. We’ve all been there. But none of us remember what that was like. We don’t remember our first birthdays either, and probably not our second ones. But our amnesia doesn’t mean that we weren’t conscious during any of these periods.

Worse, we find it hard to interpret the prenatal experience. When a dog is whining and scratching at the door, we can interpret the urgency he is feeling. But when a child is kicking vigorously inside the uterus, it’s much harder to guess what’s happening or why.

If documented experiences with terminal lucidity and paradoxical lucidity at the other end of the spectrum of human life — extreme old age — are any guide, we should be cautious about concluding that children lack consciousness at a specific point before birth.