The human brain is equipped with a crucial structure at birth. Over nine months, approximately 100 billion neurons develop from a tiny 3-millimeter “neural tube,” establishing the foundation for the entire central nervous system.

This impressive neuronal count is enhanced by around 100 trillion connections that form between them, akin to subway lines connecting station hubs in a bustling city. “It’s intelligently designed to enhance efficiency,” states developmental neuroscientist Moriah Thomasson from New York University.

As birth approaches, the brain’s structure starts resembling that of an adult: the fetal connectome shares 61% of the same functional organization found in adults. “It’s astonishing,” Thomasson remarks, though the fetal brain shouldn’t be mistaken for a smaller version of an adult’s brain. While some species, like foals, can walk or feed shortly after birth, humans undergo extended childhoods, developing into highly social and dependent beings.

“The incomplete nature of our brains allows our environments to shape them,” explains philosopher of mind Timothy Bain from Monash University in Australia. “As a result of evolution, if we were born in a Russian-speaking country, it would be problematic if we inherently spoke Swahili.”

Birth triggers significant changes in the brain. “It’s a transformative experience,” states Thomasson. The transition from the buoyancy of the womb to the weight of gravity, fluctuating temperatures, and a flood of new visual stimuli creates a profound learning environment. Accordingly, insulating layers known as myelin sheaths are rapidly formed, enhancing connections across the nervous system and refining specialized brain networks. “These pruning processes become increasingly intense,” notes Thomasson, “Essentially locking in vital connections.”

As a result, our ability to navigate the world grows more sophisticated, with higher cognitive skills building upon foundational abilities. For instance, we begin by distinguishing between objects before learning to track their movements and recognize faces and emotions. “Tracking emotions early on is critical for understanding others’ mental states,” Bain notes.

Advancements in brain scanning technology allow researchers to study the formation and connectivity of brain networks in both adults and fetuses. However, determining the implications for experiential development remains complex. Observed patterns of brain activity and behavior in utero imply that elements of consciousness may exist within the fetus. “It’s possible that fragments of prenatal experience exist, and the capacity for consciousness is likely present,” Bain states, yet he believes that true consciousness may not emerge until the infant confronts the challenges of the external world.

Despite the connection between consciousness and brain biology being clearer, philosophical debates continue regarding the relationship between thought and consciousness. “Can one think without being conscious? Can there be consciousness without thought?” questions philosopher of consciousness Philip Goff of Durham University, UK. Bain suggests that thinking is more about our capability to engage with the world. For example, a few months after birth, infants can controllably move objects above their heads. “Perhaps the first thought a baby experiences is the joy of fulfilling an intention or the recognition of a failed one,” he ponders.

The notion that thought and consciousness only emerge post-birth seems intuitive. However, cognitive scientist Anna Chaunika, from the University of Lisbon, Portugal, cautions against this adult-centered bias. We often view experience through a lens rooted in brain function and assume that thoughts comprise intricate concepts. Nevertheless, research indicates that sensory experiences integrate into the basic sense of self through behaviors established during early pregnancy, as noted by Chaunika. This process of interaction and learning remains crucial for survival. The evolutionary origins of gut neurons and our olfactory system’s rapid specialization for fetal development highlight this interconnectedness. “Being precedes knowledge,” she concludes.

Ultimately, the fetus’s existence centers around its mother. “In the womb, we are inherently in communion with other beings,” notes Chianica, citing studies showing that newborns exhibit different crying patterns based on their mothers’ linguistic backgrounds. “The initial realization is, ‘I am not alone.’