If you watch a child stare in amazement at the flickering candle on their first birthday cake, it’s clear that something is going on behind those big, innocent eyes.
It wasn’t always like this. Rewinding the clock, from the curious baby to the newborn to the fertilized egg, that consciousness becomes increasingly difficult to recognize.
Beyond the philosophical challenge of defining consciousness, scientists have also had difficulty determining precisely when a developing network of neurons has enough complexity to not only sense, but also perceive its environment.
Some suggest that consciousness arises many months after birth, shortly before the first birthday. Others maintain that our first moments of consciousness could occur shortly after birth.
“Almost everyone who has held a newborn has wondered what it’s like to be a baby, if anything,” says Tim Bayne, a philosopher at Monash University in Australia.
“But, of course, we cannot remember our childhood, and consciousness researchers have not agreed on whether consciousness arises ‘early’ (at birth or soon after) or ‘late’: at one year of age, or even much later.”
To summarize the current state of progress on the topic, Bayne and a small team of neuroscientists and philosophers from Australia, Germany, the United States and Ireland conducted a review of the literature to date.
Based on their findings, there is enough evidence to argue for an early state of consciousness, one that could operate long before birth.
Consciousness is the black hole of neurology; a singularity hidden by an event horizon of subjective experience that no one else can access. We can only assume that other brains – like ours – can turn acoustic vibrations into songs of joy and sadness, electromagnetic waves into blue skies and warm sunsets, or the smell of skin into maternal comfort.
Without any meaningful way to distinguish conscious action from unconscious reaction, a physical theory of human consciousness continues to challenge researchers. We barely understand how it works inside a mature brain, let alone one still under construction.
The implications are not trivial either, extending beyond neurology to computer science, ethics, and even law.
Without a means to share possible perceptions of the world, babies were once assumed to lack true consciousness.
For much of history, well into the 20th century, medical procedures could be performed on babies with minimal, if any, painkillers under the belief that they lacked the awareness necessary for painful stimuli to register as distressing. .
The authors of this latest review present four lines of evidence supporting the emergence of consciousness near birth, citing advanced connectivity throughout the brain, indicators of attention, research involving the integration of information from various senses, and physical markers involved in consciousness. surprise and reorientation of attention. .
“Our findings suggest that newborns can integrate developing sensory and cognitive responses into coherent conscious experiences to understand the actions of others and plan their own responses,” says Trinity College London psychologist Lorina Naci.
That doesn’t necessarily mean that consciousness is suddenly activated at birth, but rather that we might expect a gradual awakening of experience that develops as synapses fuse, senses fuse, and cognition builds patterns that can be challenged as they emerge. new stimuli.
Questions about whether consciousness is partial or complete, whether fetuses dream, or even how we can relate to a newborn’s own consciousness, are still far from being answered.
As brain scanning techniques improve and we can better map the complex weaves of neurological networks as they grow, we might come to understand consciousness as a continuum.
This research was published in Trends in Cognitive Sciences.