‘Criticoma’ concept proposed to address critical periods of brain development up to young adulthood

The concept of the ‘criticome’ seeks to define how the human brain constructs and shapes itself through interaction with the world at specific moments. This is not a new idea; Cajal already made this clear with his famous statement that ‘man, if he so chooses, can be the sculptor of his own brain’. Indeed, during periods of maximum plasticity (such as childhood, though not exclusively, as cortical maturation is not complete until after the age of 20), the brain absorbs all the information it is given like a sponge and processes it, physically encoding experiences within its neural circuits. The term ‘criticome’ refers to the set of critical periods during which neural plasticity is at its peak and, consequently, the brain is highly malleable. The authors identify various biological phenomena, ranging from foetal stages to adulthood (up to the age of 25), to define the criticome, which results in the formation of individual personality. Certainly, the various critical periods that make up the criticoma are defined by specific molecular and cellular mechanisms that create windows where synaptic plasticity is optimal.

This integrative concept serves as a reminder that it is important to fully grasp that everything we see, hear, smell or feel, together with the emotions it provokes in us, leaves an imprint on our neurons and how they interconnect. All this information is structurally integrated into the brain’s architecture with characteristics that are not consciously accessible, but which profoundly influence perception, cognition and behaviour throughout life. Movements, gestures and the way we physically interact with our environment are recorded as patterns in our nervous system. The way we relate socially, family dynamics and social hierarchies also define how our social neural networks are wired. The same applies to culture. The language we learn, the symbols and rituals we observe are biologically assimilated during critical windows of development. Finally, the environment or setting—from the architecture of our home to the nature around us and the socio-economic conditions we enjoy—acts as the real-world backdrop that either limits or enhances our entire development. In short, the human being is a biological fusion of what they perceive, how they move, who they interact with, the culture in which they grow up, and the physical place where they live.

And in this context, once again the wise Cajal was right when he said, “the man who poses a problem is not entirely the same as the one who solves it”. Hence the importance of young people’s education, the environment in which they develop, and so on, because the experience gained determines the kind of person one becomes.

Although the concept is not entirely new, the authors propose that understanding the criticome opens up new avenues for both social and therapeutic design in mental health through new approaches such as reopening critical periods, using pharmacological or behavioural interventions to make the brain malleable once more and thus be able to modify traumas or pathological patterns rooted in childhood. This proposal—to heal the mind by directly intervening on the biological imprints that early experiences left on the brain—is very interesting and brings together a series of previous observations made by various neuroscientists.

But the proposal for a pedagogy based on critical periods can also serve to design educational interventions adapted to the specific times when different brain systems are most receptive to learning. For example, based on these critical periods, delaying the teaching of second languages until adolescence would be counterproductive, because exposure to a language during the early critical periods would allow it to become structurally integrated into the brain’s architecture in a profound way—a process that cannot be replicated in later stages of life. It is common knowledge that children find it easier to learn a second language compared to the difficulty of doing so in adulthood, not to mention the accent.

Similarly, early exposure to complex motor patterns (such as sport, music or dance) during periods of high plasticity creates the neural circuits that form the basis for future virtuosity. In fact, it is well known that elite athletes and artists begin training in childhood not only to accumulate hours of practice, but because the brain architecture necessary for complex motor control can only be optimally established during these critical windows of development.

The article is a theoretical exploration that seeks to understand the complex interplay between genes, environment and the passage of time in the development of mental illness and other social factors such as ideological indoctrination or chronic geopolitical trauma. To this end, it proposes a new concept, the ‘criticome’, which aims to encompass all the experience acquired by the nervous system during critical periods of development and synaptic plasticity up to the age of 25, with the intention of generating knowledge and therapeutic, educational and cultural benefits always related to mental health.