How do we learn to make sense of the world of phenomena that constantly stimulate our senses? Is it something that happens in response to the sensory experiences that bombard us from before birth? Or is it rather the result of innate structures, which give meaning to experiences through preordained patterns? The answer of a great philosopher like Immanuel Kant is that knowledge always arises from experience, which however reaches the intellect through two pure and a priori forms, space and time, and is then elaborated using a series of a priori structures, the categories, which organize and unify sensory data. A few centuries later, today even science seems to agree with him, in some way: research from the University of California in Santa Cruz has demonstrated that the very first electrical activities of the brain are not random, but ordered according to patterns that suggest the existence of an innate configuration that helps us interpret sensory stimuli, and thus interact with the world.
The research
The study was carried out using organoids, three-dimensional structures obtained from stem cells, which reproduce the functioning of an organ in a small way. In this case, obviously, they were brain organoids. A perfect experimental platform to study the development of the brain, and the evolution of its functioning during the early stages of fetal maturation.
In the research, the organoids were left to develop for several months, during which the researchers studied their electrical activity using specialized microchips. In this way they observed that the activity of neurons in the very early stages of brain development spontaneously follows activation patterns, or “neuronal sequences”, which in the mature brain are associated with specific sensory activities. In the adult brain, similar neuronal firing sequences are thought to encode an important part of the information processed by the brain. And since in the experiment they were observed in organoids without sensory input, they must have arisen spontaneously, in the absence of any experiential stimulus.
What does it mean?
The architecture of the brain would therefore appear to produce innately (a priori, as Kant would say) the neuronal activation sequences that will serve to interpret the data of experience and navigate our world. In other words, the structures necessary to order sense data are already present in our intellect, before it experiences the sensory data it has the task of interpreting. Exactly as imagined by the great philosopher from Königsberg.
In more contemporary terms, the authors of the study hypothesize that our brain possesses innate activation sequences, fixed in our genome and shaped by evolution, which during development are recruited and optimized to process sensory stimuli. A fascinating conclusion, which confirms the usefulness of cerebral organoids for studying the functioning of the most complex organ in our organism. And which could have important implications in the field of health in the future.
“We are demonstrating that there is a basis for capturing complex dynamics that could be signals of pathological onset that we could study in human tissues,” underlines Tal Sharf, professor of biomolecular engineering at the Baskin School of Engineering who led the research. “This would allow us to develop therapies, working with clinicians at the preclinical level to develop cheaper, more efficient and productive compounds, drugs and gene editing tools.”
