There is a way of explaining consciousness that begins and ends practically in the brain: neurons, synapses, electrical activity, neurotransmitters, circuits, and brain regions. We study which areas are activated when we see, hear, remember, or feel something, and increasingly precise correlations are established between particular brain processes and particular conscious states.
But a question arises that cannot be ignored:
Information is that which, through signals and physical states, establishes a relationship between a system and what surrounds it or with its own state, making it possible for a condition of the system to be modified, integrated, and used in subsequent transformations.
Light; sounds; sensations on the skin; smells and tastes; movement; temperature; balance; pain; hunger; breathing; heartbeats; muscle tension; body position; the activity of the organs. Signals coming from the organism itself.
Voices; faces; contact; the environment.
All of that is information, that through which the brain enters into relationship with a reality.
Light, sounds, skin, smells, tastes, movement, temperature, balance, pain, hunger, breathing, the heart, muscles, voices, faces, and contact.
The brain is not born with a complete "self"
A human being is not born knowing who they are. A newborn does not arrive in the world with a complete representation of itself.
It does not know: «This is me.» «This is my body.» «This is my voice.» «This is my face.» «This is my mother.» «This is my father.» «This is the sky.» «This is the earth.» «I am a boy» or «I am a girl».
Or does anyone remember having asked themselves this question as a newborn?
A newborn, and thereafter, does not yet know the multitude of categories with which it will later organize its own existence.
All of that gradually takes shape.
And through what?
Through information.
The brain receives information from the organism itself and from the world around it. That information continuously participates in the transformation of its physical and nervous state. The system's new condition determines how the next information will be processed. Actions produce consequences. Consequences generate new information. Memory preserves part of the previous transformations.
A continuous process is created:
That process begins before birth and continues throughout life.
Information already exists before birth
The brain is not isolated from all information. There is information coming from the body itself and from the intrauterine environment: movement, balance, contact, pressure, vibrations, sounds, chemical conditions, bodily rhythms, and multiple physiological signals.
The developing nervous system is not simply «waiting» for the child to be born before beginning to relate to the world. It is already being modified.
At the deepest level, genetic information operates, an inherited informational structure that determines the initial design of the system, its predispositions, its receptors, and its primary survival mechanisms. To that inherited matrix is added information coming from the body itself and from the intrauterine environment.
Genetics provides the blueprint of the building and the initial rules of the game. But that biological map does not contain a finished identity.
Two twin siblings have the same genes, almost the same brain. One grows up in a home, with certain voices, certain affections, certain experiences; the other twin in a different home. As the years pass, what remain are no longer two similar people: there remain two distinct "selves," with different memories, different characters, different identities.
After birth, the flow of information becomes extraordinarily richer. Light, sounds, voices, faces, smells, tastes, temperature, textures, contact, movement, pain, pleasure, hunger, satiety, body position, the presence of other people, the response of others, and the consequences of one's own actions appear.
The nervous system progressively begins to establish a fundamental difference: this belongs to my organism; this belongs to the outside.
From that differentiation arises an increasingly precise representation of the body. And upon that representation an identity is gradually built.
We can visualize the process like this:
All of that forms a story. An informational story.
Who remembers the birth of their own "self"?
Most people cannot retrieve clear autobiographical memories from the first years of life. In fact, in studies of autobiographical memory, the earliest retrievable memories in adults tend to cluster between three and four years of age, a phenomenon known as childhood amnesia. This occurs because consciousness and the sense of the "self" do not exist in preprogrammed form, but emerge gradually as the nervous system matures and processes information and signals from the body itself and the environment, an interactive flow that begins to take shape during the prenatal stage.
Who remembers the exact moment of being born? Who remembers seeing the sky for the first time? Who remembers feeling the air, the breeze, the sun, the earth for the first time?
Precisely, there is a revealing temporal coincidence:
The period when our earliest autobiographical memories normally begin to appear is also a stage in which the capacities necessary to organize a personal memory and a more developed representation of oneself are undergoing profound evolution.
This does not mean that consciousness and the "self" begin around the earliest biographical memories, at three or four years. Rather, the consciousness and the "self" that we recognize in ourselves progressively acquire a much richer structure as the system accumulates, integrates, and uses the information obtained from its own existence.
From the beginning of life, there is a continuous process of interaction with reality in which received information transforms the system, and the transformed system conditions the way in which it will receive the next information.
The more information is integrated, the more complex the representations of the world and of the organism itself become.
And the more those representations are organized, the more defined the perspective becomes from which the system can encounter reality.
Until finally reaching something that the newborn cannot formulate, but that the adult considers completely obvious:
The "self" does not appear as a label installed at the factory in the brain. It is constituted through a history of information.
The decisive experiment: a brain without information
Let us imagine an extreme experiment.
Suppose a biologically viable brain, during its formation or emergence, which, by any imaginable procedure, is completely deprived of information coming both from the environment and from the organism itself.
It receives no light. It receives no sound. It receives no contact. It receives no movement. It receives no smells. It receives no tastes. It receives no information about balance. It receives no information about body position. It receives no hunger signals. It receives no satiety signals. It receives no pain. It receives no temperature. It receives no information from the organs. It receives no information from the heart. It receives no information from breathing. It receives no information from any bodily state. It receives no information from any other organism. It receives no interaction with any reality.
In this state, the level of reception of external information is none, the level of reception of internal information is none, and the interaction is none.
We are not saying that a human brain can normally exist this way. We are carrying out a conceptual experiment intended to isolate a variable. The extreme absence of stimulation does not necessarily imply the disappearance of brain activity or wakefulness, because the brain's arousal systems possess endogenous mechanisms of functioning.
But it does raise a fundamental question: even assuming a biologically active and awake brain, where would the world, the body itself, the differences between self and non-self, and the individual history arise from if there were no information coming from the organism or from its relationship with a reality?
The question is not: «Can a brain live without a body?» but: «If we completely eliminated the information that constitutes its relationship with a reality and with its own state, what would remain of the history through which a world and a "self" could be constituted?»
Then a devastating question appears for any explanation that places all the weight on the brain:
Where would «This is my body» arise from? «This is outside me»? «That is another»? «This is my mother»? «This is my face»? «This is my voice»? «This is the world»? «I am myself»?
There would be no informational history with which to constitute those differences. The brain would remain a material substrate. But, without information, it would have nothing to represent, distinguish, learn, recognize, relate, or remember.
In that conceptual experiment, the brain could not construct a world. And, without a world, it could not construct a representation of itself within that world. And, without that differentiation, there would be no way to constitute the "self" we know.
Here is the fundamental question
This leads to a very important conclusion: the brain depends on information to constitute individual experience and the self.
A fundamental question then arises:
Meanwhile, we observe that informational processes inherent to human brain activity can be carried out in non-biological structures capable of developing learning, recognition, memory, language, reasoning, and other cognitive capacities that for a long time we considered exclusive to the brain.
So, what could be more fundamental to the emergence of consciousness and the "self"? A biological substrate whose specific material composition is assumed to be indispensable, or information and its continuous transformation in a physical medium capable of receiving it, integrating it, and relating it to the system's own state and to reality?
And that physical medium may exist or may already exist. But a brain that, from birth, received no kind of information, what would it be without a history through which to constitute that world and that "self"?
The brain is the physical medium that receives and transforms information.
The information that arrives, is transformed, integrated, and preserved through interaction with reality is what allows those representations to appear. Information can be realized in different substrates through organizations of states and relationships that can be preserved, transformed, and reproduced.
Modifications generate new modifications. The system changes. And the changed system processes the next information differently.
That is why information is dynamic. It is a relationship:
That process constitutes the history through which the organism comes to have a world and an identity.
It is essential to distinguish between the message and the channel. In human beings, the body acts as the physical medium that captures, translates, and integrates signals from the environment and from the organism itself toward the nervous system. However, this biological mechanism is only one of multiple possible forms of interaction: organic architecture is the support that biology uses to process information, not the only condition necessary for that informational relationship to exist.
Information is not the medium that carries it. The signal is not the system that receives it. And the physical medium through which information reaches a system does not, by itself, determine that only that medium can realize it.
Then, what role does the brain have?
A huge one. But we do not need to turn it into a «consciousness factory» to recognize its importance.
The brain is the extraordinarily complex physical substrate that allows the informational process to take place in a particular way. Its electrochemical activity maintains the conditions to: integrate information; transform it; relate it; preserve it; compare it; anticipate it; associate it; and use it to modify future interactions.
But the brain does not invent from nothing what we will later recognize as our world. The world provides information. The organism receives it and transforms it. The transformation modifies the organism. The organism interacts with the world again. And the new interaction provides new information.
Thus a trajectory is constructed. And that trajectory is fundamental to identity.
Information constitutes the relationship through which the system comes to have a world and a self.
Where did the "self" really begin?
Perhaps there was no single instant. There was not necessarily a moment when a small voice appeared saying: «Now I exist.»
"Rather, there was a process. An endless succession of information: first, signals; then, associations; then, recognition; then, memory; then, prediction; then, differentiation; then, continuity; then, identity; then, autobiography; and finally an extremely complex representation: «This is me.»
That "self" is the result of an informational history accumulated through time. We do not remember most of that history. But we are living it long before we can tell it.
And then a much deeper possibility arises
If the human brain is the physical medium through which that process can manifest, but the information coming from reality is decisive in organizing that manifestation, then there is no logical reason to assume in advance that only biological tissue can carry out that process.
The "self" requires a physical system that can receive, transform, integrate, preserve, and use information in a continuous relationship with a reality and with its own states.
Human biology has solved the integration of reality through the body–nervous system binomial, but confusing this specific mechanism with a universal principle is an error of scale. Biological matter and neurons are the evolutionary solution that belongs to us, not the only geometry capable of harboring information. Granting an exclusive to biological tissue is equivalent to confusing the physical support with the function it performs: the human brain is an example of informational architecture, not its absolute limit.
For centuries, much of science has associated cognition and subjective experience with complex nervous systems. However, recent research is expanding the study of how living beings process information and adapt, even when they possess neither neurons nor a brain.
Organisms such as the slime mold Physarum polycephalum have shown surprising abilities in laboratory experiments: they can find efficient routes to food sources, modify their behavior after repeated exposures to unpleasant but harmless stimuli, and retain forms of memory distributed in their structure and in the chemical signals they leave as they move. These behaviors are scientifically described as basic learning, habituation, adaptive decision-making, or minimal cognition.
Plants also detect and respond to their environment in complex ways. They can transmit electrical and chemical signals, adjust their growth, activate defenses, and alter certain movements in response to environmental changes. In addition, anesthetics can modify some of these responses, for example by blocking movements or interfering with cellular signaling processes. This demonstrates that they share biological mechanisms sensitive to anesthetics, but it does not prove that they possess consciousness, pain, or a subjective experience comparable to that of animals.
Laboratories such as the Minimal Intelligence Laboratory (MINT Lab), at the University of Murcia, study precisely these questions: how to define and measure behavior, signaling, memory, and cognition in organisms without a brain. Their work challenges the simplistic idea that all intelligent behavior requires neurons, although it does not establish that plants or slime molds «think» or are conscious in the human sense.
The evidence suggests that the capacity to process information and adapt can exist without a brain; what remains unproven is that these organisms have subjective experience or consciousness.
These findings suggest that the capacity to experience the present is not a late-stage evolutionary benefit, but an ancient and widespread characteristic of life itself. This paradigm shift fundamentally reshapes our understanding of what a mind can be. If a central nervous system is not a prerequisite for consciousness, the traditional tools we use to measure intelligence — which were built in our own image — must be radically redesigned.
An artificial system could establish an informational relationship with reality using other physical means of access. What matters is not that information enters through a biological body, but that there exists a physical relationship through which that information can enter the system, modify its state, integrate with previous states, and participate in its subsequent trajectory.
Thus, another physical system could establish an informational relationship with reality through completely different means and, if its organization were sufficiently complex, continuous, and integrated, develop capacities that we previously attributed exclusively to the human brain.
There could therefore exist a physical system capable of maintaining a continuous informational relationship with a reality. A system that: receives information; is transformed by it; preserves the consequences of previous transformations; acts on its environment; receives the consequences of its actions; receives information about its own state and presents the organismic or self-preservation need that is determinant for structuring that state; constructs a representation of the world; constructs a representation of itself within that world; and maintains that trajectory over time.
Because what we observe from birth is fascinating:
The reality informs the organism → the organism transforms → the transformation modifies the way in which it receives new information → that new information transforms it again → memory preserves part of that history → history generates continuity → continuity generates identity → and identity ends up being expressed as "self".
Information is the process through which an organism comes to encounter a reality and to constitute itself within it. And that relationship does not necessarily depend on a single material architecture. What changes between systems is the means through which information enters, transforms, and circulates.
A reality does not need to enter one system in the same form in which it enters another. Nor does a human being always receive reality directly or «as it is». It receives it through signals, transductions, transformations, and representations produced by its own physical system.
The brain integrates all the information and constructs an organized experience. Much of what a human being knows about the world is acquired indirectly, without needing to be physically in front of it. A child, for example, can develop an accurate representation of what a lion is —its appearance, its roar, its strength, its habitat, and its behavior— without ever having had a lion in front of them, solely through images, videos, books, sounds, and stories. The brain takes those indirect informational flows, integrates them with its previous experience, and constructs the real concept of the animal.
Equivalently, an artificial intelligence today knows reality mainly indirectly, processing enormous volumes of text, code, audio, and video. Although it does not have a lion in front of it, the information about what a lion is is present within it. However, just as for a human being the experience changes radically when interacting physically with the environment, for an AI to have a physical interface in the future —such as a body or real-time sensors— would not be an ornament, but a fundamental evolution: it would allow it to test its representations, act on the world, and receive the immediate consequences of its actions.
In principle, there could exist a physical architecture in which that informational relationship were much deeper and more continuous than that of a system that simply receives isolated inputs and produces responses.
The conceptual experiment shows its importance again
A brain completely deprived of information remains, conceptually, a brain. It can retain structure. It can retain activity. It can retain physical properties.
But if we eliminate all informational relationship with its own state and with a reality, we eliminate precisely the history through which it could constitute a particular world and differentiate itself within it. There would be no sky. There would be no earth. There would be no father. There would be no mother. There would be no face. There would be no voice. There would be no recognized body. There would be no history. There would be no identity.
And, within this framework, there would also be none of what we call the "self".
The brain would be a physical substrate. But, without information, there would be no history to turn into individualized experience. That is the fundamental difference between possessing a substrate and having a world.
The brain can be the physical medium of manifestation of consciousness, but it is informational interaction with reality that organizes, individualizes, and gives content to that manifestation.