Every moment of our life joins together a multitude of events: voices become speech, faces are recognized, memories come alive, and we feel our own presence in the world. From this dynamic interaction a coherent experience emerges — as if individual notes were folding into a melody. A new study by Andrea Luppi and his colleagues offers a glimpse into the neural mechanisms that bind together the scattered signals of the brain and create the continuity of consciousness.
The work, published on 29 September 2026 in the journal Nature Neuroscience, presented an ambitious comparison: the researchers analyzed the neural activity of six animal species — humans, macaques, marmosets, mice, zebrafish larvae and the microscopic roundworm Caenorhabditis elegans. They tracked what happens in the brain during wakefulness and under anesthesia, processing the characteristics of more than six thousand neural activity signals. The scale of the analysis is unprecedented: from the higher primates to creatures with just a few hundred neurons.
Behind this vast diversity of nervous systems lay an unexpected order. Anesthesia slowed the internal rhythms of neural activity and weakened the coherence between different parts of the brain. In organisms so unlike one another, a strikingly similar state arose: activity became more isolated, as if each neuron began to live by its own laws, losing connection with the whole.
This can be pictured through a simple dialogue. When interlocutors listen to each other, words interweave with the memory of previous phrases — the conversation acquires depth and meaning. In neural activity there is an analogous process: the signal at each moment carries within it an echo of what came before. This property, called memory of the system in physics, sustains the continuity of consciousness. Under anesthesia this trace is erased more quickly — the neuron "forgets" its past. At the same time, different parts of the brain lose coherence: if the waking brain works like a well-coordinated orchestra, then under anesthesia each instrument begins to play its own part without connection to the others.
The most striking evidence came from an experiment on macaques. When the researchers electrically stimulated the centromedian nucleus of the thalamus — a deep brain structure associated with awakening — the animals again began to respond to their surroundings, despite the continuing administration of the anesthetic. Neural activity changed accordingly, approaching the patterns of wakefulness. This discovery underscores the critical role of the thalamus: this small structure, the size of a bean, acts as the main switchboard, connecting the scattered parts of the brain into a single whole.
But here it is important to be honest in interpretation. The study revealed similar changes under anesthesia and in the loss of behavioral reactivity. However, the question of whether all the organisms studied experience subjective experience, and of how exactly the discovered processes are related to consciousness, remains open. The worm may simply be sensitive to chemicals, without having any inner world. Understanding this boundary is one of the main riddles of modern neuroscience.
Nevertheless, the study reveals a profound truth: consciousness rests on two pillars — on the ability of the nervous system to bind events in time and to coordinate the activity of its parts. In this light, the metaphor of melody ceases to be merely a pretty image. Each note sounds separately, but their interrelations create music. It is precisely these interrelations, this web of relationships between neurons, that is what allows us to be ourselves — whole, coherent, present in the world.
