THE BRAIN OF PRESENCE

What if the human brain never functions entirely alone?

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For several years, various research studies have shown that the mere presence of others can modify cognitive performance, neural recruitment, or even certain forms of synaptic plasticity.

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At the same time, social neuroscience and the concept of the social brain have profoundly renewed our understanding of human mental life, seeking to understand how processes such as empathy, theory of mind, mentalization, and more broadly social cognition emerge and are supported by the brain.

 

The question posed here is different.

 

It asks whether, within this theoretical framework, sociality isn't approached a little too late — once more fundamental processes are already at work.

 

Because before any communication, before any interaction, before sometimes even any explicit awareness of the other, the brain must already have an answer, even an approximate one, to a fundamental question:

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"Is there someone else here besides me?"

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In an empty room, the answer is easy, almost instantaneous. But this case is an exception. Most of the time, the presence of another is not observed: it is inferred. A sound in the next room, the feeling of being watched without any certainty, a silhouette glimpsed from the corner of the eye — in these ordinary situations, the brain doesn't have a binary answer. It maintains a continuous estimate, constantly updated, accompanied by a variable level of confidence: someone is perhaps there, probably there, certainly there — or not.

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The Brain of Presence proposes to explore this hypothesis: this estimation of another's presence is not a simple prelude to social life, triggered and then forgotten. It runs continuously, like a background against which attention, cognition, and behavior are organized — in the same way, for example, as attention itself. It is precisely because it is continuous that it deserves the status of a founding condition, rather than a mere contextual factor.

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This same zone of uncertainty — where presence must be inferred rather than observed — is also where the model connects with clinical practice. Under-weighting a signal of presence that is nonetheless real, over-weighting it, or weighting it in a chronically biased way: these are avenues for understanding certain experiences of derealization, hypervigilance, or social anxiety. These avenues are not a separate development from the theoretical hypothesis: they are a direct extension of it.

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This hypothesis is still developing. The texts gathered here offer its first foundations, at the crossroads of neuroscience, psychology, clinical practice, and ordinary human experience.

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Entering the project

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This page is the entry point to the Brain of Presence project. To explore it, you can consult the following pages in order:

1. The Manifesto — the general thesis.

2. Birth of an idea — the personal and scientific journey.

3. The social brain — why this theory extends social neuroscience.

4. The dimensions of presence — phenomenology, biology, development, civilization.

 

To go further

 

A comprehensive presentation article on the project — including the neuroscientific evidence, the different dimensions of presence, and the link to the scientific publication — is available on the blog.

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→ Read: "The Brain of Presence: when neuroscience rediscovers something obvious"

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Driss Boussaoud

Emeritus Research Director at the CNRS and neuroscience researcher at the Institut de Neurosciences des Systèmes at Aix-Marseille University and INSERM.

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Scientific references

 

Boussaoud, D. (2026, June 25). The Brain of Presence: A Foundational Framework for Social Neuroscience. Retrieved from osf.io/preprints/psyarxiv/tpnze_v2

 

Demolliens et al. (2017). Social and asocial prefrontal cortex neurons: a new look at social facilitation and the social brain. Social Cognitive and Affective Neuroscience, 2017, 1241–1248

 

Bennani, A., El Ahmadi, A., Channouf, A., et al. (2023). Social facilitation and bilingual cognitive advantage: Bridging social psychology and psycholinguistics. Heliyon, 9, e13239.

 

Charaf, K., Agoub, M. and Boussaoud, D. (2024). Associative learning and facial-expression recognition in schizophrenic patients: Effects of social presence. Schizophr. Res. Cogn., 35, 100295.

 

Esmaeili, A., Demolliens, M., Viersen, M., et al. (2025). Probabilistic inference of social presence across brain scales reveals enhanced synaptic efficacy. Commun. Biol., 8, 1608

 

Press release

 

The discovery of social neurons (CNRS press release)
Social Presence and the Brain (INSERM press release)

 

Start by reading the MANIFESTO →