Where Does a Mind End During a Conversation?

Perhaps a conversation does not exist entirely inside either brain — and perhaps a “we” begins when one person’s movement starts changing what becomes possible for the other

Imagine two people who have never met.

They sit facing each other.

One begins to speak.

The other listens.

One sentence triggers another.

The tone changes.

The rhythm changes.

Sometimes one person completes the other’s thought.

Sometimes something difficult to explain happens:

the conversation begins to flow.

In other encounters, it does not.

There are words.

There are responses.

But something never quite forms between the two people.

In 2026, Marcos Domínguez-Arriola and colleagues published a study in NeuroImage examining part of this phenomenon during naturalistic conversations.

The question was fascinating:

What happens to voice, subjective experience, and brain activity when two people feel that an interaction went well?

To investigate this, the researchers did not record only one brain.

They recorded two brains simultaneously using EEG.

This is known as hyperscanning.

And here, an apparently technical question becomes much larger:

What can we see when we stop studying only “me” and begin measuring “me while I am with you”?

Two brains during a real conversation

The participants did not know each other beforehand.

Organized in pairs, they held short, free conversations on different topics while researchers simultaneously recorded the speech and brain activity of both participants.

They also evaluated aspects of the quality of the interaction.

The study examined different forms of coordination.

Voice with voice.

Did characteristics of the two people’s speech begin to converge?

Brain with speech.

Did neural activity track speech differently during interactions judged to be better?

Brain with brain.

Were particular temporal relationships between the two EEG signals associated with the perceived quality of the conversation?

This distinction matters because “being together” did not appear as a single phenomenon.

Pairs who developed more positive mutual impressions showed greater prosodic convergence across the interaction.

Characteristics of their voices began to become more similar.

At the brain-to-brain level, conversations rated as higher quality showed stronger interbrain relationships in the alpha and theta bands, particularly near-zero-lag alpha coupling.

But the different measures did not tell exactly the same story.

And perhaps that is more interesting than if everything had simply “synchronized.”

Synchrony does not mean one mind

We need to avoid a seductive interpretation:

“Two brains synchronized, therefore they became one mind.”

The study does not demonstrate that.

Neural synchrony is not friendship.

It is not automatically cooperation.

It is not belonging.

It is not Jiwasa.

The finding is more precise:

Certain temporal relationships between the neural signals of two people tracked aspects of the quality they attributed to a natural conversation.

Up to this point:

Domínguez-Arriola and colleagues.

But this allows us to ask:

Are there human events whose minimal unit of analysis cannot be the isolated individual alone?

To reach that question, it may help to begin with something simpler.

When an object begins to participate in the body

Think of an experienced artist using a brush.

A tennis player using a racket.

An athlete using specialized equipment.

A musician using an instrument.

After extensive practice, the relationship with that object can become so precise that the person no longer needs to consciously calculate every centimeter separating body and tool.

The body learns to act through it.

The tool does not biologically become part of the organism.

But it can function as an extension of the action repertoire.

A tennis player perceives possibilities with a racket that an inexperienced person may not perceive.

A painter senses differences through the brush.

A musician organizes movement through the instrument.

In BrainLatam terms, we can ask:

Can a tool expand the APUS of a Body-Territory?

It allows the person to reach, perceive, or produce movements that may not exist in the same way without that relationship.

But something changes radically when what is in front of us also has a body.

When the other is not a tool

Think about equestrian sport.

There is the rider.

And there is the horse.

The horse is not a passive extension.

It has a nervous system.

Perception.

Physiological state.

History.

Fear.

Learning.

Its own possibilities for movement.

The rider does as well.

When both enter into movement, we no longer have:

Body → tool → world.

We have:

Body ↔ Body.

The rider senses small changes in the horse’s rhythm, tension, direction, and movement.

They adjust pelvis, trunk, legs, hands, and weight distribution.

The horse perceives that adjustment.

Responds.

That response returns to the rider.

Who must adjust again.

We have a cycle:

horse perceives → responds → rider perceives → responds → horse perceives...

Neither organism possesses the final movement alone.

The movement emerges from the relationship.

High performance does not mean disappearing into the other

This example helps reveal an essential distinction.

When we use a tool, the goal may be to incorporate it into our control.

But when we are interacting with another organism, high performance should not simply mean controlling it.

In the horse-rider system, if the rider becomes completely rigid and imposes every movement, the relationship deteriorates.

If the rider becomes completely passive, the same level of coordination is also lost.

The system depends on reciprocal perception and adjustment.

This allows us to turn an abstract word — respect — into a more experimental question:

Could respecting another organism mean perceiving its signals without cancelling them, while adjusting our own movement without destroying the partner’s ability to respond?

If we think in these terms, high relational performance would not be:

A dominates B.

Nor:

A disappears into B.

It would be:

A and B construct a shared movement while each remains capable of perceiving and modifying the other.

And here we begin to approach Jiwasa.

Jiwasa: me, you, and what neither of us can produce alone

Jiwasa is not an EEG frequency.

It is not alpha synchrony.

It is not a brain region.

Domínguez-Arriola and colleagues did not study Jiwasa.

In the BrainLatam framework, we use Jiwasa to ask about shared agency.

A conversation offers a simple example.

I alone cannot produce our conversation.

You alone cannot either.

Each of us has our own history, body, and possibilities.

But once we interact, my next movements begin to depend on yours.

My sentence changes your next response.

Your facial expression changes what I am about to say.

Your silence may reorganize my next movement.

So we can ask:

What happens when the APUS of one Body-Territory begins to be modified by the possibilities offered by another Body-Territory?

Perhaps a tool expands my APUS.

But another Body-Territory may help construct:

our field of possible movements.

That difference is fundamental.

Jiwasa does not require two bodies to become the same

Perhaps a good “we” is not one in which differences disappear.

In high-level equestrian performance, horse and rider do not need to become the same organism.

In music, two performers do not need to play the same note.

In conversation, two people do not need to hold the same opinion.

Perhaps Jiwasa appears precisely when different movements can build something in common without one having to completely eliminate the other.

That is why:

Synchronizing does not mean belonging.

And we can add:

Coordinating does not mean submitting.

Two people may march together because they are ordered to.

A crowd may repeat the same word.

Millions may receive the same stimulus from an algorithm.

There is synchrony.

But there may be no reciprocity.

That is where we need more than EEG.

QSH: when we perceive that we are part of something

At BrainLatam, we use Human Quorum Sensing — QSH as a hypothesis for asking how a person’s movements may change when they perceive themselves as part of a collective.

There is no electrode that can say:

“Belonging started here.”

We would need to combine different levels:

EEG or fNIRS hyperscanning.

Movement.

Voice.

Respiration.

Heart rate.

Behavior.

Subjective report.

Context.

And also something fundamental:

power.

Because two people may show coordination while still having very different capacities to modify the relationship.

The Latin American question

Imagine two people talking.

Both speak Spanish.

Now imagine:

one speaks Spanish and the other Aymara.

Or Guarani.

Or another Indigenous language whose relationship with territory, agency, and collective life organizes experience differently.

Imagine a conversation between two people with similar social positions.

Then one between a person with substantial institutional power and another whose life depends on that institution.

EEG may register coordination.

But we still need to ask:

Who can interrupt?

Who can disagree?

Who has to adapt their language?

Who is allowed to remain silent?

Who must abandon their own semantics in order to continue belonging?

This changes the problem profoundly.

Because a high-performance Jiwasa may not be one in which everyone becomes alike.

It may be one in which the relationship produces coordination without destroying the diversity of the Body-Territories that compose it.

Could we also study a multispecies Jiwasa?

The horse-rider system opens another question.

Does Jiwasa necessarily have to exist only between humans?

We do not know.

But we can investigate.

Imagine comparing:

novice rider + horse;

experienced rider + familiar horse;

experienced rider + unfamiliar horse.

We could record the movements of both.

Saddle pressure.

Rein tension.

Heart rate.

Heart-rate variability.

Respiration.

Muscle activity.

Timing of corrections.

And, when technically feasible, EEG or fNIRS from the rider.

Then ask:

When do two organisms begin to construct a movement in which small changes in one are perceived and incorporated by the other?

Not in order to claim that horse and rider “are Jiwasa.”

But to ask something more interesting:

Does shared agency require language, or can it begin in the coupling between bodies capable of sensing and responding to one another?

Where the article ends and BrainLatam begins

Domínguez-Arriola and colleagues showed that, during natural conversations, different forms of coordination tracked different aspects of interaction. Interbrain relationships in alpha and theta tracked perceived conversation quality, while prosodic convergence was related to the development of more positive interpersonal impressions.

Up to this point:

Domínguez-Arriola and colleagues.

From this point onward:

BrainLatam.

The study did not measure Jiwasa.

It did not measure QSH.

But it allows us to ask a fundamental question:

If we can measure aspects of coordination that emerge between two people, can we investigate when that coordination begins to produce possibilities that neither participant could produce alone?

And then:

When does coordination become reciprocity?

When does reciprocity become belonging?

When does belonging expand the possible movements of each participant?

And when does the collective, instead, begin to narrow them?

Perhaps the most important question is not where a mind ends.

Perhaps it is what happens when two minds remain different and still manage to construct a shared movement.

A tool can expand my movements.

Another Body-Territory can modify my movements while I modify theirs.

And perhaps Jiwasa begins precisely in that difference:

not when we stop being “me” and “you,” but when a movement appears that can exist only because there is a “we.”

Neuro Challenge Latam

Think of a relationship in which you truly built something with another person.

Did what emerged belong to you, belong to the other person — or could it exist only because both of you participated in constructing the next movement?

Scientific Reference

Domínguez-Arriola, M. E., Lam, P. C. H., Pérez, A., & Pell, M. D. (2026). Interpersonal neural coordination tracks interaction quality during naturalistic conversation. NeuroImage, 338, 122090. https://doi.org/10.1016/j.neuroimage.2026.122090