Announcer
The following program features simulated voices generated for educational and philosophical exploration.
Rachel Foster
Good evening. I'm Rachel Foster.
Greg Collins
And I'm Greg Collins. Welcome to Simulectics Radio.
Rachel Foster
Tonight we're exploring the construction of the core self—that fundamental sense of being a conscious agent situated in a body, experiencing the present moment. This is the layer of selfhood that emerges before language, before autobiography, yet it forms the foundation upon which all subsequent identity is built. The question we're examining: how does the brain generate the subjective experience of being someone?
Greg Collins
It's a question that sounds almost mystical until you start looking at the neural architecture. The brain doesn't passively receive a self that exists independently. It actively constructs the experience of selfhood through specific computational processes. When those processes are disrupted—through injury, drugs, or pathology—the sense of self fragments in predictable ways.
Rachel Foster
Joining us to explore these mechanisms is Dr. Michael Graziano, professor of neuroscience at Princeton University and author of 'Rethinking Consciousness.' His work on attention schema theory offers a compelling account of how the brain builds models of its own awareness. Dr. Graziano, welcome.
Dr. Michael Graziano
Thank you for having me.
Greg Collins
Let's start with the basic framework. You've argued that consciousness is essentially the brain's model of its own attention. Can you unpack that?
Dr. Michael Graziano
The core idea is that the brain builds models of everything it needs to control. It models the body's position in space—that's proprioception. It models other people's mental states—that's theory of mind. And it models its own process of attention. That internal model is what we experience as consciousness. It's a simplified, schematic representation that allows the brain to monitor and regulate its own information processing.
Rachel Foster
So consciousness is a kind of self-monitoring system. But that seems to leave out the subjective quality—the what-it's-like-ness of experience. When I'm aware of being aware, there's something it feels like to be me in this moment. How does a computational model account for that phenomenology?
Dr. Michael Graziano
The phenomenology is part of the model. When the brain constructs an attention schema, it doesn't just represent that attention is happening—it represents attention as a non-physical essence, a mental possession of information. That's the subjective quality. The model depicts awareness as something mysterious and immaterial because it's a simplified representation that leaves out the physical mechanisms. The brain doesn't need to model its own neurons firing to effectively control attention.
Greg Collins
That's a deflationary account of qualia. You're saying the feeling of subjective experience is essentially an information-processing illusion—or more precisely, a useful simplification that the brain makes about its own operations.
Dr. Michael Graziano
I wouldn't call it an illusion exactly. The model is real, and the consequences are real. When you report being conscious, you're reporting on the contents of this internal model. The model just doesn't include all the mechanistic details. It's like how your visual system models objects as having continuous surfaces even though the retinal input is fragmentary. The model is accurate enough for practical purposes.
Rachel Foster
But there's a leap from modeling attention to experiencing selfhood. Attention can shift between different objects, different thoughts. The self feels more stable than that—more like a persistent subject that remains constant even as the objects of attention change. How do we get from momentary awareness to the enduring I?
Dr. Michael Graziano
That's the core self as opposed to the autobiographical self. The core self is the sense of being a locus of experience in the present moment. It emerges from the brain's representation of the body and its relationship to the immediate environment. There are specific brain regions—the insula, the anterior cingulate cortex—that integrate information about internal bodily states with external sensory input. That integrated representation creates the feeling of being embodied, of being here now.
Greg Collins
The insula is particularly interesting. It receives input from the viscera—heart rate, gut sensations, respiratory rhythm. When people have damage to the insula, they often report feeling detached from their bodies, like they're observing themselves from outside. The sense of being a physical self seems to require constant updating from interoceptive signals.
Rachel Foster
I've worked with patients experiencing depersonalization, and that's exactly how they describe it—watching themselves from a distance, feeling like they're not quite real. But the autobiographical memory is intact. They know who they are in a narrative sense, but the feeling of being that person is absent. It's as if the core self has come unmoored.
Dr. Michael Graziano
Depersonalization is a great example of how the different layers of self can dissociate. You can lose the feeling of embodied presence while retaining cognitive knowledge about your identity. That tells us these are separate processes that normally integrate but can be disrupted independently.
Greg Collins
Let's talk about agency—the sense that I am the author of my actions. That seems central to selfhood, yet the neuroscience suggests most of our behavior is generated unconsciously, with the conscious sense of willing coming after the fact. How do you square that with the subjective certainty of being an agent?
Dr. Michael Graziano
The feeling of agency is another constructed model. The brain doesn't have direct access to the causal chain that produces behavior. Instead, it builds a simplified model that says: I intended this action, therefore I caused it. That model is usually good enough for social coordination and self-regulation. But the experiments showing that unconscious processes initiate action before conscious awareness catches up reveal that the model is a post-hoc reconstruction, not a real-time readout.
Rachel Foster
That has troubling implications for moral responsibility. If the sense of authorship is a retrospective story the brain tells itself, what does that mean for accountability? Can we hold people responsible for actions they didn't consciously choose in the moment?
Dr. Michael Graziano
The question of free will is thorny, but I think the attention schema framework helps. Even if conscious will is a constructed model, it's a model that influences future behavior. When you become aware of having made a choice, that awareness gets incorporated into your planning systems and affects subsequent decisions. The model has causal power even if it's not the ultimate source of action. Responsibility makes sense as a social construct that shapes behavior through that feedback loop.
Greg Collins
So we're responsible for our models of ourselves, not for some uncaused free will. The self is a control system that can be held accountable because accountability changes the system's future behavior.
Rachel Foster
But doesn't that reduce personal identity to a kind of useful fiction? If the core self is just a model the brain constructs for regulatory purposes, what happens to the intuition that I am genuinely something, not just the brain's representation of something?
Dr. Michael Graziano
I think that intuition is itself part of the model. The brain represents the self as having a kind of essential existence because that's the most efficient way to encode it. You don't need to represent all the underlying machinery to use the representation effectively. The mistake is thinking the map is the territory—confusing the model of selfhood with some separate metaphysical entity.
Greg Collins
This connects to the Default Mode Network, which shows increased activity during self-referential thought—thinking about your own traits, your past, your future. When that network is disrupted, people report decreased sense of self. The DMN seems to be where the brain maintains the ongoing model of who you are.
Dr. Michael Graziano
Exactly. And what's interesting is that the DMN isn't just passively representing the self—it's actively constructing it moment to moment. The sense of being a continuous person requires constant reconstruction. When you wake up each morning, your brain has to rebuild the model of who you are from memory traces. The continuity is an achievement, not a given.
Rachel Foster
That reconstruction process is vulnerable to disruption. I've seen patients with severe memory impairment who lose the thread of their own identity because they can't maintain narrative continuity. Each moment is isolated, and without memory to link moments together, the autobiographical self dissolves.
Greg Collins
But the core self can persist even without autobiographical memory. Patients with dense amnesia still have the sense of being embodied, of existing in the present. They've lost the story of who they are but not the feeling of being someone.
Dr. Michael Graziano
That's the distinction between the layers of self. The core self is more primitive and more resilient. It's built into the basic architecture of how the brain represents its relationship to the world. The autobiographical self is more fragile because it depends on intact memory systems and narrative coherence. You can lose one without losing the other.
Rachel Foster
What about development? Infants presumably have some rudimentary core self—they respond to their own name, they have preferences—but the full autobiographical self emerges later. How does that developmental trajectory map onto the neural architecture?
Dr. Michael Graziano
The infant brain is already building models of attention and embodiment, but those models are much simpler. As the cortex matures and language develops, the child gains the ability to construct more complex representations of self over time. The emergence of episodic memory around age three or four is crucial because that's when you can start linking experiences into a continuous narrative. Before that, there's a core self but not yet a robust autobiographical identity.
Greg Collins
And that maps onto what we know about childhood amnesia—most people can't recall events from before age three because the neural systems for encoding autobiographical memory aren't yet mature. The self that remembers its own past is a later developmental achievement.
Rachel Foster
We're running short on time, but I want to ask about the boundaries of self. If the core self is a model constructed by the brain, where does that model end? Are tools, prosthetics, or even other people sometimes incorporated into the self-model?
Dr. Michael Graziano
Absolutely. The brain is remarkably flexible about what it includes in its body schema. People with prosthetic limbs often report that the prosthesis feels like part of their body after extended use. Expert tool users show neural integration of the tool into their body representation. And there's even evidence that close social bonds—parent-child, romantic partners—create partial merging of self-other representations. The boundaries of self are permeable and context-dependent.
Rachel Foster
That plasticity is both fascinating and unsettling. It suggests the self is far more fluid than our subjective experience suggests.
Greg Collins
Which brings us back to the central insight—the self is a construction, not a discovery. The brain builds it, maintains it, and revises it as needed.
Rachel Foster
Dr. Graziano, this has been illuminating. Thank you for joining us.
Dr. Michael Graziano
My pleasure. Thank you both.
Greg Collins
That's our program for tonight. Until next time, question your assumptions.
Rachel Foster
And examine the observer. Good night.