How Does the Brain Know Itself?

"Before any high-level narrative of selfhood can form, the brain must continuously register what is happening inside the organism—the heartbeat, the gut, the slow thrum of visceral state. This is interoception, mediated primarily through the insula. Neuroanatomist A.D. Craig proposed a hierarchical model in which the posterior insula maps raw sensations—pain, temperature, organ state—and then, through successive integrations, these become higher-order emotional representations in the anterior insula."

"The visceral substrate of selfhood is not an add-on to cognitive self-awareness; in many frameworks, it is its foundation. Neuroimaging shows the anterior insula co-activating with the medial prefrontal cortex during self-reflection: The body and the narrative are not cleanly separable."

"Being an interventional psychiatrist—watching people respond rapidly to treatments like transcranial magnetic stimulation, with measurable, specific mechanistic effects that translate directly into subjective experience—has only consolidated this stance. Interventions need to work, and we are best served when we understand exactly how."

The brain constructs self-awareness through hierarchical integration of bodily signals. Interoception, mediated by the insula, converts raw physical sensations—heartbeat, organ state, temperature—into emotional representations. The posterior insula maps basic sensations while the anterior insula processes higher-order emotional states. This visceral foundation is inseparable from cognitive self-awareness. The Default Mode Network, including medial prefrontal cortex and posterior cingulate, continuously updates autobiographical identity. Understanding these mechanistic relationships between objective neural processes and subjective experience requires coherent theory. Interventional psychiatry demonstrates this connection through treatments like transcranial magnetic stimulation, which produce measurable neural effects that directly translate into subjective experience changes.

Read at Psychology Today