Where Consciousness Lives in the Brain — The Posterior Hot Zone, Neural Correlates, and Stranded Minds | Chapter 6 of Then I Am Myself the World

Chapter 6 of Then I Am Myself the World: What Consciousness Is and How to Expand It by Christof Koch turns from metaphysics to biology, asking one of the most foundational questions in neuroscience: Where in the brain does consciousness arise? Koch retraces the scientific history of the search for the Neural Correlates of Consciousness (NCC), outlines decades of research conducted with Francis Crick, and synthesizes modern evidence pinpointing a specific region—the posterior neocortex—as the likely home of conscious experience. The full chapter video summary is included below to deepen your understanding of these ideas.

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From Heart to Brain: A Historical Shift

For most of human history, the heart—not the brain—was believed to be the seat of thought, emotion, and consciousness. Koch explains that only in the last few centuries did Western science shift toward a brain-centered understanding of the mind. This shift accelerated dramatically with the rise of neuroscience, clinical neurology, and technologies like EEG, fMRI, and electrical stimulation.

Today, a consensus has emerged: somewhere within the brain lies the physical substrate of experience. But which regions matter—and which do not?

The Posterior Hot Zone: A Likely Source of Conscious Experience

Based on decades of research, Koch argues that the posterior neocortex—often called the posterior hot zone—is the most reliable neural correlate of conscious experience (NCC). This region includes:

• Occipital cortex
• Posterior parietal cortex
• Posterior temporal cortex

These structures are known to support sensory perception, imagery, spatial awareness, and the representation of self. When activity in these areas is disrupted—through lesions, strokes, or anesthesia—conscious experience fades or disappears entirely.

By contrast, when these regions are stimulated electrically, patients often report vivid perceptual or emotional experiences. This strong bidirectional link between stimulation and experience is key to identifying the NCC.

Why Not the Frontal Lobes?

Popular culture often frames the prefrontal cortex as the “center of the mind,” but Koch emphasizes that the evidence does not support this when it comes to consciousness. The prefrontal cortex is involved in:

• Decision-making
• Planning
• Cognitive control
• Working memory

But patients with major prefrontal damage often remain conscious. What changes is their behavior, judgment, and social functioning—not the presence of subjective experience.

This distinction is critical: cognition is not consciousness.

The Cerebellum: Highly Complex Yet Not Conscious

One of the most surprising findings in neuroscience is that the cerebellum, despite containing three times more neurons than the cortex, does not contribute to consciousness. Patients with severe cerebellar damage retain full awareness and subjective experience.

Koch interprets this through the lens of Integrated Information Theory (IIT): although the cerebellum is highly complex, its architecture is modular and feed-forward, generating very little integrated information. Without integration, no consciousness arises.

Searching for Consciousness in Stranded Minds

The chapter highlights one of the most compelling challenges in clinical neuroscience: detecting consciousness in patients who cannot speak or move. Some individuals diagnosed as being in a vegetative state may still possess intact conscious experience.

To address this, researchers have developed the Perturbational Complexity Index (PCI), a technique that involves stimulating the brain with magnetic pulses and measuring the complexity of its response. High PCI scores indicate high integrated information—and therefore likely consciousness.

This technology has provided hope for identifying “stranded minds” who are aware but unable to respond externally.

Is Consciousness Exclusive to Humans?

Koch makes clear that consciousness is not restricted to humans. Many mammals, birds, and possibly even certain invertebrates possess the neural architectures required for integrated, subjective experience. IIT expands this framework by suggesting that any system with sufficient cause-effect structure could be conscious, regardless of species.

This has profound ethical implications for how society treats animals and how future neuroscience may assess artificial systems.

Anchoring Consciousness in Biology

This chapter grounds the study of consciousness in empirical neuroscience. While earlier chapters explored philosophical perspectives, Chapter 6 demonstrates that consciousness is not an abstract mystery floating above biology—it is woven into the brain’s physical structure.

By identifying where consciousness likely arises, Koch sets the stage for later chapters that examine how consciousness can expand, alter, dissolve, or intensify in different physiological states.

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Chapter 6 provides a crucial biological anchor for understanding consciousness. To explore these findings further, make sure to watch the video above and continue through the full series of chapter breakdowns.

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