Podcast Summary – New Books Network
Episode: Alan J. McComas, "Consciousness: The Road to Reductionism" (American Scientist, 2025)
Host: Gregory McNiff
Date: February 27, 2026

Episode Overview

This episode dives deep into one of the most intriguing questions in neuroscience and philosophy of mind: how neural activity gives rise to the sense of self. Host Gregory McNiff interviews Professor Alan J. McComas, author of the article "Consciousness: The Road to Reductionism," published in the March/April 2025 issue of American Scientist. McComas blends clinical insights, neurophysiology, and history to unravel the reductionist approach to consciousness, guiding listeners through scientific breakthroughs, philosophical challenges, and the most puzzling questions about free will and subjective experience.

Key Discussion Points & Insights

1. Defining Consciousness and Reductionism

• Multiplicity of Definitions: There are over 30 published definitions of consciousness; McComas uses “awareness of self” (03:10).
  • "Consciousness is an awareness of self. This is absolutely fundamental, and I think this was the first aspect, the first type of consciousness that evolved." – Alan J. McComas [03:15]
• Reductionism Analogy: Understanding consciousness is compared to understanding how a car works by breaking it into parts (radiator, engine, chemistry).
  • "People take consciousness for granted. But if I want to know how a car works, I'm going to probably start by opening up the hood..." [04:30]
• Historical Roots: Descartes’ dualism and Huxley’s automata lecture are foundational.
  • Descartes saw consciousness as a nonphysical agency acting on the brain (pineal gland).
  • Huxley posited consciousness as a mere byproduct, akin to a steam whistle on a locomotive, with no causal power.
    • "[Huxley] ended his talk by saying ... the consciousness of brutes ... is as completely without any powers of modifying that working as the steam whistle..." [10:43]
  • McComas disagrees: "I think Huxley was wrong, but we can go into that later on." [12:08]

2. Free Will and Neural Precedence

• Libet Experiments: Neural activity precedes conscious intention for action.
  • "What he showed was that the electrical activity in the brain ... actually began before the subject was aware of wanting to make the movement—that was extraordinary." [13:45]
• The Illusion of Free Will: We feel a sense of agency out of necessity, yet decisions are generated in the brain before conscious awareness.
  • "We don't really have free will. We have the illusion of free will. And that's very important... The illusion of free will is necessary for our sanity." [15:50]
• Role of Consciousness: Even if generated by neural activity, conscious images, memories, and 'internal voice' influence behaviors and choices.

3. Neuroscientific Techniques and Concept Cells

• Pioneering Thalamic Recordings (1960s): Single-neuron studies in awake Parkinson’s patients reshaped ideas about sensation and attention.
  • The brain doesn't easily filter out irrelevant sensory information at the thalamic level, contradicting expectations ([19:20]).
• The Power of Single Neuron Recordings: Deemed “the gold standard” for brain investigation by McComas, compared to the cruder spatial and temporal resolution of fMRI and EEG.
  • "When you get down to single cells, you know exactly what is happening. You know exactly where you are and whether it's being excited the cell, or whether it is not." [27:50]

4. Challenging Assumptions

• Difficulties Abandoning Dualism: Letting go of the idea of ourselves as more than biological machines remains the toughest paradigm shift.
  • "The most difficult by far is to accept that we really are machines, that we don't really have free will, that it's only an illusion. Even I find it difficult to accept that." [31:39]
• Animal Consciousness Is Easier to Accept: Observations of animal behavior and cognition (squirrels, dogs, cats, octopuses) provide compelling, relatable evidence.
  • "The squirrel had trained me to do that, not the other way around." [32:50]

5. The Role and Significance of "Concept Cells"

• Discovery in the Hippocampus: Single neurons fire for specific concepts regardless of modality (e.g., seeing or hearing “Jennifer Aniston”).
  • "It didn't matter what Jennifer Aniston was doing or wearing... The cell that was recorded from would fire impulses." [37:10]
• Linkage Between Memory and Consciousness: Concept cells bridge subjective awareness with neural mechanisms.
  • "For the first time, you knew that there were cells whose activity was very closely linked to consciousness. And we had never been in that situation before. ... I really think this was a game changer." [41:40]

6. Evolution and the Gradual Emergence of Consciousness

• Gradual Evolutionary Development: Consciousness likely emerged in small steps, gaining complexity over time, mirroring other evolutionary traits.
  • "I do believe ... that consciousness did, as it were, start off small and then become stronger with evolution." [44:15]
• Where to Draw the Line?: Behavioral sophistication in insects and small mammals muddies the division between conscious and non-conscious creatures.

7. The Reticular Activating System (RAS) and Wakefulness

• RAS as the Foundation of Consciousness: Enables wakefulness; without it, no consciousness is possible.
  • "To be conscious you have to be awake and it's the reticular formation that makes you awake..." [49:45]
  • Historically neglected but now recognized as crucial.

8. Critique of Non-Reductionist Theories

• Panpsychism & Quantum Theories: McComas dismisses claims that atoms or quantum effects explain consciousness.
  • "There's absolutely no evidence whatsoever for this... Let's at least make use of the evidence that we do have, like the concept cells." [53:00]

9. Wakefulness vs. Consciousness; Role of Memory

• Importance of Memory for Sense of Self: Mere wakefulness isn’t enough—memories integrate and ground self-awareness.
  • Example: The confusion of waking in a hotel room resolves with memory retrieval (55:42).

10. The “Hard Problem” Persists

• Qualia and Subjective Experience: Despite mapping neural correlates, science cannot yet explain how electrical activity becomes subjective feeling.
  • "There's still that last jump that has to be made to translate the impulse activity into the subjective experience. And I don't think anyone has any clue as to how that might happen." [57:34]
  • McComas views this as a likely “insoluble” phenomenon—potentially a brute biological fact.

11. Meaning and Dignity in a “Mechanistic” View

• Pragmatic Acceptance: Even if we’re mechanistic beings, it doesn’t diminish lived meaning—just as knowing how a piano works doesn't lessen the beauty of Chopin.
  • "No matter how our brains work, we can just put whatever is going on inside them to one side. We can forget about the mechanics and just enjoy life." [59:38]
  • "There's such beauty in [music]. I can't help but enjoy it. And I think that's what we have to do with consciousness. Unless we're philosophers, just forget about how it happens and just make use of it. Enjoy it." [60:54]

Notable Quotes & Memorable Moments

• “The illusion of free will is something which is very necessary to us. It's necessary for our sanity.” – Alan J. McComas [15:50]
• “The most difficult by far is to accept that we really are machines, that we don't really have free will, that it's only an illusion.” – Alan J. McComas [31:39]
• “Concept cells were concerned with the whole issue, not just the appearance, but also the name of whatever it was ... and I really think this was a game changer.” – Alan J. McComas [41:40]
• “There's still that last jump that has to be made to translate the impulse activity into the subjective experience. And I don't think anyone has any clue as to how that might happen.” – Alan J. McComas [57:34]
• “No matter how our brains work, we can just put whatever is going on inside them to one side. ... Unless we're philosophers, just forget about how it happens and just make use of it. Enjoy it.” – Alan J. McComas [59:38, 60:54]

Key Timestamps

• 01:53 – Motivation for the article, defining consciousness and reductionism
• 10:43 – Historical context: Descartes and Huxley’s views
• 13:45 – Libet experiments and the illusion of free will
• 18:53 – Significance of thalamic single-neuron recordings
• 26:15 – Superiority of single-neuron recordings over fMRI and EEG
• 31:35 – The hardest and easiest assumptions for the field to abandon
• 35:17 – Discovery and importance of concept cells
• 44:13 – Consciousness as a product of gradual evolution
• 49:45 – Role of the reticular activating system in consciousness
• 52:59 – Dualism vs. reductionism; critique of panpsychism and quantum theories
• 55:42 – Memory's role in the sense of self
• 57:04 – The hard problem: from nerve impulses to qualia
• 59:38 – Finding meaning and dignity as mechanistic beings

Conclusion

Alan McComas offers listeners a rich reductionist account of consciousness—grounded in historical, philosophical, and neuroscientific evidence. While maintaining a pragmatic stance on philosophical uncertainties, he asserts the necessity of both scientific rigor and everyday wonder, encouraging us to both investigate and enjoy consciousness, regardless of how mysterious its true mechanism remains.