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Are Lab-Grown Human Brains the Next Big Thing?

Neurosurgeon Michael Egnor thinks the hopes for humanly conscious lab-grown brains are faint indeed

A recent paper in Stem Cell Reports raises hopes, for some, of lab-grown human brains:

For the first time, a team carefully characterized the electrical chattering of neurons grown from a brain organoid and found that they spontaneously formed long-distance connections that allowed them to fire in synchrony. “Fire together; wire together” is a fundamental testament of learning in neuroscience. Because neurons in lab-grown minibrains can sync up their activity, analogous to how neurons hook up in our brains, it’s possible that the brain nuggets have the capability to support higher cognitive functions when they’re more mature…

How well the results translate to a full-grown mini-brain is anyone’s guess. But the sophistication of the flattened organoid threw the team off guard. Neurons not only formed long-distance connections, they also fired in synchrony while retaining their individual characteristic activity. What’s more, when treated with drugs that either amp up or tone down network strength, the culture responded in kind.

Shelly Fan, “Could Lab-Grown Brains Develop Consciousness?” at Singularity Hub

These “cerebral organoids,” which were later dissected, are thought to help researchers study human developmental disorders, as when “human brain blobs” were transplanted into mouse skulls (paper).

Fan acknowledges that many people will have qualms about this whole area. But, she says, “There’s a very un-sexy view of consciousness: our rich, meaningful inner experience of self and other is nothing but electrical and chemical chattering inside our brains.”

Franz Brentano (1838–1917)

Mind Matters News asked neurosurgeon Dr. Michael Egnor to comment:

The first problem with answering the question about whether a brain-in-a-lab can be conscious is: “What is consciousness?”

Of course, vague answers abound: rich interior life, self awareness, etc. But that’s jargon. We must define exactly what we mean, and use that definition, rather than referring vaguely to “consciousness.”

Franz Brentano (1838–1917) gave the best answer and it derives from the classical philosophers. Consciousness (i.e. the mental, as opposed to the physical) is intentional; that is, it is “about” something. The physical is never about anything. The mental is always about something.

Related to this, it was the opinion of Aristotle. and Thomas Aquinas. that everything in the mind begins in the senses. We do not and cannot have any thought without first having some sensation and perception, from which we extract imagination and reason.

On that view, brains-in-labs would need sensory organs. Without sensory organs, there is no raw material for intentionality, so no aboutness and no “consciousness.”

So my answer would be: Consciousness means that there is some power of the brain tissue in the lab that is intrinsically “about” something else (i.e. that is intentional) and neural tissue grown in a lab cannot have intentionality unless it has sense organs. If sense organs that function properly can be grown with the tissue, I don’t see any reason in principle to think that the tissue can’t have intentionality, in the same way, for example, that an animal does. Whether such a tissue can actually be achieved is another matter.

But such manufactured intentionality can only be about concrete things, not abstract things. I think that no “manufactured” intentionality can have abstract thought. That is spirit, created directly by God.

The article in Singularity Hub was careful to stress that there is no evidence yet of consciousness, by any definition, in the nurtured dissected brain tissues.


Also by Michael Egnor on the immaterial mind:

Show me the human clones Michael Egnor: If man is matter, and nothing more, man can be copied. If not, he can’t. If man can be copied by a wholly material process, I need to rethink things. If he cannot be, materialists need to rethink things.

Four researchers whose work sheds light on the reality of the mind The brain can be cut in half, but the intellect and will cannot. The intellect and will are metaphysically simple

Atheist psychiatrist misunderstands the evidence for an immaterial mind. Patients with massive brain damage were shown to have a mental life.

and

Materialism is an intellectual trap, out of which neuroscience needs to climb. Neurologist Steven Novella refutes himself. He first asserts that everything he knows is an illusion. Then he insists that his illusions slap him in the face with reality.


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Are Lab-Grown Human Brains the Next Big Thing?