Mind Matters News and Analysis on Natural and Artificial Intelligence

Brain hacks

Do we understand the brain better if we see it as a computer?
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Many researchers and science writers seem to think so. Just recently, we were told that recent research shows that differences between human neurons and those of other species “may contribute to the enhanced computing power of the human brain”:

Using hard-to-obtain samples of human brain tissue, MIT neuroscientists have now discovered that human dendrites have different electrical properties from those of other species. Their studies reveal that electrical signals weaken more as they flow along human dendrites, resulting in a higher degree of electrical compartmentalization, meaning that small sections of dendrites can behave independently from the rest of the neuron…

“It’s not just that humans are smart because we have more neurons and a larger cortex. From the bottom up, neurons behave differently,” says Mark Harnett, the Fred and Carole Middleton Career Development Assistant Professor of Brain and Cognitive Sciences. “In human neurons, there is more electrical compartmentalization, and that allows these units to be a little bit more independent, potentially leading to increased computational capabilities of single neurons.” “Electrical properties of dendrites help explain our brain’s unique computing power” at ScienceDaily

It gets better: From the same research we learn, “Each of our brain cells could work like a mini-computer, according to the first recording of electrical activity in human cells at a super-fine level of detail:

Compared with mice, the dendrites of human neurons turn out to have fewer ion channels, molecules studded in the cell’s outer membrane that let electricity flow along the dendrite.

While this might sound bad, it could give greater computing powers to each brain cell. Imagine a mouse neuron: if a signal starts down one dendrite, there are so many ion channels to conduct electricity that the signal will probably continue into the main trunk of the neuron. In a human neuron, by contrast, it’s less certain that the signal will conduct into the main trunk: whether it does will probably depend on activity in other dendrites, says Harnett. Clare Wilson, “Your brain is like 100 billion mini-computers all working together” at New Scientist

The researchers are suggesting, it seems, that we are smarter than mice because our neurons have more independence. One wonders, would a mouse whose neurons had more independence be smarter, or just dysfunctional?

Seeing the brain as a computer doesn’t tell us as much as we might think. When human beings build computers, we design them in a way that we can understand and use. So we think our brains must be like that too. Sure enough, in the vast complexity of our brains, we can surely find some elements that remind us of a computer. Others won’t.

And the mystery of human consciousness floats above it all, untouched…

Faced with the fact that human intelligence and consciousness is unique in our world, in recent years, researchers have come up with a remarkable variety of ad hoc explanations, whole or partial, for how it came to exist. The explanations usually center on claims about the evolution of the human brain. “The brain is a computer” is especially popular just now but many others are on offer.

Recently, researchers informed us that starchy food may have aided human brain development. We’ve heard similar claims for meat. and cooked food in general. As of 2014,

Some say we evolved large brains alongside small guts, but another research team found no such correlation. Alternatively, fluid societies (relative to chimps) explains it. And, according to some, mental illness helped. Chimpanzees’ improved skills throwing excrement are also said to provide hints about human brain development. (The ability to throw projectiles at very high speeds is apparently unique to humans.) Our ancestors had to grow bigger brains anyway, we are told, to make axes and hunt something besides elephantsCollective intelligence (“ideas having sex”), whatever that means, has been really important to human evolution as well.
Denyse O’Leary, “Human Origins: The War of Trivial Explanations” at Evolution News & Science Today

Amid all the speculation, we’re not even sure how important brain size is. We learn variously that social challenges decreased our brain size, that large brains helped Neanderthals to go extinct, and that Homo naledi’s small but sophisticated brain challenges belief in “an inevitable march towards bigger, more complex brains.” There doesn’t seem to be a thread here.

One constant theme does run through all these stories, however: Researchers seek a way that the human brain evolved immaterial consciousness as a mere fluke of evolution. But the sheer number of flukey explanations offered makes it seem increasingly unlikely that the development was an accident at all.

One might wonder, in that case, why researchers who are looking for a purely natural, material cause of human intelligence and consciousness keep adding to the stack. One problem is that more daring approaches to the problem are even less likely.

Daniel Dennett

Philosopher Daniel Dennett insists that consciousness is an evolved illusion but, if so, science is grounded in an illusion. Another philosopher, Bernardo Kastrup holds that human consciousness is simply a dissociated fragment of the universal consciousness of all life forms.

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Bernardo Kastrup

Panpsychist philosophers like Philip Goff argue that all particles are conscious: “Panpsychism is crazy, but it’s also most probably true.” How can it probably be true? Because all these philosophers deny that human beings are unique and that human consciousness is immaterial. Dennett and Kastrup seek an explanation for human consciousness that would apply equally to a gorilla and an amoeba. Goff applies it to a coffee mug as well, for a fully naturalist universe. In that scheme, a computer would, of course, be conscious, just like the coffee mug, at least to the extent that it is an assemblage of particles that are held to be conscious.

So, in the end, we may be able to use a computer image to explain some aspects of how our brains work, but the idea will not really bear much more weight than that. It will, however, give rise to many pop science stories, easy to write and read but not very informative in the long run.

See also: Reconciling mind with materialism twenty-five years on

Do big brains matter to human intelligence?

and

The brain is not a meat computer (Michael Egnor)