Here are some reasons why they aren’t really the same:
1. Is the human brain unique in some way?
Yes, but not so much in its structure as in the things we do with it. For example, the human, mouse, and fly brains all use the same basic mechanisms, which is a bit of a puzzle, considering the different things we do with our brains. The human brain is bigger than most. But then lemurs performed as well as chimps on the primate cognitive test battery (a primate intelligence test) and lemurs only have brains that are 1/200th the size of chimps’ brains. So, what we humans are doing differently from lemurs and chimps doesn’t depend wholly on brain size either. One recent surprise for neuroscientists is that the white matter (connectome) in human brains is quite orderly, not the haphazard accumulations of aeons of evolution that the researchers expected. Another basic assumption has been that the brain operates like a series of switches. But most parts of the brain are involved in, for example, processing signals arising from touch. And that’s just the beginning. So we know that human thinking is different from animal thinking operationally but just how it comes to be different has not been found in the brain.
2. If the brain is so closely interconnected, wouldn’t people lose the ability to think if their brains were split in half or half cut away?
This surgery is done to treat severe epilepsy. The brain adapts to what it must work with and the patient usually suffers only minor disabilities. Roger Sperry’s Nobel Prize-winning split-brain research convinced him that the mind and free will are real. And yes, some people think and speak with only half a brain. Of course, where half of the patient’s brain has been removed due to serious epilepsy damage (that is now threatening the other half), that undamaged half (hemisphere) had probably been doing most of the work anyway. So our brains are both closely connected and yet highly adaptable. That adaptability is sometimes called neuroplasticity.
3. Can people in comas, who show no awareness of their surroundings, really think?
Yes! Modern neuroscience is shedding light on the minds of people in a persistent vegetative state (PVS)? The preferred new term is “disorders of consciousness.” For example, in one study, “Remarkably, five patients were able to wilfully modulate their brain activity, suggesting that, though unable to express any outward signs of consciousness at the bedside, they could understand and follow the researchers’ instructions.” Generally speaking, they can hear us: Researcher Adrian Owen found that brain wave patterns when asked to imagine something, were the same as those of normal volunteers. Can people in comas have abstract thoughts? Stoneybrook neurosurgeon Michael Egnor has some ideas about how we might test for that ability, using scrambled word sequences. Of course, if we are even asking, we are a long way from the “He is now just a vegetable” concept of old.
4. Is a brain really needed for thinking?
That’s a good question. At the animal level, maybe not. The “blob,” now on display at the Paris Zoo, engages in complex behavior without a brain. So does the flatworm and the amoeba and so do the many plant communications networks. One can fairly argue that they aren’t “really” thinking. But the conundrum around consciousness makes it difficult to say more than that they probably aren’t conscious, in the human sense, though many may be sentient (they feel things). Even a human being, as we saw above, can get by with surprisingly little brain or brain function and actually be conscious in the human sense.
5. Can we develop tests of the brain for consciousness?
Well, first, we aren’t really sure what consciousness is. A recent public access paper proposing various tests for consciousness reads like an ambitious but hopeless project that offers some genuinely interesting moments. For one thing, researchers are often limited by their assumptions: We are frequently informed that human consciousness developed so as to enable humans to hunt together more efficiently in groups. But wolves hunt efficiently in packs without requiring anything like that. Microorganisms and body cells hunt efficiently without any brain at all. That’s why consciousness is called a The Hard Problem. That is also one reason that the researchers can’t really give Sophia the Robot a mind. It’s not clear where they would start.
6. But wait. If the mind were real, wouldn’t we be able to control things by thoughts alone?
We do that now with our bodies. And we can do it under other circumstances too if an electrical connection can be established. Neurons can work with electrical signals from electronics. This is especially important for helping amputees and blind people. There are already promising results from a prosthetic hand controlled by thoughts alone and a mind-controlled robot arm that needs no brain implant. Orion, a device that feeds camera images directly into the brain via electrodes, bypassing damaged optic nerves, has enabled some vision in study participants. A vast amount of technical work remains to be done, of course. But, just as you control your natural hand by thoughts alone, electronics should, in principle, enable you to do that if you required a prosthesis.
7. Can brain scans read our minds?
They can — in a dozen conflicting ways. A recent study involving 70 research groups identified sharp limitations in the value of brain imaging (fMRI) in understanding the mind: “Simple task, simple hypotheses, unmissably big chunks of brain — simple to get the same answer, right? Wrong.” There is poor correlation between different scans even of the same person’s brain, experienced researchers say. That’s not to say the technology won’t improve. The main thing to see is that “reading the mind” is more like reading the ocean than like reading the directions on a package. We would need to begin by deciding exactly what we want to know—and then go fishing.
8. Aren’t computer programs being developed that think just like people?
No. There are a number of reasons why computer programs can’t and won’t think just like people. For our purposes here, the brain is not at all like a computer: Seeing the brain as a computer is an easy misconception rather than an informative image, says neuroscientist Yuri Danilov: “But as soon as you assume that each neuron is a microprocessor, you assume that there is a programmer. There is no programmer in the brain; there are no algorithms in the brain…” Nor is the brain billions of little computers: Much popular literature leaves the impression that living organisms are machines or even billions of them linked together. From a Google product manager: “The complexity and robustness of brain neurons is much more advanced and powerful than that of artificial neurons” and “the neurons in the brain are implemented using very complex and nuanced mechanisms that allow very complex non linear computations,” among many other things. He sees the brain mainly as a source of inspiration rather than a model. A clever programmer can develop a routine that sounds lifelike (see, for example, Sophia the Robot at AI Hype Countdown 4). But such ingenuity doesn’t give the robot a mind.
9. Don’t neuroscientists say that the mind is just the brain?
Many scientists believe that, not because of evidence, but because they are materialists. The evidence does not point in that direction. Thinking it through carefully, the idea doesn’t even make sense, as Michael Egnor points out: “How do we believe that there are no beliefs? If eliminative materialism is true, then their own belief in eliminative materialism isn’t a belief. It’s a physical state, a certain concentration of neurochemicals that we (the uninitiated) foolishly call a belief. So a disagreement between an eliminative materialist and a dualist isn’t really a disagreement at all. It’s just two different concentrations of brain dopamine or whatever. Exactly how these chemicals in different skulls get into a “disagreement” is left vague. At this point, you may get a bit uncomfortable, as you would if the guy you’re sitting next to on the subway starts talking about the fact that CNN is broadcasting directly into his brain.”
In fact, the mind’s reality is consistent with neuroscience. It’s not popular with neuroscientists but that is a different matter. Incidentally, the mind cannot just “emerge from” the brain if the two have no qualities in common.
10. Do any neuroscientists doubt the consensus that the mind is just the brain?
Yes, the great mid-twentieth century neurosurgeon Wilder Penfield offered three lines of reasoning for such doubts, based on brain surgery on over a thousand patients. A number of other neuroscience pioneers, some of them Nobel Laureates, arrived at that position due to their research. Here are four examples.
The view that the mind is simply what the brain does is not derived from evidence so much as from a prior commitment to materialism. The more we explore, the more we are likely to see that clearly.
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