Objection 3 Computers Cannot Explain The Mind Therefore The Brain Is Not A Computer
This one is tough because it is a thorny philosophical argument, and how one reacts to it depends on ones philosophical stances. Many philosophers have argued that purely mechanical accounts of the brain cannot account for the mind, and given that the definition of computer provided above is very much mechanical, it is true that if the mind cannot be accounted for by purely mechanical means, then there must be something missing when I say the brain is a computer.
Ultimately, as I noted in the introduction, I do not have time to contend with the long debates on this issue in philosophy of mind and cognitive science here. All I will say, is that I personally find all of the philosophical objections to the idea that the mind can arise from mechanical processes unconvincing. Whether its Searles Chinese Room Argument, Chalmers zombies, or Jacksons Mary the Scientist, Ive never been persuaded that theres anything really worthy of serious consideration for neuroscientists in these thought experiments. Im much more convinced by the works of philosophers like Daniel Dennett and Patricia Churchland, who seem much more clear-eyed and logical to me. But hey, thats my perspective. If someone rejects the idea that the mind can be reduced to physical mechanism, then I recognize that my arguments above are unconvincing. But, anyone who is comfortable with reductionism, and who understands the definitions above, should also recognize that the brain is a computer by definition.
Is Your Brain A Computer
We asked experts for their best arguments in the long-standing debate over whether brains and computers process information the same way.
Its an analogy that goes back to the dawn of the computer era: ever since we discovered that machines could solve problems by manipulating symbols, weve wondered if the brain might work in a similar fashion. Alan Turing, for example, asked what it would take for a machine to think writing in 1950, he predicted that by the year 2000 one will be able to speak of machines thinking without expecting to be contradicted. If machines could think like human brains, it was only natural to wonder if brains might work like machines. Of course, no one would mistake the gooey material inside your brain for the CPU inside your laptopbut beyond the superficial differences, it was suggested, there might be important similarities.
Today, all these years later, experts are divided. Although everyone agrees that our biological brains create our conscious minds, theyre split on the question of what role, if any, is played by information processingthe crucial similarity that brains and computers are alleged to share.
This story was part of our September 2021 issue
We asked the experts to tell us why they think we shouldor shouldntthink of the brain as being like a computer.
AGAINST: The brain cant be a computer because its biological.
None of that has any resemblance to what goes on in your brain, says Richards.
Quantum Theories Of The Mind
As these kinds of questions still loom large and unanswered, several high-profile scientists have come to speculate if quantum effects might be necessary to explain what is going on in the brain.
As has been clear since the 1930s, quantum theory is non-local. In entangled quantum systems, part of the information lives in the entanglement itself, which is not stored locally. As consciousness appears to us as a unified, non-local field it is hard for us to imagine it coming from billions of individual neurons, which makes it tempting to draw the conclusion that consciousness could arise from or be connected to quantum effects. But keep in mind that this is as of yet merely a metaphorical statement: it does in no way necessitate that the binding problem can only be explained by the non-locality of quantum theory.
Beck and Eccles propose that consciousness might influence exocytosis, the process by which cells transport molecules like neurotransmitters across cell membranes, through conscious intentions. Further work has built on their theory recently, proposing which protein mechanism might be involved.
Another famous controversial example is Penroses and Hammeroffs Orch OR theory, which postulates how quantum states are reduced within the neurons by so-called microtubules. The theory is rather complex and would go beyond the scope of this article . It has been much debated and probably doesnt hold, but is nevertheless an interesting impulse.
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The Future Of Bcis: Problems And Prospects
Brain-computer interface research and development generates tremendous excitement in scientists, engineers, clinicians, and the general public. This excitement reflects the rich promise of BCIs. They may eventually be used routinely to replace or restore useful function for people severely disabled by neuromuscular disorders they might also improve rehabilitation for people with strokes, head trauma, and other disorders.
At the same time, this exciting future can come about only if BCI researchers and developers engage and solve problems in 3 critical areas: signal-acquisition hardware, BCI validation and dissemination, and reliability.
Neural Networks: Is Your Brain Like A Computer
About three years ago, when I was expecting my son, a friend gifted me a copy of Lise Eliots Whats Going on in There?. It was a very welcome deviation for me from all the parenting books that insisted on telling me how my life was about to turn into living hell with sleepless nights, exhaustion and a general lack of sanity. So I started perusing through the book and soon realized that it was the single most important thing I read in preparation for my impending parenthood. The book talks about brain development in humans from birth until early childhood. Its a fascinating subject in itself, but was even more so in the context of Artificial Intelligence.
Neurobiologically, a human brain functions through a network of neurons or nerve cells that interact with each other to communicate and process information based on which we see, hear, move, think, make decisions and generally function. The central nervous system and its network of neurons are at the heart of all the activity that happens in the body.
If we break it down, the human body functions very similarly to modern day computers or rather, computers are very closely aligned to the most complex processing unit there has ever been, namely the human brain. Going back to basics for a moment any information processing system consists of 5 main components input, output, storage, processing and program. We can draw parallels between the brain and computers for each of these elements.
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Zombie Brains Are A Thing
There is life after death if youre a pigsorta. Image source: Wikimedia Commons)
Recently at the Yale School of Medicine, researchers received 32 dead pig brains from a nearby slaughterhouse. No, it wasnt some Mafia-style intimidation tactic. Theyd placed the order in the hopes of giving the brains a physiological resurrection.
The researchers connected the brains to an artificial perfusion system called BrainEx. It pumped a solution through them that mimicked blood flow, bringing oxygen and nutrients to the inert tissues.
This system revitalized the brains and kept some of their cells alive for as long as 36 hours postmortem. The cells consumed and metabolized sugars. The brains immune systems even kicked back in. And some samples were even able to carry electrical signals.
Because the researchers werent aiming for Animal Farm with Zombies, they included chemicals in the solution that prevented neural activity representative of consciousness from taking place.
Their actual goal was to design a technology that will help us study the brain and its cellular functions longer and more thoroughly. With it, we may be able to develop new treatments for brain injuries and neurodegenerative conditions.
Mental Illness And The Broken Brain
Understanding that mental illness, such as depression, is an organic disease can help people seek treatment. Accepting that you have a medical condition is easier than accepting that you have a moral defect. Nonetheless, the cerebral mystique can also cause people with mental illness to believe themselves broken people, incapable of recovery. Sometimes this self-stigmatization can be harder to fix than people who believe themselves morally flawed. Focusing on the brain ignores cultural and environmental factors, as well as non-physical therapies.
General paresis of the insane, a diagnosis which was once applied to a large fraction of the people admitted to an asylum, was treated as a mental disease until the early 20th century when it was shown to be caused by advanced syphilis. This is a clear example of a mental disease of biological origin outside of the brain acting through the brain by the degeneration of neurons, but not caused by the brain. It is a brain disease, a biological sickness, and an environmental condition simultaneously.
Some mental diseases such as schizophrenia have a large heritable component others such as major depression do not. Other conditions such as bipolar disorder and anorexia nervosa have intermediate values. Often environmental factors are triggers or reinforce existing conditions. There seems to be a correlation between schizophrenia and urban living.
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Difference Between Brain And Computer
The differentiation between brain and computer is very useful in the field of cognitive science and artificial intelligence where the human brain is used to model the artificial neural network to create an expert system. The prior difference between the brain and the computer is that the brain can work without data, but computers require a minimum amount of data. A brain is an innovative and creative organ, but the computer cannot create a new thing without any support, it would need some program or software to do this. The brain also has common sense reasoning and understanding capabilities.
Does The Braim Have An Operating System
Many years ago, there was a candy vending machine where I worked. For health reasons, I needed to avoid being tempted by its offerings. One day, passing the machine on my way from my office to the mens room. I was strongly tempted because one of my favorites, chocolate with almonds, had just become available. I resolved to resist the temptation and thought no more about it. As I walked back to my office from the toilet, thinking about a mathematical problem, I noticed that I was eating that delicious candy bar with no memory of having bought it.
This story can be conceptualized as a struggle among three brain processes, we may call: EatTheSweet, EatHealthy, and DoMath. EatHealthy executes and stops EatTheSweet. Then later, while DoMath is going at full blast, EatTheSweet sees its chance and executes. What controls this? In a computer, it would be the operating system that allocates resources to processes and permits them to execute. One can certainly imagine that the multitasking brain possesses some such mechanism controlling its hundreds of processes, some struggling for attention and resources. But an operating system needs a user interface. And where and what is the user?
Relationship To Embodied Cognition
Current advances in artificial intelligence, buoyed by improvements in computing speed, big data, and neural networks, have demonstrated many achievements beyond human abilities, but they are far from demonstrating human understanding.
AI models may have gone beyond human performance on a language understanding benchmark, but could such a model pass a medical licensing exam? If it could, would you trust it to be a doctor? To be a doctor requires understanding a patient which means you need to have an implicit understanding of other people and the surrounding environment.
The human body evolved to deal with specific risks and opportunities in the world around it. A just born baby already has pre-existing reflexes such as sucking what comes into its mouth, or holding things in its hand. It is prepared to recognize faces. It directly differentiates sound and noise. It already has assumptions about a world of possible predators or nurturers. Babies are not born with rules on how to make representations of the world, or the ability to manipulate information. Their brains are not general-purpose computing engines.
Heres Why Well Never Be Able To Build A Brain In A Computer
People often describe the brain as a computer, as if neurons are like hardware and the mind is software. But this metaphor is deeply flawed.
A computer is built from static parts, whereas your brain constantly rewires itself as you age and learn. A computer stores information in files that are retrieved exactly, but brains dont store information in any literal sense. Your memory is a constant construction of electrical pulses and swirling chemicals, and the same remembrance can be reassembled in different ways at different times.
Brains also do something critical that computers today cant. A computer can be trained with thousands of photographs to recognise a dandelion as a plant with green leaves and yellow petals. You, however, can look at a dandelion and understand that in different situations, it belongs to different categories. A dandelion in your vegetable garden is a weed, but in a bouquet from your child, its a delightful flower. A dandelion in a salad is food, but people also consume dandelions as herbal medicine.
In other words, your brain effortlessly categorises objects by their function, not just their physical form. Some scientists believe that this incredible ability of the brain, called ad-hoc category construction, may be fundamental to the way brains work.
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Objection 6 These Definitions Are Useless And Potentially Misleading
This objection is potentially valid. As I noted, the technical definitions of computer and algorithm are so abstract that they can be applied to everything in the universe. As I argued above, I think its reasonable to restrict their usage to machines, like the brain, that not only solve the functions of physics, but a much larger array of computable functions, potentially even all of them . But, what do we achieve by applying the words computer and algorithm to the brain? How does that help us to understand the brain, given that the formal definitions are mechanism agnostic? If many people do not know these formal definitions, and they think that computers are Von Neumann architecture machines and algorithms are discrete step-by-step instructions for Von Neumann architecture machines, then we run the risk of grossly misleading these people when we use these words in relation to the brain. My response to this objection is twofold.
First, there are many terms that scientists use formal definitions for, but which many people misuse. For example, the term significant means something very specific in statistical hypothesis testing, even though its usage in common language means anything thats big, meaningful, or impactful. Should we stop using the term significant, then? I dont think so. I think we merely need to be careful to articulate clearly to people what we mean when we use this word.
The Buts Of The Brain
The reductionist schools have compared the mind with a computer, and perception and action with the sensors and effectors that connect that formal mind with the changing physical world. This metaphor has been so successful that today it seems only natural to think that way. For example, the possibility that is frequently discussed in cyberpunk of âraising our awareness to the cloudâ encapsulates the dualism between an abstract and immaterial mind and a physical body that is completely irrelevant. Another example of this reductionist focus is the consideration of the eye as a camera, and not as an organ in constant development, structurally and functionally plastic, context-dependent and integrated in the perceptive system of an organism that actively and intentionally explores its environment.
designerSo the metaphor affords us simple but also simplistic solutions, and renders the most fundamental properties of living organisms invisible.
How can we scientifically explain organisms and their behaviors with scientific rigor but without reducing them to a mere mapping of inputs and outputs? What defines an organism from the approach of Ecological Psychology is the particular way in which structure and function are interlinked to interact adaptively with the environment.
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Objection 4 Brains Can Implement Non
This is a very interesting argument that has been advanced by various people. The physicist Roger Penrose has claimed that humans have various insights and behaviours that require non-Turing computation and quantum effects for explanation. Like Dennett, I consider Penroses claims questionable. Its not clear from scientific evidence that human behaviour requires any radical rethinking of computation or physiology.
But, there are other more serious attempts in this vein. Notably, Hava Siegelmann, who provided one of the proofs that recurrent neural networks are Turing complete, also published an article in Science in which she argued that recurrent neural networks can, in fact, be super Turing. This means that they can solve the set of computable functions and more, i.e. they can implement algorithms that Turing machines cannot. Its a very interesting result. I will admit that I find Siegelmanns proof in that paper hard to understand, so I prefer to remain agnostic as to whether this is an accepted fact.
But, for arguments sake, lets say that Siegelmanns proof is correct, and that recurrent neural networks are super Turing. That would suggest that brains are also super Turing. If the space of possible brains is super Turing, then someone, someday, could engage in computations that no laptop could ever do. In that case, arguably, the brain is not just a computer, its a super computer. This would only make my case that the brain is a computer stronger.