How does our brain really work

Question to the brain

Answer from Ipke Wachsmuth, Senior Professor at the Center for Cognitive Interaction Technology at Bielefeld University:

Ever since it was discovered that the brain plays a special role in the body, it has been described using state-of-the-art metaphors. It was supposed to work like a mechanism, once like communicating tubes connected to body parts, once like a telephone switchboard and now like a computer.

It is fair to say that the brain is an information processing system, and so is the computer. But then the similarity is over. We can already see that in the different “talents” of the brain and the computer. We struggle with tasks that computers can do in a split second: multiplying large numbers, taking square roots. Conversely, it is very difficult to do things that are easy for us, such as planning actions or understanding language, to be implemented in computers.

The brain certainly doesn't work like a classic digital computer, in which all processing steps take place one after the other. In the brain there are always a lot of processes running in parallel and they are widely distributed over the whole brain. But in order to improve computers, researchers today are trying to recreate individual aspects of how the brain works in computers. For example in the form of artificial neural networks. These are programs that run in the computer and whose structure is copied from the connections between the neurons of the brain.

They are not programmed, but trained on examples, whereby the weighting of the connections between the components changes, similar to how the connections between neurons change. Artificial neural networks can learn and deal with incomplete information, e.g. recognize a face that is partially covered. In addition, they are more robust than the classic computer programs, they do not fail completely if a component is defective. There are also approaches, for example within the framework of the Human Brain Project, to build special computer chips in which the “firing” of the nerve cells of the brain is simulated with electrical capacitors.

Even so, the differences between the brain and the computer are still huge. In the brain, complex processing processes take place at the level of the individual cells, not just “firing” or “not firing”. In addition, the brain contains around a hundred different types of nerve cells, not just one. Another difference: the brain is always active, the cortex is largely concerned with self-generated activity, not just with signals that come from the sensory organs. The computer, on the other hand, links input with output, and if there is no input, it does nothing. Nevertheless, a brain can get by with an output of around 20 watts. The currently fastest supercomputer, on the other hand, needs 18 million watts. And for a supercomputer that can simulate the work of the human brain, you will have to build your own power plant.

But the most important thing is: a brain by itself does not work at all. It is an organ of the body with which it is closely and diversely networked. And everything we think, plan, recognize is accompanied by emotions. While evaluations can also be implemented in computers, it is still not understood how consciousness can arise from neural activity. So you can say: No, the brain doesn't work like a computer, but where the further development of computers is based on the human brain, the similarity increases.

Recorded by Manuela Lenzen

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Ipke Wachsmuth, Bielefeld University