The brain is our most important organ. It is the control center for the body and the carrier of personality. Brain research investigates on the one hand the functioning of the brain, and on the other hand its role in our perception, feelings and thought processes.
An estimated 100 billion nerve cells (neurons) communicate with each other via 100 trillion synapses. The neurons and the synapses - connection points through which information is transferred from nerve cells to other cells - form a huge network in which information is shifted and generated.
Brain functions are distributed among four areas, of which the cerebrum is the most important. This is where the centers for vision and speech are located, and thinking is also essentially a function of the cerebrum. The diencephalon controls the autonomic nervous system, the part of the nervous system that controls vital organ functions.
The cerebellum is mainly responsible for the coordination of the body. The brain stem controls elementary reflexes, such as yawning or breathing and heartbeat. Developmentally, the brain stem is the oldest part of the brain.
To uncover the secrets of the brain, brain researchers measure which parts of the brain become particularly active under which circumstances.
One important imaging technique is functional magnetic resonance imaging (fMRI), a special form of conventional MRI. The subject lies in a long tube in which a magnetic field is generated. In fMRI, researchers also measure the oxygen content of the blood in the brain. This allows them to visualize how and where the brain is currently working.
For example, if the subject raises a hand, a certain brain region becomes active. With the help of the fMRI images, the scientists can identify which areas of the brain are affected in diseases such as Parkinson's, Alzheimer's or after a stroke. These findings can help develop therapies.
In magnetoencephalography (MEG), researchers use sensors to measure the fine electrical activity of nerve cells in the brain. The resulting images allow them to see how much strain is being placed on certain parts of the brain. In this way, increased activity in the brain can be localized.
Even though the underlying technology of such measurement procedures is highly complicated, even simple experiments show which areas of the brain are used for certain tasks.
Thus, it can be quickly determined whether a subject develops strong feelings during an experiment, whether he imagines pictures or has to think a lot. Some measurements yield such clear results that scientists can harness the measured currents.
This makes it possible to control a computer via thought commands: Sensors measure, for example, the brain activity that occurs as soon as the subject imagines a certain movement, and implement this impulse - for example, to move a cursor on the monitor or to control devices.
This technology is being developed to enable people with disabilities to communicate with their environment using imaginary commands alone.
Despite such experiments, however, science is far from being able to read out the content of our consciousness. How the brain functions as an organ is completely different from how we perceive ourselves, how we think and feel.
In the brain itself there are no pictures or colors, but like in a computer only certain switching states. A certain neuronal state can be imagined as a photo on which all activities of all neurons at a certain point in time are mapped.
There is no obvious connection between this neuronal state and a simple experience of consciousness, such as a color sensation.
It is true that most brain researchers assume that, in principle, the contents of, for example, an imagined picture can also be recognized from the outside. But even if we were technologically capable of doing so, we would not be able to describe what we feel in the process.
So even if we were able to understand and describe all the processes in the brain, we would not be able to fully explain the way we perceive things.
The gap between measured brain activity and the experience of the actual thought process remains unbridgeable even for brain research. Nevertheless, brain researchers agree: Everything we experience, perceive and think is a result of the brain's activities.
The more precisely researchers know the centers of brain activity, the more diversely they can act on them. This applies primarily to neuronal diseases in which certain areas of the brain are damaged.
For example, scientists at the Ruhr University in Bochum succeeded in refining the sense of touch simply by using a special magnetic coil: they stimulated the part of the brain responsible for this motor segment by applying a magnetic field from the outside. After just a few sessions, the scientists were able to measure an improvement in fine motor skills.
This type of external stimulation, called transcranial magnetic stimulation, is used for diseases of the nervous system: for example, multiple sclerosis and Parkinson's disease and mental illnesses such as depression and schizophrenia.
Brain researchers are also coupling the imaging techniques with artificial intelligence. With the help of these two technologies, they hope to predict in the future how diseases such as Parkinson's will progress in patients.
But even for healthy people, there may be a number of applications from brain research in the future that could simplify or improve daily life. One vision for the future is that brain scans will help us better understand how we learn and process information.
But whether more complex knowledge or skills can ever be implemented at the push of a button is questionable. In theory, there is nothing to be said against this if we understand the brain's code more precisely. After all, such visions also make brain research one of the most exciting scientific fields of our time.
