What is the unconscious? Does it exist

Question to the brain

John- Dylan Haynes, Bernstein Center for Computational Neurosciences, Berlin: Only a very small part of the processes in the brain is conscious, but there is no serious scientific method with which one could name a percentage of which part of our brain processes is aware and which is not. A completely conscious process is inconceivable in the human brain. We cannot make ourselves aware of many unconscious processes by paying special attention - they cannot be reached by us. In contrast to the human brain, an artificial intelligent system could theoretically capture all “thoughts” and all associated background processes. Even so, it would not be clear whether this system has a consciousness. After all, anyone who simulates a black hole on a computer has not created any real attraction.

Conscious processes can become more and more automated over time and take place increasingly unconsciously. One example of this is driving a car: a novice driver has to laboriously operate the steering wheel, clutch and all gear levers and think about them consciously. An experienced driver, on the other hand, hardly ever thinks about what he is doing. Finding out whether these processes are really unconscious, however, is very difficult. Because as soon as we ask a person about this during an activity, he becomes aware of his actions. If researchers circumvent this problem and only ask retrospectively, people often no longer know whether they were consciously aware of their activities.

However, you can observe unconscious brain activities with imaging methods - for example, something stirs in the brain when test subjects see stimuli below the conscious perception threshold, i.e. images are only presented to them for fractions of a second, for example. Activities in the brain can also be measured when someone is faced with a decision but has not yet made a conscious decision. As early as the 1980s, the American physiologist Benjamin Libet recorded unconscious brain activities in advance of a conscious decision, the so-called readiness potential. In 2008 my research group continued Libet's experiments and found that up to seven seconds before a conscious decision you can predict how someone will make a decision based on brain activity. One can interpret these brain activities as an unconscious preparation process for the decision.

An important question, however, is whether this preparation, once set in motion, inevitably leads to a certain action - whether with the first impulse the decision takes its course inexorably, like a falling row of dominoes. Our new study carried out at the Berlin Charité should answer this question. To do this, we tracked the readiness potential that arises before a movement is carried out in real time using the EEG and observed whether test subjects can still stop a preparation for movement that has been started. Indeed, it was possible - they could choose to stop the move. This suggests that people can consciously take back decisions made unconsciously even very shortly before their practical implementation. The decision-making process begins, but humans can stop it at will. However, unconscious processes are always involved in this conscious decision. So we cannot get out of the entanglement of the unconscious processes.

Recorded by Natalie Steinmann