Prof. Dr. Christoph Herrmann heads the Experimental Psychology Lab at the Department of Psychology. He researches brain processes involved in attention, memory and perception, as well as the modification of these processes through non-invasive brain stimulation.


Prof. Dr. Christoph Herrmann

Department of Psychology

Free will under attack

Free will under attack

We see ourselves as aoutonomous beings who can consciously decide to do or not to do something. However, neuroscience experiments raise doubts about this perception. Does free will exist at all?

When do humans act of their own free will? This can be assessed according to three criteria, says Oldenburg psychologist Prof. Dr Christoph Herrmann: "A person should be able to act differently in the same situation; the action should be voluntary, that is in accordance with his or her own convictions; and thirdly, it should come from within oneself, that is it should not be controlled by someone else". That humans can act freely according to these criteria has been in question since the 1980s. Back then, the US psychologist Benjamin Libet observed that a certain brain activity – the so-called readiness potential – occurs before test persons consciously decide to perform a movement. He postulated that seemingly voluntary decisions are actually controlled by unconscious processes in the brain. The subjective feeling of being able to decide freely is therefore an illusion, Libet therefore concluded.

Researchers are still debating how to interpret the experiment. Herrmann, who heads the Experimental Psychology Lab at the university, found out in a study that the readiness potential already occurs before test persons even know which movement they should perform. According to him and his team, the signal merely represents a general expectation of having to do something right away. "We like to think that we have repelled Libet's attack on free will with this," he sums up. Other research results worldwide also indicate that Libet's conclusions were probably too far-reaching. Experiments conducted by researchers in Freiburg in 2016 even showed that test persons can successfully resist the impulse to act represented by the readiness potential. The probands were thus able to consciously change their brain signal.

Yet the issue of free will remains tricky. Few deny that unconscious processes influence some of our actions. Herrmann also assumes that our decisions are determined by habits, previous experiences and early childhood imprinting – that we are not necessarily free to make a choice completely independent of any influence. For him, however, this does not rule out volitional action. "According to the philosopher Michael Pauen, freedom of will is possible even in a determined world, as long as you understand freedom as self-determination," Herrmann explains. According to the Oldenburg neuroscientist, what matters is that persons decide for themselves and that their actions are not controlled by coercion or chance. "In my view, this is a satisfactory solution to the dilemma".

(Changed: 26 Apr 2022)