Brain Machine Interfaces – where do free will end and technology begin? by Jana Maresch


BCI technologies have been advancing at a fast rate in recent years, allowing paralyzed patients to move and locked-in patients to communicate again. This technology is based on reading out electric signals from the user’s scalp, amplifying and filtering them, and then translating them into movement or words. Thus, for many patients BCIs don’t only mean recovery of function, they mean much more: BCIs can restore these patients’ free will. However, as with any major advancement in technology or science, with BCIs there are two sides of the coin. The first side being the recovery of the user’s free will by enabling him to move again; the second one dealing with the problem of a not yet optimized appliance that could take part of the acquired freedom away again.


Free will is a hard to define concept, though, especially when looking at human-machine interactions. So let’s start with the basic concept of free will. In the Merriam Webster on line dictionary “free will” is described as ‘voluntary choice or decision’ and ‘freedom of humans to make choices that are not determined by prior causes or by divine intervention’. Okay, so we have a definition. But what does it mean exactly? This question closely relates to theories of physical determinism, and its compatibility with free will. These discussions have been confined to philosophy until about half a century ago, when this topic was addressed by neuroscience for the first time. In 1985, the pioneer in the field of human consciousness, Benjamin Libet, found a so-called ‘readiness potential’ culminating in subjects’ prefrontal cortex long before subjects became aware of their intention to take action. This means that our actions may be triggered by unconscious neural activity and that the awareness of those actions only occurs when we think we are willing to act. We can still change our minds, of course; our conscious will can either bring an action to completion or it can block it. This veto or intentional inhibition is again implemented by the prefrontal cortex, and preceded by neural activity as Patrick Haggard more recently showed in his 2009 research. Haggard is a cognitive neuroscientist whose field of interest seems to be a continuation of Libet’s research as he is interested in voluntary action, motor cognition and somatosensation.


So what does all of this have to do with BCIs? For one, invasive BCIs can be implanted in the posterior parietal cortex (PPC), an area responsible for the mapping and planning of movement. As a BCI is designed to pick up neural signals, it may detect preliminary signals (such as Benjamin Libet described), and actions may be performed before the user actually becomes aware of them.

Another possibility of BCI application uses artificial intelligence (AI) as a mediator. AI can refer to a wide scope of machines; essentially, however, the term is used when a machine mimics ‘cognitive’ functions such as learning and problem solving. In this case, the AI recognizes sequences of movements and learns to anticipate them. A similar problem as the one described above occurs when the user wants to change the sequence but the AI responds with the anticipated movement.

In both cases, the free will of the user may be compromised. He is no longer the master of his deeds, but the subject to the BCI’s interpretation of the signals it receives. You might wonder whether this indeed is a real problem or just a philosophical consideration on free will. Well, it is both. As ancient as the discussion about free will is, it is also always connected to guilt assignment which is a crucial question in the case of BCI. What if one of the unwanted actions leads to harming another? Who is to blame? The user, even though it was not his intention to perform this movement, the BCI, or the AI?


Although there is no definite answer, it seems obvious that we need to take a step back and

(re-)define free will in the modern setting of BCIs and AIs. The challenge surely is the integration and translation of a philosophical question into modern technology and science. As mentioned before, attempts herein have been made. However, these lack both an overall view of the challenges BCIs form for social and ethical life and practical guidelines for flaws of the system, such as unintended actions.

So what is the take-home message? I think it is awareness. Being and becoming aware of what advancement in technology and science mean for us, particularly in a practical sense. Scientists and engineering companies have merged their abilities and knowledge in order to create these amazing appliances. What we need now is awareness of and guidelines for the intricacies and implications of BCIs in order to use them to their full potential.


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