Neurolaw November I – Introduction into Neurolaws

This is the second part of our Neurolaw reading series. You can find the first part HERE.

Humans are first and foremost animals – even though we tend to deny that. Animals with morality, guided by the norms of their group and their feelings. We follow the guiding principles of our society which, for example, prohibit us from harming others. And the result is that this society punishes violations as a mechanism for functioning cohabitation. But how free is a human being? Is he always to blame if he violates these principles? And, more importantly, can I recognize a criminal solely by his brain?

Science has been searching for a long time for answers to these questions and of special importance is the quest for a locus of morality in our brain. Similarly, there is a search for the changes in our brain structure that lead to altered behaviors. Throughout all these studies the question always arises as to whether we really decide what we can do or whether we do not have the opportunity to decide. Numerous studies have shown that criminal offenders show some changes in the brain and its activity compared to the general populace. However, in research we are not yet ready to say whether we should judge these offenders differently in court. On the other hand, there is always the question whether there are people with the same changes in the brain, who lead a life without violating the laws. Beyond all this it is important to always keep in mind and never forget that there is a different, highly-dynamic brain in every human being. This is straightforward evidence in the subject of plasticity: our brain is not a static construct, but it is always changing. Connections are strengthened when we are repeatedly exposed to a subject area, but data are also deleted. Every human being is, and thinks, differently – and this of course has its merits. Hence, it also follows that small changes in the brain can not always serve as an excuse for any offense but one should think about the possibility thoroughly.

Today, there are quite a few insights that can be applied directly in court. And it is also not likely that the neurosciences will fundamentally change the legal sciences. However, with advanced research it is conceivable that scientific knowledge could at least enter into court proceedings in the future.

Phineas Cage, a story of a changed personality

I would like to highlight in the following some aspects in which changes in the brain structure could be associated with changes in personality. One of the most famous cases is that of Phineas Gage. In 1848 Phineas Gage survived an accident in which an iron rod was pushed through his skull, severely damaging his brain’s prefrontal cortex. Physically, he recovered quickly, but he suffered severe changes in his personality. His friends often said that he was no longer the “real Gage”. This is one of the cases that dislodged a discussion about the functional specialization of certain brain regions.[1]

A word on human brain design: The prefrontal cortex, as the front part of the frontal lobe, lies in front of the motor brain regions. It receives information from almost all areas of the cerebrum and other brain areas and also sends information to most areas. However, its function is particularly interesting since according to recent research, this area of the brain has special significance for the psychological behavior of a person, his higher social performance as well as the respect of the basic values ​​of his society. This is the reason why lesions in this area also lead to personality changes. Patients are caught up in the fact that their behavior is discouraged and they no longer observe social norms, behave in a tactless manner, and are often indifferent to them. To put it succinctly: they flatten emotionally. There are many other causes for changes in the prefrontal cortex. These include, for example, a tumor that presses on the brain tissue.

Pedophile inclination caused by a brain tumor – then disappeared

Another known case is that of a 40-year-old father who one day developed a pedophile inclination toward his own children. Once in prison he reported having a severe headache, which was in fact due to a tumor pressing on his right frontal lobe. He underwent surgery to have the tumor removed and his pedophile inclinations completely disappeared.  What is your first thought about this case? Was it the father’s fault? And what happens if he decided not to have his tumor removed surgically? Do you see this man as a slave of his own physical changes? These are just some of the questions currently argued between both, neuro scientists and legal scholars.[2]

Enzym MAO and Brunner Syndrome

Another example is the risk gene “MAO”. This stands for the enzyme “Monoaminooxidase A”, which degrades the neurotransmitter serotonin in the brain. This gene variant leads to the “Brunner syndrome” people inflicted with which have a stronger tendency towards criminal and/ or aggressive behavior. However, not all carriers of this gene are conspicuous. In order for this characteristic to occur, the gene carrier must be traumatically stressed.[3]

All this information shakes our view of ourselves. We are always thinking about whether our actions are self-determined. Does a sick brain force me to violate the guiding principles of my own society? And does a healthy brain protect me from becoming an offender? The reigning opinion is that a healthy brain enables choice – and so there must be synonymous criminal offenses without structural brain changes. And this is probably very safe. That the condition of our brain can affect our behavior has been known for a long time. Processes in the brain can decide whether one is happy today or sad. What would happen if criminals were blamed for wrongdoing in court? Most likely, you could not participate in social life anyway. Individuals inflicted with brain damage would be treated in psychiatric hospitals in order not to harm anyone. However, this treatment might cost these people much more time of their lives than an imprisonment would do.  And from this point onwards, this person is considered to be led by his own brain.

This article is intended to give a brief introduction into the field that arises from the overlapping of law and neurosciences. It is certain that much will be carried out in the coming years and certainly a lot more information will be discovered as well. And it can be shown by the examples given above that there are indications in the brain regarding the potential for criminal behavior. But for now there seems to be no real benefit from these insights. There are still no patterns with the help of which one could decide whether particular brain anatomy is responsible for certain behavior, but the research so far is also – admittedly – not yet advanced enough. And even if there were further findings suggesting that certain changes in the brain structure are causally related to consequent violations of the law, one still has to ask whether all people with these changes automatically deserve a waiver for their deeds. It is imaginable that one day it will be self-evident that neurological assessments of a criminal will be the basis for the ruling of a judge. How large the influence will be, time will tell. The scientist Gazzangia once said: “guilty, but ill”. The idea that we are solely guided by our brains surely can be terrifying. It seems certain, however, that the future of Neurolaw research will be very exciting, and for that reason, we should be curious.


Maureen is a fifth-semester med-student at Goethe University in Frankfurt/Main, Germany. She is Vice Chair and Founding Member of the German Neuroscience Olympiad Frankfurt (Non-Profit Organization, the “DNO”). Through her work for the DNO she organizes regional contests and education for talented pupils in the field of neuroscience. This engagement gives her the opportunity to extend her knowledge in neuroscience – a field that always fascinated her.

Her manifold volunteering and great academic successes led to several honors and scholarships. She is an active runner and currently perfecting her half-marathon performance.

Also see:

Brain Waves Module 4: Neuroscience and the law, The Royal Society, December 2011, ISBN: 978-0-85403-932-6

Tracking the Unconscious Generation of Free Decisions Using Ultra-High Filed fMRI, June 2011, Volume 6, (

Amygdala, affect and cognition: evidence from 10 patients with Urbach-Wiethke disease ( )

Einsatz bildgebender Verfahren im Strafprozess, (

Neuroanatomie, Struktur und Form, Martin Trepel, 6. Auflage, Urban&Fischer, 2015

How predictable are „spontaneuous decisions“ and „hidden intentions“? Comparing classfication results based on previous responses with multivaraite pattern analysis of fMRI BOLD signals (