For most people, the inner workings of the brain and the resulting behaviour work seamlessly, and we behave in “socially acceptable” ways. But, what happens when the brain is “faulty?” Take for instance the famous case of Phineas Gage, who had a tragic accident at work, where a railroad blasting rod pierced through his skull into his brain. Mr. Gage survived this accident, however, his once well-behaved personality was altered to a more chaotic one. He began gambling, and became short-tempered, impulsive, and violent. Mr. Gage had suffered damage to the area of the brain known as the orbitofrontal cortex, implicated in emotional regulation, decision making, and impulse control.
Phinease Gage suffered brain trauma from a rod that pierced through his skull || (Source: Flickr // Protocol Snow)
If, for instance, Mr. Gage had killed someone in a barfight, without premeditation; by today’s legal standards, would Mr. Gage be found guilty (of 2nd degree murder or manslaughter) or would he instead be found not criminally responsible on account of mental disorder (NCRMD)? Is he responsible for his aberrant, perhaps incontrollable, behaviour ensuing from a traumatic brain injury? Or to the crux of the issue, are humans responsible for their behaviour, if it is nothing more than the result of brain function? A biological view of behaviour suggests that regardless of whether someone has a rod in their brain (tumour or other forms of severe brain trauma), all of their actions are controlled by their brain’s function.
The Guilty Mind
The above example is an introduction to the deterministic view of human behaviour as dictated by our brain (mal)functioning. Mr. Gage’s actions were determined by a brain that “misfired” as a result of physical trauma, leaving very little room for the concept of free will and voluntary action. This poses a fundamental challenge to the concept of criminal justice that relies on a crucial principle: that only the morally guilty should be punished. Guilt is determined by a defendant’s level of culpability, or in legal terms, their mens rea, which comes from the Latin phrase actus reus non facit reum nisi mens sit rea, translated to “the act is not culpable unless the mind is guilty.” The basic tenets of criminal justice inform our conception of mens rea: guilt is determined by one’s capacity to distinguish right from wrong and subsequent choice to act in the wrong. There is an assumption of free will and voluntary action. What happens to mens rea if the neuroscientific understanding of brain and behaviour removes free will from the agent? This question has lead to such defences as sane automatism, which can lead to full acquittal because it removes voluntary action from the individual.
The Not-so-Guilty Mind
To understand the case below (R v Stone), let me first explain the concept of automatism. There are two types of automatism defences: the first is sane automatism, where involuntary behaviour does not result from a mental disorder and is a complete defence, giving rise to full acquittal. For instance, sane automatism could be used as a defence if a defendant had murdered someone during a sleepwalking episode. Indeed, the Supreme Court of Canada, in R v. Parks, upheld the trial decision of allowing sleepwalking to be used as a sane automatism defence. This brings back the notion of mens rea: that only voluntary actions may lead to legal culpability. Generally, the factors required for a sane automatism defence must be extrinsic and are as follows: (1) there must exist an involuntary action arising from external source (or reflex action); (2) the action must be completely involuntary; and (3) the automatism must not be self-induced (that is why excessive alcohol/drug consumption is not a viable defence of automatism).
What happens to mens rea if the neuroscientific understanding of brain and behaviour removes free will from the agent?
The second type is insane automatism, where the actions of the accused are held to be the result of a mental disorder and triggers s.16 of the Canadian Criminal Code leading to a defendant being found NCRMD, again reflecting that the defendant could not appreciate the nature and quality of their act. Recall the earlier example of Mr. Gage killing a patron during a bar brawl; which of the two automatism defences could be argued most effectively? Would Mr. Gage’s brain injury justify the use of insane automatism because it would be considered as resulting from an internal cause? Or would the murder be acquitted under a sane automatism defence because Mr. Gage’s brain injury had an external causal factor [a rod] and was exacerbated by alcohol consumption? The predicament raised by the automatism defences, and the fine line between what is considered sane or insane by the courts, identifies a disconnect between fictional legal dichotomies and the neuroscientific reality that our brain controls our behaviour in all situations. This renders the concept of voluntariness moot to the eyes of science.
(mis)Communication of Science in the Courtroom
In recent years, there has been a sharp increase in the use of expert witnesses in courts which exemplifies a shift in the legal paradigm toward “hard facts,” stemming from science and its rigorous methodology. Among these experts are psychologist, psychiatrists, neuroscientists, and other specialists whose mandate is to inform the triers-of-fact in making more scientifically-informed judgements. When neuroscience meets the legal discipline, it is coined neurolaw.
In 1999, the Supreme Court of Canada was confronted with the challenging case of R v. Stone where Mr. Stone was appealing the guilty verdict of manslaughter for the killing of his wife via 47 stabbings. The trial judge had instructed the jury to consider insane automatism as a defence, but this failed, and he received a seven-year imprisonment sentence for manslaughter. The appeal, asking for Mr. Stone to be found NCRMD, was dismissed by the majority of the Supreme Court justices. However, three of the justices dissented, stating that the assessment of the appellant’s mental status at the time of the crime was not fully presented to the jurors. Specifically, the forensic psychiatrist brought in as an expert witness testified that the appellant was in a dissociative state, considered an unconscious state, when killing his wife. Furthermore, this was not attributed to a mental disorder, but rather a reaction to severe stress allegedly inflicted on him by his wife. The trial judge, and the concurring appeal judges, stated that although the accused had “periods” of unconsciousness during the murder, the expert witness did not assess the lack of voluntariness required for the defence of automatism. Interestingly, the jurors found that the appellant did not commit the crime voluntarily, thus resulting in a guilty verdict of manslaughter. The problem here is that the trial judge had only informed the jury of insane automatism, which requires the presence of a mental disorder (which the appellant did not have). Had the judge informed the jury about sane automatism, the verdict may have been a full acquittal.
A dissociative state can cause impaired consciousness || (Source: Flickr // Vlad Gilcescu)
The lack of proper instruction to the jurors in R v. Stone brings forward a very important issue arising from the increased use of science in court. Namely, a need for comprehensive scientific literacy on the part of the jurists. In this case, the SCC dismissed the appeal partly on the grounds that the steps required for the insane automatism defence were not satisfied, stating: “As I have explained above, automatism is more properly defined as impaired consciousness, rather than unconsciousness. Furthermore, lack of voluntariness, rather than consciousness, is the key legal element of automatism. Accordingly, the trial judge should have concerned himself with assessing whether there was evidence that the appellant experienced a state of impaired consciousness in which he had no voluntary control over his actions rather than whether there was evidence that the appellant was unconscious throughout the commission of the crime.”
Although eloquent in its rhetoric, this reasoning does not reflect the state of the scientific evidence. The judge rests the dismissal of the appeal on a false dichotomy between unconsciousness and impaired consciousness, wherein he posits that the former does not fall in the latter. If the question of whether unconsciousness fell in the realm of impairments of consciousness was put to a neuroscientist, several questions about what was meant about impairment and in what context would follow. Rooted in the context of R v. Stone the unequivocal answer would be a strong affirmative of: “Indeed, Mr. Stone was impaired of consciousness.” The next question for the neuroscientist would be: “If the appellant suffered from impairment of consciousness resulting from a dissociative state, could his actions be considered of his own volition?” The logical answer would be in the negative. The issue appears to boil down to one of mismatched communication. Where jurors, attorneys, and judges would benefit from increased scientific literacy to clarify the issues put before them and assess the true worth of the expert testimony, and where neuroscientist (and experts in general) could use a crash course in legal standards and a disambiguation of legal jargon.
Loïc Welch is an Online Editor of the McGill Journal of Law and Health and a first-year B.C.L./LL.B. student at McGill University’s Faculty of Law. Loïc holds a M.Sc. in Forensic Psychology from Maastricht University (Netherlands), was a research assistant at the Douglas Mental University Institute in Montreal, and interned at the Professional Clinical and Forensic Services, a part of the Institute of Violence, Abuse, and Trauma in San Diego, California.