The frontal cortex and the criminal justice system

Abstract

In recent decades, the general trend in the criminal justice system in the USA has been to narrow the range of insanity defences available, with an increasing dependence solely on the M'Naghten rule. This states that innocence by reason of insanity requires that the perpetrator could not understand the nature of their criminal act, or did not know that the act was wrong, by reason of a mental illness. In this essay, I question the appropriateness of this, in light of contemporary neuroscience. Specifically, I focus on the role of the prefrontal cortex (PFC) in cognition, emotional regulation, control of impulsive behaviour and moral reasoning. I review the consequences of PFC damage on these endpoints, the capacity for factors such as alcohol and stress to transiently impair PFC function, and the remarkably late development of the PFC (in which full myelination may not occur until early adulthood). I also consider how individual variation in PFC function and anatomy, within the normative range, covaries with some of these endpoints. This literature is reviewed because of its relevance to issues of criminal insanity; specifically, damage can produce an individual capable of differentiating right from wrong but who, nonetheless, is organically incapable of appropriately regulating their behaviour.

The Science of Self, Mind and Body

“…In addition, a similar comparison of the inner versus physical self with the functions of the prefrontal cortex (PFC) and other brain structures reported by Sapolsky (2004), and Miller and Cohen (2001). Table 1 shows a remarkable good correlation or agreement between characteristic aspects of the inner versus physical self Table 1.…”

“…Comparison of characteristic aspects of performance of the inner self (Chung, 2009) and the prefrontal cortex of the human brain (Sapolsky, 2004;Miller & Cohen, 2001). …”

“…If the PFC is normal and fails to yield to control by the inner self and chooses anti-social wrong behaviors, then the inner self would be responsible for the wrong or illegal behavior or act. If someone with epilepsy strikes another person in the course of a seizure, "it is not him; it is his disease" (Sapolsky, 2004). The above cases seem to be analogous to the driving a car as above described: the inner self (self of an individual) is the driver and responsible in driving, and the steering wheel and engine with the car body that are the physical self/body (the PFC and other brain structures and the body) are not responsible.…”

“…The authors described extensively about scientific aspects of the will power in self-control in our lives and relevant informative scientific researches. Sapolsky (2004), a neurobiologist at Stanford University reported on the basis of findings in contemporary neuroscience that the role of the prefrontal cortex (PFC) of the human brain is cognitive control, emotion regulation, control of impulsive behavior and moral reasoning. Miller and Cohen (2001) at Stanford University proposed an integrative theory of prefrontal cortex function of cognitive control, goals and rules.…”

“…Psychologists, psychiatrists and neuroscientists have been recently doing researches with help of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) to study the brain structures and functions, particularly the prefrontal cortex of the brain (Sapolsky, 2004;Miller & Cohen, 2001;Greene, 2001;Banks et al, 2007;Rilling & Insel, 1999;Braun et al, 1998;Herman et al, 2005;Bauer et al, 1998;Gusnard, 2009). The prefrontal cortex is its largest, in both absolute and relative terms, in the human among anthropoid primates (Rilling & Insel, 1999;Sapolsky, 2004).…”