Neurocriminology : A Review on Aggression and Criminal Behaviors Using Brain Imaging

Criminology has been understood within a sociological framework until the emergence of neurocriminology, which describes, understands and predicts criminal behaviors from a neurobiological point of view. Not only using biological factors including genes and hormones to understand criminal behaviors, but also using neuroimaging techniques, the field of neurocriminology aims to delve into both structural and functional differences in the brain of individuals with aggression, antisocial personalities, and even the criminals. Various studies have been conducted based on this idea, however, there still are limitations for the knowledge from these studies to be used in the court. In this review article, we provide an overview of the various research in neurocriminology, and provide insight into the future direction and implication of the field.

Aggression and Neurotransmitters

Aggression and aggressive behaviors, often explained as harmful social interaction with the intention of hurting or inflicting damage upon another, have been considered as an adaptive mechanism from the evolutionary psychological point of view. However, various studies on aggression and aggressive behaviors have been done with psychopathological approach as the extreme aggressive behaviors may harm themselves and others at the same time. Recently, researchers have attempted to explain aggression in terms of neurobiological substrates rather than based on traditional psychopathological and/or behavioral concept. In this regard, there have been findings of differences in neurotransmitters and their receptors, and genetic polymorphisms. In this review article, we provide a brief overview of the literature about seven most frequently reported neurotransmitters including neurohormones (serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, nitric oxide, oxytocin and vasopressin) and an associated enzyme (monoamine oxidase A), which are known to be related with aggression and aggressive behaviors.

Molecular Neuroimaging in Posttraumatic Stress Disorder

Over the past decade, an increasing number of neuroimaging studies have provided insight into the neurobiological mechanisms of posttraumatic stress disorder (PSTD). In particular, molecular neuroimaging techniques have been employed in examining metabolic and neurochemical processes in PTSD. This article reviews molecular neuroimaging studies in PTSD and focuses on findings using three imaging modalities including positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance spectroscopy (MRS). Although there were some inconsistences in the findings, patients with PTSD showed altered cerebral metabolism and perfusion, receptor bindings, and metabolite profiles in the limbic regions, medial prefrontal cortex, and temporal cortex. Studies that have investigated brain correlates of treatment response are also reviewed. Lastly, the limitations of the molecular neuroimaging studies and potential future research directions are discussed.