BOX 4.1 TECHNIQUES USED TO EXAMINE THE STRUCTURAL INTEGRITY OF THE BRAIN
Computerized axial tomography (CAT). CAT scans are produced using a series of x-rays taken along the axis of the body. The x-rays pass unevenly through tissues of different densities, allowing for distinctions between fluid, bone and brain tissue to be made. A computer then assembles these slices into a sequence of cross-sectional images.
Magnetic resonance imaging (MRI). MRI scans are created by using powerful magnetic fields to orient all of the hydrogen atoms (primarily found in water molecules) in the brain in the same direction. A radio frequency electromagnetic field is introduced, which produces a signal that is detected by the MRI scanner’s receiver. These signals are then assembled into high-resolution images that can distinguish the grey from the white matter of the brain. MRI scans do not use radiation and they produce more detailed pictures than do CAT scans, but they also take much longer to obtain and are much more expensive. That said, both types of imaging produce images of brain structures that can then be measured and studied.
Diffusion tensor imaging (DTI). This is a relatively new technique, allowing images to be taken of the structural integrity of the white matter tracts connecting various parts of the brain.
BOX 4.2 TECHNIQUES USED TO EXAMINE THE FUNCTIONAL ASPECTS OF DIFFERENT AREAS OF THE BRAIN
Functional magnetic resonance imaging (fMRI). This measures changes in blood oxygen in regions of interest in the brain before and after cognitive tasks are undertaken. These blood oxygen level dependent (BOLD) signals are used as a proxy for how active a region of the brain is. By comparing groups of interest with matched controls, the patterns of activation, or inactivation, in their brains can be studied to learn how the functioning of various brain regions relates to the condition in question.
Positron emission tomography (PET). This technique relies on injecting subjects with a radioactively labelled substance, such as glucose. Images of their brains can then be obtained, showing areas of higher radioactive signal due to glucose metabolism, which indicates level of neural activity.
Single photon emission computed tomography (SPECT). This form of imaging also involves the injection of a radioactive tracer. The camera detects the amount of radiation coming from different parts of the brain. These differences are due to differences in regional cerebral blood flow (rCBF) and reflect different levels of activity in various parts of the brain.
Electroencephalogram (EEG) measurement. In an EEG, the subject has electrodes placed in specific points over the scalp. These electrodes detect the brain’s electrical impulses, which are then recorded and analysed by a computer. The frequency and amplitude of the resultant signals can then be interpreted. Increasing frequency is associated with increasing arousal, and lower frequency is associated with lower arousal.
Event-related potential (ERP). This is a measure of the magnitude of change of brain activity after the presentation of specific stimuli. The change, or deflection, may be positive or negative in direction, and occurs within milliseconds of the onset of the stimulus. Typically, an ERP is measured several times, and the average of all the trials is taken. P300 is a positive waveform that typically occurs approximately 300 milliseconds after the presentation of a stimulus. It reflects processes involved in stimulus evaluation or categorisation (i.e. it is related to the engagement of attention).
4.3.1 Evidence Suggesting Problems in the Structural Integrity of the Brains of Offenders
As regards studies that have looked at structural problems in offenders’ brains, Raine, Lencz, Bihrle, LaCasse and Colletti (2000) studied 21 individuals with antisocial personality disorder (ASPD), and compared them to a matched group of substance users, and non-offending controls. They found an 11% reduction in the grey matter of the OPFC of the ASPD group compared to the other two matched groups. Other researchers have found that individuals with ASPD have smaller temporal lobes (Dolan, Deakin, Roberts, & Anderson, 2002; Laakso et al., 2002) compared to normal controls, as well as reductions in their dorsolateral, medial frontal, and the OPFC (Laakso et al., 2002). Laakso and colleagues (Laakso et al., 2000; Laakso et al., 2001) also found in a group of violent offenders (with alcoholism and ASPD), that the smaller the posterior hippocampus (an area which is associated with fear conditioning), the higher the antisocial score.
Antisocial personality disorder (ASPD) is described in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (American Psychiatric Association, 2013) as “pervasive pattern of disregard for and the violation of the rights of others” (p. 659), and can include a disregard for social norms, deceitfulness, impulsivity, irritability/aggressiveness, reckless disregard for the safety of others, consistent irresponsibility and lack of remorse for what they have done.
Huebner et al. (2008) found smaller grey matter volumes in the OPFC and temporal lobes of children with conduct disorder (CD), compared to normal controls. Sterzer, Stadler, Poustka, and Kleinschmidt (2007) found reduced grey matter volumes in the amygdala and the insular of adolescents with CD compared to normal controls. Kruesi, Casanova, Mannheim, and Johnson-Bilder (2004), report that diminished right temporal lobe volume (which includes the amygdala) is associated with CD; and reduced temporal lobe, but not prefrontal volumes, in incarcerated psychopaths.
Conduct disorder (CD) is defined as a repetitive, and persistent, pattern of behaviour in childhood in which the basic rights of others or societal conventions are flouted, and is often seen as precursor of later antisocial behaviours. Many individuals with CD show little empathy and concern for others, and may frequently misperceive the intentions of others as being more hostile and threatening than is actually the case.
Psychopaths cannot be easily identified by any distinctive clinical symptoms, but they have personality characteristics that can be broadly described as: criminally minded; glib/superficially charming; manipulative; lack of remorse or guilt/conscience; pathological lying; lack of emotional depth; irresponsibility and impulsiveness; callous parasitic lifestyle; poor behavioural controls; promiscuous sexual behaviour and a history of childhood (antisocial) problems. Psychopaths also show emotional empathy deficits. Obviously this mix of personality traits and behaviours makes it highly likely that such individuals will commit crimes.
PHOTO 4.1 It could be anyone . . . the lack of easily recognisable symptoms mean that it is very difficult to tell who is a psychopath.
Source: © Christopher Robbins/Getty Images
4.3.2 Evidence Suggesting Functional Problems in the Brain of Offenders
As regards scanning studies examining functional problems in offenders, Birbaumer et al. (2005) found that psychopaths show no significant activity in limbic-prefrontal circuitry (i.e. the amygdala, OPFC, insula and ACC) employing an fMRI, during tasks involved in verbal and autonomic conditioning. The lack of recognition of fear in psychopaths, due to a measurable lack of amygdala function, would suggest that this would make it easier to offend. Raine et al. (1994) in a PET study, found that a sample of murderers demonstrated reduced glucose metabolism in the anterior medial prefrontal, OPFC and superior frontal cortices compared to a normal comparison group, after a continuous performance task. A follow-up study with a larger sample using a similar methodology found the same pattern of reduced glucose metabolism in the anterior frontal cortices, and in the amygdalas and hippocampi as well (Raine, Buchsbaum, & LaCasse, 1997).
Sterzer, Stadler, Krebs, Kleinschmidt and Poustka (2005) employed an fMRI technique to examine patterns of brain activation in individuals with conduct disordered (CD) adolescent males, and 14 matched controls, as neutral pictures and pictures with a strong negative affective valence were shown to them. It was found that when the CD youths viewed the distressing pictures they had significantly reduced activity to their left amygdalae compared to the controls. Another group using a similar methodology studied 24 children and adolescents with callous-unemotional traits and either oppositional defiant disorder or CD, 12 with attenti
on deficit hyperactivity disorder, and 12 comparison controls. All looked at photographs of neutral, angry or fearful faces. Compared to the other two groups, the group with callous-unemotional traits demonstrated significantly reduced amygdala activation on viewing the fearful (but not the angry or neutral) faces (Marsh et al., 2008). Further, on a functional connectivity analysis, the callous-unemotional children showed reduced connectivity between the ventromedial prefrontal cortex and the amygdala. The degree of reduction in this connectivity was negatively correlated with the score on a scale that measured the degree of callous-unemotional traits. Similar findings have been described in adult populations (Muller et al., 2003; Kiehl et al., 2004).
Slower EEG activity in children and adolescents has been found to be associated with later criminal behaviour (Mednick, Volavka, Gabrielli, & Itil, 1981; Petersen, Matousek, Mednick, Volvaka, Pollock, 1982), while Raine, Venables, and Williams (1990) demonstrated that, compared to their peers with higher arousal, 15-year old boys with lower arousal as measured by resting EEG were more likely to become criminals at age 24. Children with externalising and antisocial behaviours have been noted to demonstrate abnormal patterns of EEG asymmetry in their frontal lobes (Ishikawa & Raine, 2002; Santesso, Reker, Schmidt, & Segalowitz, 2006). It has been noted that dominant EEG frequencies increase with age (Dustman, Shearer, & Emmerson, 1999). The EEG abnormalities noted with respect to criminal behaviour have been hypothesised to be due to cortical immaturity (Volavka, 1987). It has been suggested that abnormal frontal EEG asymmetry might belie language and analytic reasoning deficits, thus impairing emotion regulation (Santesso et al., 2006).
A meta-analysis of studies of ERP in antisocial populations found that, in general, antisocial individuals have smaller P300 amplitudes and longer latencies (Gao & Raine, 2009). Early onset of drug abuse and criminal behaviour have also been shown to be related to smaller P300 amplitudes (Iacono & McGue, 2006) Other studies have demonstrated that greater negative amplitude at 100 milliseconds (N100) (elicited by any unpredictable stimulus in the absence of task demands) and faster P300 latency at age 15 predict criminal behaviour at age 24 (Raine et al., 1990).
Neuropsychological tests provide another method for testing the functional level of various brain areas. One of the most consistent findings in the neuropsychological aspects of criminality is that antisocial populations have lower verbal IQs compared to non-antisocial groups (Brennan, Hall, Bor, Najman, & Williams, 2003; Déry, Toupin, Pauzé, Mercier, & Fortin, 1999; Teichner & Golden, 2000). Researchers have found that verbal deficits on testing at age 13 predict delinquency at age 18 (Moffitt, Lynam, & Silva, 1994). A number of authors have also found evidence that such neuropsychological deficits show interactive effects when they are present in children with social risk factors as well.
Executive functioning is another neuropsychological function of interest in criminology (Moffitt, 1990; Moffitt, 1993). A meta-analysis of 39 studies incorporating data from 4,589 individuals examined the relationship between executive dysfunction and antisocial behaviour (Morgan & Lilienfeld, 2000). These authors found significant effect sizes (d = 0.86 for juvenile delinquency and d = 0.46 for conduct disorder) for executive dysfunction. Other neuropsychological tests have focused on how antisocial populations respond to affectively charged stimuli. Loney, Frick, Clements, Ellis, and Kerlin (2003) found that juveniles with callous-unemotional traits showed slower reaction times after being presented with emotionally negative words, while those with impulsive traits showed faster reaction times to such stimuli. Adult psychopaths have been found to have deficits in passive-avoidance learning tasks (Newman & Kosson, 1986) and adolescent psychopaths have been shown to demonstrate hyper- responsivity to rewards (Scerbo et al., 1990). Taken together, these data suggest that psychopathic individuals will be less sensitive to punishment and more sensitive to the possibility of rewards as a consequence of their behaviour. Also, given the executive function literature, they may be less able to plan, act in a rationally self-interested fashion, control their impulses and respond flexibly to the various problems encountered in everyday life. In the next section of the chapter we will examine the risk factors that can effect the structure and functions of the brain and the potential relationship to offending.
4.4 RISK FACTORS FOR OFFENDING
Box 4.3 outlines the factors that can create disturbances in the neurobiological processes of the brain, sometimes in combination with genetic factors. We will now examine these in more detail.
4.4.1 Genetic Factors and Offending
One way to investigate whether there is a genetic component to a problem is to compare the frequency with which there is co-occurrence in siblings, particularly monozygotic (MZ) and dizygotic (DZ) twins.
BOX 4.3 FACTORS THAT CAN LEAD TO PROBLEMATIC BRAIN DEVELOPMENT
Genetic factors
Abnormalities in foetal development
Other prenatal factors: (e.g., smoking in pregnancy, maternal alcohol consumption during pregnancy leading to foetal alcohol syndrome)
Perinatal risk factors (birth complications, maternal rejection)
Post-natal risk factors (adverse childhood experiences, poor nutrition, head injury)
Parent-child relationships (attachment experiences)
Substance abuse in adolescence and adulthood
Monozygotic (MZ) (identical) twins arise from a single ovum and have exactly the same genetic material. Dizygotic (DZ) (fraternal) twins arise from two separate ova, and like any siblings share 50% of the same genes
Blonigen, Carlson, Krueger, and Patrick (2003) reporting on 353 adult twins of self-reported psychopathic personality traits found substantial evidence of genetic contributions to variance in overall self-reported levels of psychopathy using the Psychopathic Personality Inventory (PPI; Lilienfeld & Andrews, 1996) in MZ (n = 165; correlation effect size r = .46, p < .05) compared to DZ twins (n = 106; r = −0.26, non-significant result); and in all of the subscales of the PPI (including Machievellianism; coldheartedness and impulsiveness). Larsson, Andershed, and Lichtenstein (2006) investigated the genetic basis for psychopathy using the ACE (“A” = genes; “C” = shared family environment; “E” = environmental risk factors unique to the individual, such as head injury). They found that “A” (genes) accounted for 63% of the variance, “C” accounted for 0%, and “E” (the unique environment) accounted for 37% of the variance. In contrast, Miles and Carey (1997) examining aggression in a meta-analytic study, found that genes (“A”) and shared environment (“C”) were equally important in explaining aggressive behaviour, while Rhee and Waldman (2002) in a meta-analytic study of over 100 behavioural genetic studies, found that 40–50% of the variance of antisocial behaviour was due to genetic inheritance (“A”), 15–20% to shared environmental influences (“C”) and 30% unique environmental influences (“E”).
Adoption studies are another mechanism for studying the genetic versus the environmental contributions to antisocial behaviour. In such studies, the characteristics of a child’s biological and adoptive parents are considered relative to the child’s own behaviour. Gabrielli and Mednick (1984), in a large sample of adoptees in Denmark, found strong evidence for a genetic propensity for criminal behaviour, while a study of 862 Swedish male adoptees found that genetic influences were the most significant contributor to later criminal behaviour (Cloninger, Sigvardsson, Bohman, & von Knorring, 1982). In this study the researchers also found that if a person had both a biological parent and an adoptive parent who were criminals, the person’s likelihood of criminal behaviour was greater than the sum of the individual risks. In other words, there was a multiplicative effect of having a biological predisposition to crime and then being raised in a criminogenic environment.
Another example of gene/environment interaction is work that has found a connection between a version of the monoamine oxidase A (MAO-A) gene (3R) (commonly known as the “warrior gene”) and several types of antisocial behaviour.
The warrior gene comprises particul
ar variations in the X chromosome gene that produces monoamine oxidase A (MAO-A), an enzyme that affects the neurotransmitters dopamine, norepinephrine and serotonin
Although overall MAO-A has been found to have no overall effect on antisocial behaviour, low MAO-A activity in combination with abuse experienced during childhood results in an increased risk of aggressive behaviour as an adult (Frazzetto et al., 2007), while Caspi et al. (2002), in a large study of gene-environment interaction, identified people with high or low MAO-A activity and also whether or not the individual had been abused as a child. They found evidence of a strong interaction between low MAO-A activity and childhood maltreatment in terms of the likelihood of developing conduct disorder. Developmental risk factors such as maternal smoking during pregnancy, poor material living standards and dropping out of school, as well as low IQ, were found to be associated with violent behaviour in men with the low-activity alleles (which are overwhelmingly the 3R allele) (Fergusson, Boden, Horwood, Miller, & Kennedy, 2012).
Finally, adoption studies are another mechanism for studying genetic and environmental interactions in antisocial behaviour (e.g., Rhee & Waldman, 2002). In a study of 862 Swedish male adoptees by Cloninger et al. (1982), it was found that if a person had both a biological parent and an adoptive parent who were criminals, the person’s likelihood of criminal behaviour was greater than the sum of the individual risks. In other words, there was a multiplicative effect of having a biological predisposition to crime and then being raised in a criminogenic environment.
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