Psychopathic violent offenders have abnormalities in the parts of the brain related to learning from punishment, according to an MRI study led by Sheilagh Hodgins and Nigel Blackwood. “One in five violent offenders is a psychopath. They have higher rates of recidivism and don’t benefit from rehabilitation programmes. Our research reveals why this is and can hopefully improve childhood interventions to prevent violence and behavioural therapies to reduce recidivism,” explained Professor Hodgins of the University of Montreal and Institut universitaire en santé mentale de Montréal. “Psychopathic offenders are different from regular criminals in many ways. Regular criminals are hyper-responsive to threat, quick-tempered and aggressive, while psychopaths have a very low response to threats, are cold, and their aggressively is premeditated,” added Dr. Nigel Blackwood, who is affiliated with King’s College London. “Evidence is now accumulating to show that both types of offenders present abnormal, but distinctive, brain development from a young age.”
In order to develop programs that prevent offending and rehabilitation programs that reduce re-offending, it is essential to identify the neural mechanisms underlying psychopath’s persistent violent behaviour. “We have been using Magnetic Resonance Imaging to study brain structure and function in a sample of violent offenders in England, one group with psychopathy and one without, and a sample of healthy non-offenders. We have found structural abnormalities in both gray matter and specific white matter fiber tracts among the violent offenders with psychopathy,” Hodgins explained. Grey matter is mostly involved with processing information and cognition, while white matter coordinates the flow of information between different parts of the brain.
12 violent offenders with antisocial personality disorder and psychopathy, 20 violent offenders with antisocial personality disorder but not psychopathy, and 18 healthy non-offenders participated in the study. The offenders had been convicted of murder, rape, attempted murder and grevious bodily harm, and were recruited from Britain’s probation service. “We observed reductions in gray matter volumes bilaterally in the anterior rostral prefrontal cortex and temporal poles relative to the other offenders and to the non-offenders,” Hodgins said. These brain regions are involved in empathy, the processing of pro-social emotions such as guilt and embarrassment, and moral reasoning. “Abnormalities were also found in white matter fiber tracts in the dorsal cingulum, linking the posterior cingulate cortex to the medial prefrontal cortex that were specifically associated with the lack of empathy that is typical of psychopathy,” Blackwood added. These same regions are involved in learning from rewards and punishment.
In order to engage in appropriate behaviour, it is essential to learn from punishment, both real and imagined. “Most individuals do not walk in front of buses as they can imagine the horrible consequences if the bus hits them. Offenders do not walk in front of buses either, suggesting that they also learn from punishment, nor do they show less sensitivity to punishment than others,” Hodgins said. “In childhood, both psychopathic and non-psychopathic offenders alike are repeatedly punished by parents and teachers for breaking rules and for assaulting others, and from adolescence onwards, they are frequently incarcerated. Yet they persist in engaging in violent behaviour towards others. Thus, punishment does not appear to modify their behaviour.”
While inside the brain scanner, the violent offenders and non-offenders completed a task that assessed their ability to adjust their behaviour when the consequences of their responses changed from positive to negative. The task was an image matching game – sometimes points were awarded for correctly pairing images, sometimes they weren’t. “When these violent offenders completed neuropsychological tasks, they failed to learn from punishment cues, to change their behaviour in the face of changing contingencies, and made poorer quality decisions despite longer periods of deliberation,” Blackwood explained.
The researchers also examined activity across the brain during the completion of the task. “We found that the violent offenders with psychopathy, as compared to both the violent offenders without psychopathy and the non-offenders, displayed abnormal responding to punishment within the posterior cingulate and insula when a previously rewarded response was punished. Our previous research had shown abnormalities in the white matter tract connecting these two regions. In contrast, the violent offenders without psychopathy showed brain functioning similar to that of the non-offenders,” Blackwood explained. “These results suggest the violent offenders with psychopathy are characterized by a distinctive organization of the brain network that is used to learn from punishment and from rewards.”
Deciding on what to do involves generating a list of possible actions, weighing the negative and positive consequences of each, and hopefully choosing the behaviour most likely to lead to a positive outcome. “Offenders with psychopathy may only consider the possible positive consequences and fail to take account of the likely negative consequences. Consequently, their behavior often leads to punishment rather than reward as they had expected,” Hodgins said. “Punishment signals the necessity to change behaviour. Clearly, in certain situations, offenders have difficulty learning from punishment to change their behaviour.”
Conduct problems and the antecedents of psychopathy emerge early in life when learning-based interventions have the potential to alter brain structure and functioning. “Programs that teach parents optimal parenting skills lead to significant reductions in conduct problems among their children, except among those who are callous and insensitive to others. As our studies and those of others show, the abnormalities of brain structure and function associated with persistent violent behavior are subtle and complex,” Blackwood explained. “The results of our studies are providing insights into the neural mechanisms characterizing adult violent offenders that may be used, along with other findings, in designing programs to reduce recidivism. Our results also provide hypotheses about the abnormal development of violent offenders to be tested in studies of children.”
This information is critical to the development of programs to prevent violent criminality. “Since most violent crimes are committed by men who display conduct problems from a young age, learning-based interventions that target the specific brain mechanisms underlying this behaviour pattern and thereby change the behaviour would significantly reduce violent crime,” Hodgins said.
In people with dyslexia, less gray matter in the brain has been linked to reading disabilities, but now new evidence suggests this is a consequence of poorer reading experiences and not the root cause of the disorder.
It has been assumed that the difference in the amount of gray matter might, in part, explain why dyslexic children have difficulties correctly and fluently mapping the sounds in words to their written counterparts during reading. But this assumption of causality has now been turned on its head.
The findings from anatomical brain studies conducted at Georgetown University Medical Center (GUMC) in the Center for the Study of Learning led by neuroscientist Guinevere Eden, DPhil, were published online today in The Journal of Neuroscience.
The study compared a group of dyslexic children with two different control groups: an age-matched group included in most previous studies, and a group of younger children who were matched at the same reading level as the children with dyslexia.
“This kind of approach allows us to control for both age as well as reading experience,” explains Eden, a professor of pediatrics at GUMC. “If the differences in brain anatomy in dyslexia were seen in comparison with both control groups, it would have suggested that reduced gray matter reflects an underlying cause of the reading deficit. But that’s not what we observed.”
The dyslexic groups showed less gray matter compared with a control group matched by age, consistent with previous findings. However, the result was not replicated when a control group matched by reading level was used as the comparison group with the dyslexics.
“This suggests that the anatomical differences reported in left hemisphere language processing regions appear to be a consequence of reading experience as opposed to a cause of dyslexia,” says Anthony Krafnick, PhD, lead author of the publication. “These results have an impact on how we interpret the previous anatomical literature on dyslexia and it suggests the use of anatomical MRI would not be a suitable way to identify children with dyslexia,” he says.
The work also helps to determine the fine line between experience-induced changes in the brain and differences that are the cause of cognitive impairment. For example, it is known from studies in illiterate people who attain reading skills as adults that this type of learning induces growth of brain matter. Similar learning-induced changes in typical readers may result in discrepancies between them and their dyslexic peers, who have not enjoyed the same reading experiences and thus have not undergone similar changes in brain structure.
Enlightened Neurons: Can Meditation Beef Up Brain Regions?
After Sara Lazar suffered a running injury in the 1990s, she decided to take up yoga and meditation. She remembers rolling her eyes whenever the teacher touted the supposed benefits of yoga: stress relief, a reduction in symptoms associated with depression and insomnia, and a happier and higher quality of life. After a few weeks though, Lazar’s outlook changed. “I started noticing that I was calmer and I was better able to handle difficult situations… and I was feeling more compassionate and open-hearted towards other people,” she said in a 2011 talk at TEDx Cambridge. Lazar, who was a Ph. D student in molecular science at the time of her injury, decided to change her career focus to study the neuroscience of meditation.
Now Lazar is one of a growing number of researchers who are using Magnetic Resonance Imaging—a medical technique that uses a magnetic field and radio waves to peer inside the body—to see how meditation may mold the brain.
In a paper published today in Proceedings of the National Academy of Sciences (PNAS), researchers for the first time comprehensively describe existing abnormalities in brain function and structure of long-term marijuana users with multiple magnetic resonance imaging (MRI) techniques. Findings show chronic marijuana users have smaller brain volume in the orbitofrontal cortex (OFC), a part of the brain commonly associated with addiction, but also increased brain connectivity.
“We have seen a steady increase in the incidence of marijuana use since 2007,“said Dr. Francesca Filbey, Associate Professor in the School of Behavioral and Brain Sciences at the University of Texas at Dallas and Director of the Cognitive Neuroscience Research in Addictive Disorders at the Center for BrainHealth. “However, research on its long-term effects remains scarce despite the changes in legislation surrounding marijuana and the continuing conversation surrounding this relevant public health topic.”
The research team studied 48 adult marijuana users and 62 gender- and age-matched non-users, accounting for potential biases such as gender, age and ethnicity. The authors also controlled for tobacco and alcohol use. On average, the marijuana users who participated in the study consumed the drug three times per day. Cognitive tests show that chronic marijuana users had lower IQ compared to age-and gender-matched controls but the differences do not seem to be related to the brain abnormalities as no direct correlation can be drawn between IQ deficits and OFC volume decrease.
“What’s unique about this work is that it combines three different MRI techniques to evaluate different brain characteristics,” said Dr. Sina Aslan, founder and president of Advance MRI, LLC and adjunct assistant professor at The University of Texas at Dallas. “The results suggest increases in connectivity, both structural and functional that may be compensating for gray matter losses. Eventually, however, the structural connectivity or ‘wiring’ of the brain starts degrading with prolonged marijuana use.”
Tests reveal that earlier onset of regular marijuana use induces greater structural and functional connectivity. Greatest increases in connectivity appear as an individual begins using marijuana. Findings show severity of use is directly correlated to greater connectivity.
Although increased structural wiring declines after six to eight years of continued chronic use, marijuana users continue to display more intense connectivity than healthy non-users, which may explain why chronic, long-term users “seem to be doing just fine” despite smaller OFC brain volumes, Filbey explained.
“To date, existing studies on the long-term effects of marijuana on brain structures have been largely inconclusive due to limitations in methodologies,” said Dr. Filbey. “While our study does not conclusively address whether any or all of the brain changes are a direct consequence of marijuana use, these effects do suggest that these changes are related to age of onset and duration of use.”
The study offers a preliminary indication that gray matter in the OFC may be more vulnerable than white matter to the effects of delta-9-tetrahydrocannabinol (THC), the main psychoactive ingredient in the cannabis plant. According to the authors, the study provides evidence that chronic marijuana use initiates a complex process that allows neurons to adapt and compensate for smaller gray matter volume, but further studies are needed to determine whether these changes revert back to normal with discontinued marijuana use, whether similar effects are present in occasional marijuana users versus chronic users and whether these effects are indeed a direct result of marijuana use or a predisposing factor.
Video gaming causes increases in the brain regions responsible for spatial orientation, memory formation and strategic planning as well as fine motor skills. This has been shown in a new study conducted at the Max Planck Institute for Human Development and Charité University Medicine St. Hedwig-Krankenhaus. The positive effects of video gaming may also prove relevant in therapeutic interventions targeting psychiatric disorders.
In order to investigate how video games affect the brain, scientists in Berlin have asked adults to play the video game “Super Mario 64” over a period of two months for 30 minutes a day. A control group did not play video games. Brain volume was quantified using magnetic resonance imaging (MRI). In comparison to the control group the video gaming group showed increases of grey matter, in which the cell bodies of the nerve cells of the brain are situated. These plasticity effects were observed in the right hippocampus, right prefrontal cortex and the cerebellum. These brain regions are involved in functions such as spatial navigation, memory formation, strategic planning and fine motor skills of the hands. Most interestingly, these changes were more pronounced the more desire the participants reported to play the video game.
“While previous studies have shown differences in brain structure of video gamers, the present study can demonstrate the direct causal link between video gaming and a volumetric brain increase. This proves that specific brain regions can be trained by means of video games”, says study leader Simone Kühn, senior scientist at the Center for Lifespan Psychology at the Max Planck Institute for Human Development. Therefore Simone Kühn and her colleagues assume that video games could be therapeutically useful for patients with mental disorders in which brain regions are altered or reduced in size, e.g. schizophrenia, post-traumatic stress disorder or neurodegenerative diseases such as Alzheimer’s dementia.
“Many patients will accept video games more readily than other medical interventions”, adds the psychiatrist Jürgen Gallinat, co-author of the study at Charité University Medicine St. Hedwig-Krankenhaus. Further studies to investigate the effects of video gaming in patients with mental health issues are planned. A study on the effects of video gaming in the treatment of post-traumatic stress disorder is currently ongoing.
Regular cannabis use shrinks the brain but increases the complexity of its wiring, a study has found.
To some extent the loss of brain volume is balanced by larger numbers of connections between neurons, scientists discovered.
But they warn that those who take the drug for too long are likely to suffer damaging effects.
The brain scan study of cannabis users is one of the first to investigate the drug’s long-term neurological impact in living people.
Dr Sina Aslan, from the University of Texas at Dallas, US, who co-led the research, said: “What’s unique about this work is that it combines three different MRI (magnetic resonance imaging) techniques to evaluate different brain characteristics.
“The results suggest increases in connectivity, both structural and functional that may be compensating for grey matter losses. Eventually, however, the structural connectivity or ‘wiring’ of the brain starts degrading with prolonged marijuana use.”
The study showed that after six to eight years of continually taking cannabis the increases in structural wiring declined. Photograph: Mykel Nicolaou/Rex Features
New research has revealed that exposure to common family problems during childhood and early adolescence affects brain development, which could lead to mental health issues in later life.
The study led by Dr Nicholas Walsh, lecturer in developmental psychology at the University of East Anglia, used brain imaging technology to scan teenagers aged 17-19. It found that those who experienced mild to moderate family difficulties between birth and 11 years of age had developed a smaller cerebellum, an area of the brain associated with skill learning, stress regulation and sensory-motor control. The researchers also suggest that a smaller cerebellum may be a risk indicator of psychiatric disease later in life, as it is consistently found to be smaller in virtually all psychiatric illnesses.
Previous studies have focused on the effects of severe neglect, abuse and maltreatment in childhood on brain development. However the aim of this research was to determine the impact, in currently healthy teenagers, of exposure to more common but relatively chronic forms of ‘family-focused’ problems. These could include significant arguments or tension between parents, lack of affection or communication between family members, physical or emotional abuse, and events which had a practical impact on daily family life and might have resulted in health, housing or school problems.
Dr Walsh, from UEA’s School of Psychology, said: “These findings are important because exposure to adversities in childhood and adolescence is the biggest risk factor for later psychiatric disease. Also, psychiatric illnesses are a huge public health problem and the biggest cause of disability in the world.
“We show that exposure in childhood and early adolescence to even mild to moderate family difficulties, not just severe forms of abuse, neglect and maltreatment, may affect the developing adolescent brain. We also argue that a smaller cerebellum may be an indicator of mental health issues later on. Reducing exposure to adverse social environments during early life may enhance typical brain development and reduce subsequent mental health risks in adult life.”
The study, which was conducted with the University of Cambridge and the Medical Research Council Cognition and Brain Sciences Unit, Cambridge, is published in the journal NeuroImage: Clinical.
The 58 teenagers who took part in the brain scanning were drawn from a larger study of 1200 young people, whose parents were asked to recall any negative life events their children had experienced between birth and 11 years of age. The interviews took place when the children were aged 14 and of the 58, 27 were classified as having been exposed to childhood adversities. At ages 14 and 17 the teenagers themselves also reported any negative events and difficulties they, their family or closest friends had experienced during the previous 12 months.
A “significant and unexpected” finding was that the participants who reported stressful experiences when aged 14 were subsequently found to have increased volume in more regions of the brain when they were scanned aged 17-19. Dr Walsh said this could mean that mild stress occurring later in development may ‘inoculate’ teenagers, enabling them to cope better with exposure to difficulties in later life, and that it is the severity and timing of the experiences that may be important.
“This study helps us understand the mechanisms in the brain by which exposure to problems in early-life leads to later psychiatric issues,” said Dr Walsh. “It not only advances our understanding of how the general psychosocial environment affects brain development, but also suggests links between specific regions of the brain and individual psychosocial factors. We know that psychiatric risk factors do not occur in isolation but rather cluster together, and using a new technique we show how the general clustering of adversities affects brain development.”
The researchers also found at that those who had experienced family problems were more likely to have had a diagnosed psychiatric illness, have a parent with a mental health disorder and have negative perceptions of their how their family functioned.