DR. GABOR MATÉ

Wednesday, August 2, 2000

Last week the journal Science reported that in people prone to violence, the portion of the brain responsible for emotional self-regulation appears to be short-circuited. These scientific findings concerning how the brain may malfunction raise questions about our understanding of human behaviour. And they pose a challenge to our fundamental assumptions about education, law and some current child-rearing practices.

Researchers have identified the orbitofrontal cortex as the cerebral area where dysfunction is likely to be located in individuals subject to hostile outbursts and aggression. The orbitofrontal cortex is part of the prefrontal cortex, the area of grey matter most involved in social intelligence, impulse control, and attention. So-named because of its proximity to the eye socket, or orbit, the orbitofrontal cortex is more developed in the right hemisphere, the side of the brain that dominates our emotional functioning. This crucial portion of grey matter appears to have the responsibility of evaluating and regulating emotional impulses, such as fear and rage, generated in the lower brain centres.

Whenever people exhibit impulsive outbursts of emotion accompanied by failures of behavioural self-control, we're likely witnessing short-circuiting of the wiring of the orbitofrontal cortex. Such short-circuiting occurs not only during episodes of overt violence, but also during everyday failures of self-regulation, be it episodes of road rage, or in children throwing temper tantrums on the playground, or in parents "losing it" and screaming at their children.

We tend to view the cortex as the "thinking" part of the brain, and therefore as the initiator of human activity. In reality, one of its most important functions is inhibition.

"The cortex's job is to prevent the inappropriate response, rather than to produce the appropriate one," psychologist and neuroscientist Joseph LeDoux has written. Impulsive outbursts of aggression do not necessarily result from a conscious decision by an individual to do something violent. Instead, there may be a failure on the part of the orbitofrontal cortex to dampen a hostile urge originating in structures deep down in the brain that function well below the level of consciousness. By the time the person becomes aware of the impulse to act, he may have already committed the deed.

As we come to understand the neurophysiological substrate of human behaviours, we should be less inclined to judge and condemn our fellow human beings, and more interested in inquiry into how precisely the brain develops the capacity for self-regulation.

What can interfere with the wiring of the orbitofrontal cortex? Injury to the brain may be at fault, as was the case in some of the subjects reviewed in the Science article. Genetic predisposing factors may also contribute in some cases. However, the commonest source of disruption to the circuitry of self-regulation is neither physical trauma nor heredity, but the absence of the conditions required for proper development.

There is now a large body of evidence suggesting that the infant's emotional interactions with its primary caregivers provide the major influence on the physiological and biochemical development of the brain regions responsible for emotional and behavioural self-control. When infants and young children lack parenting, which is emotionally nurturing and consistently available, given in a non-stressed atmosphere, research suggests that problems of self-regulation often result. The greater the deprivation, the less optimally the orbitofrontal cortex is likely to develop and function, and the greater the predictable difficulties in self-regulation.

Children's future brain functioning depends on fully attentive and emotionally consistent parenting during the early years. Were we to fully grasp that fact, current social policies would surely change to support parents in that essential task -- rather than, as is now the case, forcing many families to place economic goals above the needs of child-rearing.

Evidence is that the self-regulating parts of the brain can develop throughout the life cycle, depending on the appropriate input from the environment. Were schoolteachers and administrators to understand the relationship between brain development and behaviour, they would be less punitive in their approach to children with self-regulation problems, more likely to ask themselves what empathic approaches could help such children develop the brain circuits and psychological capacities needed for self-control.

And while the legal system could not excuse violent behaviours based on what PET (positron emission tomography) scans may reveal about the brain, the law could show much more understanding toward human beings whose early lives did not allow for the optimal development of brain structures needed for self-regulation.

There's little doubt that a significant percentage of prison inhabitants have various disorders of self-regulation. Little doubt, too, that prison conditions are virtually designed to exacerbate such mental and physiological brain dysfunctions, rather than to help people gain mastery over them.

Gabor Maté, a Vancouver physician, is the author of  Scattered Minds: A New Look at the Origins and Healing of Attention Deficit Disorder.