Understanding Children’s Behavioural Problems

31 March 2006

Most children who bully other kids, torture animals, and steal or vandalise property, are diagnosed with conduct disorder. Displaying extreme antisocial behaviour, at times accompanied by an absence of emotion, empathy, guilt or remorse, these children typically experience lifelong difficulties in functioning within society and have high rates of incarceration, depression and suicide.Yet the question of what causes the disorder and how to treat it continues to trouble scientists.

Spearheading new research, a 24-year-old Sydney University doctoral student is helping map out the causal pathways to such behaviour. Donna Palmer, from the psychology department and the Brain Dynamics Centre at the Westmead Millennium Institute, is examining the ways in which emotional and social information is processed within the brains of children with conduct disorder. She has been awarded funding from the Australian Rotary Health Research Fund – up to $78,000 over three years – to undertake the study.

“The causes of extreme behaviours range from environmental situations, such as abusive or neglectful families, to strong genetic or biological influences where there are no obvious adverse familial or social factors. This diversity presents a significant challenge for treatment interventions,” explained Ms Palmer.

She is researching the extent to which some children with conduct disorder – specifically those displaying “callous-unemotional” traits – are unable to recognise emotions in others. “In many of these cases, normal neural processing of emotional information is disrupted. The problem is biological,” she said.

In her study, children are shown facial displays of fear, happiness, anger, sadness, disgust and neutral emotional expressions. Their responses are recorded at conscious and unconscious detection levels through body arousal – sweat rate, heart rate – and EEGs or electroencephalography.
“By placing an electrode-covered cap on the child’s head and measuring the electrical brain activity, we can monitor how the waveforms of the brain change due to stimuli,” explained Ms Palmer.

This neural testing allows her to tease out the biological differences in the brain responses of different groups of children to various emotional stimuli. By analysing a child’s brain waves in the first half second after exposure to a stimulus – for example, an angry face – Ms Palmer can ascertain the exact stage of processing that is disturbed in these children.

“My hypothesis is that those children who display a difference of processing in the first 200 milliseconds have a problem neurally. While other children may display enhanced brain wave responses when they see an angry face, children with “callous-unemotional” traits may display much smaller waves. These responses are so quick, they are likely to be caused by genetics rather than environment,” she said.

By examining what is happening in the brain, Ms Palmer said that scientists will be able to determine the regions of the brain which are different in these children. “This will lead to new treatments that directly target the core problem,” she said.

Ms Palmer’s research is one of five University studies to benefit from the $1.97 million in medical research grants offered nationally by the Australian Rotary Health Research Fund in 2006. Other projects include a study on the mental and physical health of women caring for Vietnam veteran husbands, the role of iron in breast cancer, the evaluation of a home visiting program for new mothers, and the effects of malaria on the lungs.

Kate Rossmanith
This story first appeared in Uni News 31 March 2006