When you can't recognise people you know
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Imagine a world where you couldn't recognise your husband, your parents or even yourself. This is the reality for sufferers of prosopagnosia, commonly known as face blindness.
Macquarie University PhD student Laura Schmalzl together with supervisors Professor Max Coltheart and Dr Romina Palermo, hope that by looking at which perceptual and cognitive processes are impaired in prosopagnosia they will provide important information for the diagnosis of face recognition impairments and the implementation of management strategies.
Prosopagnosia refers to a selective difficulty in recognising familiar people by their faces. In everyday life, those with the condition are forced to rely on cues such as voice, clothing, hair or gait to identify familiar people. Severely affected people can't even recognise themselves from facial features alone.
To date, the majority of documented cases of prosopagnosia are of people who have acquired the condition following some type of brain injury.
Congenital prosopagnosia
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PhD student Laura Schmalzl |
The main focus of Schmalzl's research at present is on a more rare type of face blindness, congenital prosopagnosia. There have only been nine well documented case studies of this form over the past 26 years.
"These people never develop normal face recognition skills during their lives in the context of normal perceptual skills and intellectual functioning," explains Schmalzl. "Small children who have this difficulty may often be misdiagnosed with behavioural difficulties. It impacts on their social development and they may not interact with other people as other children do."
For the past year Schmalzl and her supervisors have been researching four generations of one family who are affected by congenital prosopagnosia. They are the first team in Australia doing a family study on congenital prosopagnosia as well as looking at the genetic aspects of the condition.
The study commenced with two small children who presented to the Children's Hospital at Westmead with suspected high functioning autism. On assessment these children appeared absolutely normal in intellectual functioning. Eventually they were diagnosed with a selective difficulty in recognising faces.
"We assessed them by showing photographs of very immediate people such as their parents, brothers or sisters and removed key cues such as hair, and they had significant difficulties," Schmalzl says. "They couldn't even recognise themselves but their performance improved when you added hair."
Apart from looking at exactly which perceptual and cognitive processes break down in congenital prosopagnosia, Schmalzl is also looking at whether the condition is hereditary or genetic. "We have initiated a collaboration with geneticists at Westmead Hospital with the aim to conduct molecular DNA analysis," says Schmalzl. "Establishing a potential link between a specific genetic makeup and a high-level cognitive function such as face processing would be a dramatic breakthrough in the way we understand human cognition."
Schmalzl, who is two years into her PhD, will travel to the Prosopagnosia Research Centre in London later this year to collaborate with fellow researchers.
For further information contact Schmalzl lschmalz@maccs.mq.edu.au, her supervisors Professor Max Coltheart max.coltheart@mq.edu.au and Dr Romina Palermo romina.palermo@mq.edu.au, or visit the Macquarie Centre for Cognitive Science website www.maccs.mq.edu.au/research/projects/faceresearch/index.htm