Diagnosing dyslexia with visual clues

Pioneering research at ANU is bringing the effective diagnosis and treatment of dyslexia a step closer.

Visual scientists Dr Ted Maddess and Dr Andrew James are working with psychological scientist Dr Kristen Pammer to develop a new test to help understand — and possibly treat — dyslexia.

The researchers are seeking volunteers who suffer from visual discomfort — a condition that is often misdiagnosed as dyslexia. Symptoms include text seeming to be ‘floating’ or ‘carved into the page’, the background ‘overtaking’ the text, and the text ‘swimming’ or ‘shimmering’. Sufferers may find that it is helpful to have the lights dim when reading, and use coloured overlays, glasses or paper.

“A lot of people confuse visual discomfort with dyslexia, because you have difficulty reading,” said Dr Pammer.

“One of the reasons to start with visual discomfort is we know it is a disorder which is visual, whereas the visual component of dyslexia is only part of the problem.”

The brain of a visual discomfort sufferer is thought to react differently to ‘crowding’. Crowding is the situation where a letter can easily be read when it appears alone, but becomes harder to distinguish when surrounded by other ‘distracter’ letters.

The test works by measuring the brain’s responses to visual stimuli.

Following a control stimulus, the subject is exposed to further stimuli which mimic overcrowding. Electrodes measure the subject’s brain responses under each set of conditions.

The first step for the researchers is to develop a definitive test for visual discomfort, which will prevent misdiagnosis of the condition. The team then hopes to move on to dyslexia: developing tests, gathering data and eventually finding new treatments.

“If it is possible to better understand the problem we can develop therapies,” said Dr Maddess.

“The deeper issue is that if we understand more we can cure or even prevent dyslexia.”

To volunteer for the study, contact Dr Pammer.

E: kristen.pammer@anu.edu.au