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Updated: Aug 19, 2026

Assessing Dyslexia at Six Year of Age
Published on: May 1, 2020
Dyslexia and the centre-of-gravity effect
1Mental Health and Neural Systems Research Unit, Department of Psychology, Lancaster University, Lancaster LA1 4YF, UK. t.crawford@lancaster.ac.uk
Abstract:
When human observers are presented with a double target display, a saccadic eye movement is triggered to an intermediate position close to the 'centre-of-gravity' of the configuration. This study examined the saccadic eye movements of dyslexic and normal readers in response to displays of single and double targets. Eye movement analyses revealed no differences in the spatial position of saccadic eye movements of dyslexic and normal readers in response to single targets presented at 5 degrees or 10 degrees. However, when presented with two targets simultaneously at 5 degrees AND 10 degrees, in contrast to normal readers who generated saccades to an intermediate position between the two targets (towards the 'centre-of gravity'), dyslexics generated saccades that landed close to the near target eccentricity. These findings suggest that dyslexia is associated with a deficit in the processing of global spatial information for the control of saccadic eye movements.
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