Institute for Research in Child Development

What is an eye-tracker?

• Eye-tracking equipment is now very easy to use and the eye-tracker itself looks just like a normal computer monitor.
• It offers a fast and detailed means of assessing a whole range of early abilities in babies.
• All the baby has to do is sit on their caregivers lap and watch the screen and the eye-tracker immediately works out exactly what the infant is looking at.
• After the stimuli are presented the tracker can play back the infant’s pattern of looking so this can be shown to the parents.
• TALBY study will involve the presentation of stimuli that are attractive to babies and that will make sense to the parents, including dynamic videos of faces and objects and a variety of speech sounds.  

Why study baby eye movements?

Infants already in the first months of life are able to control their eye movements, in other words - their visual attention. Infancy researchers study the patterns of looking to assess infants' preferences for different objects, abilities to distinguish between things (e.g. 'at what age babies distinguish cats from dogs?') and their abilities to learn new information.

How does it work?

• It uses infra-red light (just like in your TV remote control) that reflects off the eye's cornea and retina.
• Then, a computer works out the angle of looking using the two reflections and plots the exact point that infants are looking at in a video.
• We can follow frame-by-frame baby's eye movements recorded together with the video she/he watched. The bigger the red dot - the longer the baby looked at one spot.

See a video example below:

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© 2008