How many times did you move your eyes to read this sentence? 

When Nature Neuroscience decided their front cover would feature eye movement research, they approached Bristol neuroscientist Iain Gilchrist to provide an appropriate image.  Iain, in the department of Experimental Psychology, uses  eye movement recording  as a central technique in his research into  visual perception.  By overlaying a photograph of a desert landscape with the route made by the eyes as they tracked up sand dunes and along the horizon, the cover that was produced gives a graphic and striking demonstration of how we move our eyes when surveying a scene.

Iain and colleagues are able to record such movements with the aid of an EyeLink®II eye tracker.  This equipment consists of a headband mounted with miniature cameras.  These cameras then record the point of gaze at a collection rate of 500 Hz as the eyes move back and forth relative to the position of the head.

With the eyetracker it becomes possible to find out how many times we do move our eyes when reading a sentence (probably between 7 - 10 times for the sentence above). 

Answering such questions and, more generally, questions on the role of eye movements in collecting and the subsequent processing of visual information, allows Iain to draw conclusions about brain function and the mechanisms involved in cognition. 

Ludwig CJ, Gilchrist ID, Goal-driven modulation of oculomotor capture.
Percept Psychophys. 2003 Nov;65(8):1243-51.

To see the cover of Nature Neuroscience go to: http://www.nature.com/neuro/covers/v7n1/

Find out more about Bristol Neuroscience at: http://www.bris.ac.uk/neuroscience/