The 'center of gravity' of words: evidence for an effect of the word-initial letters.

When the eye saccades to eccentric word targets, it tends to land in a position which can be described as the center of gravity of the configuration. By manipulating the relative intensity of the word-initial and -ending letters, it was shown that the 'global effect' of luminance distribution within words is strongly attenuated when the word-initial letters are informative and orthographically irregular. Results show that the orthographic structure of the word-initial letters exerts an influence on the saccadic computation that may cancel the luminance distribution effect.