Disappearing text reveals what controls eye movements in reading
When reading, people make a series of eye movements separated by fixations. It is during the eye fixations (typically 200-300 ms) that new information is acquired.
To investigate the factors that determine when the eyes move during reading, Dr Sarah White and colleagues used a novel paradigm in which text literally disappeared in front of a reader's eyes. Each time the eyes fixated on a word, it disappeared after 60 ms. Participants were asked to read sentences containing high- or low-frequency target words under normal reading conditions or disappearing-text conditions.
Cognitive-control theory postulates that it is the mental activities required to process a given word that drive the eyes through the text, and hence predicts that readers should remain fixated on a low-frequency word longer than on a high-frequency word, even when the word has disappeared. By contrast, visual/oculomotor-control models predict no difference between how long readers look at high- and low-frequency words under disappearing-text conditions. That is, because the visual information needed for reading is gone after 60 ms, the eyes should move after approximately the same amount of time regardless of whether readers fixate low- or high-frequency target words.
The results obtained by Dr White and colleagues support the prediction of cognitive-control theory. Even though the fixated word had disappeared after 60 ms, readers continued fixating for a longer period on locations where low-frequency words had been.
This finding demonstrates that it is the cognitive processes needed to understand a word that determine when the eyes move in reading, rather than visual/oculomotor-control processes. Although the uptake of visual information is important and necessary for reading to occur, it is the mental operations on that information that propel the eyes through the text.
Publications
- Rayner K, Liversedge SP and White SJ. (2006). Eye movements when reading disappearing text: The importance of the word to the right of fixation. Vision Research, 46, 310-323.
- Rayner K, Liversedge SP, White SJ and Vergilino-Perez D. (2003). Reading disappearing text: Cognitive control of eye movements. Psychological Science, 14, 385-388.
