Over the last thirty years, psycholinguists have converged on a model of
language comprehension in which perceptual input (e.g., sounds)
incrementally activates higher-level representations (e.g., possible
messages), which in turn constrain the interpretation of subsequent
percepts. Such a system should allow for prediction: the use of
top-down information to anticipate the meaning and form of upcoming
words. While form based prediction is sometimes present under
laboratory conditions, there is no consensus on whether prediction is