Parafoveal-on-Foveal Effects in Reading and Word Recognition

Abstract

In this Chapter, I want to raise some questions concerning the ‘attention-switching’ model of eye movement control in reading first proposed by Morrison (1984). A basic assumption of this model is that after a criterion level of processing has been reached on a given word n (for example, lexical access), attention will shift discretely to the next word, n+1, while the eyes remain fixating n. At the same time as this attentional shift takes place, an eye movement is programmed towards word n+1. Thus, for a period of time, a reader may be fixating word n, preparing to make a saccade, and processing word n+1. If the processing of word n+1 is completed before the saccade takes place, a further switch of attention (to word n+2) may occur and a second saccade will be programmed, in parallel with the first. The way the oculomotor system deals with simultaneous programming of more than one saccade depends on their relative timing (Becker and Jurgens 1979). If the trigger commands are widely separated in time, both saccades may be executed, but the duration of the fixation following the first may be drastically reduced. If the delay is short, only the second saccade will be initiated. Between these limits, a ‘compromise’ saccade may be launched, to an intermediate target position.