The time course of predictability effects in reading: Evidence from a survival analysis of fixation durations

To investigate the time course of predictability effects in reading, the present study examined distributions of first-fixation durations on target words in a low predictability versus a high predictability prior context. In a replication of Staub (2011), ex-Gaussian fitting demonstrated that the low predictability distribution was significantly shifted to the right of the high predictability distribution in the absence of any contextual differences in the degree of skew. Extending this finding, the present study used a survival analysis technique to demonstrate a significant influence of predictability on fixation duration as early as 140 ms from the start of fixation, which is similar to prior results obtained with the word frequency variable. These results provide convergent evidence that lexical variables have a fast acting influence on fixation durations during reading. Implications for models of eye-movement control are discussed.