Eye Movements Reveal the On-Line Computation of Lexical Probabilities during Reading

• Published in: Psychological science Vol. 14; no. 6; pp. 648 - 652
• Main Authors: McDonald, Scott A., Shillcock, Richard C.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA Blackwell Publishing 01-11-2003; SAGE Publications; SAGE PUBLICATIONS, INC
• Subjects: Bayes Theorem; Cognition; Cognition & reasoning; Cognitive psychology; Eye Movements; Fixation, Ocular; Humans; Linguistics; Nouns; Perception; Predictability; Probabilities; Psychology; Reading; Research Reports; Verbs; Visual fixation; Visual perception; Vocabulary; Word frequency analysis; Words
• ISSN: 0956-7976; 1467-9280
• DOI: 10.1046/j.0956-7976.2003.psci_1480.x

Skilled readers are able to derive meaning from a stream of visual input with remarkable efficiency. In this article, we present the first evidence that statistical information latent in the linguistic environment can contribute to an account of reading behavior. In two eyetracking studies, we demonstrate that the transitional probabilities between words have a measurable influence on fixation durations, and using a simple Bayesian statistical model, we show that lexical probabilities derived by combining transitional probability with the prior probability of a word's occurrence provide the most parsimonious account of the eye movement data. We suggest that the brain is able to draw upon statistical information in order to rapidly estimate the lexical probabilities of upcoming words: a computationally inexpensive mechanism that may underlie proficient reading.