Little is known about how information to the left of fixation impacts reading and how it may help to integrate what has been read into the context of the sentence. To better understand the role of this leftward information and how it may be beneficial during reading, we compared the sizes of the leftward span for reading-matched deaf signers (n = 32) and hearing adults (n = 40) using a gaze-contingent moving window paradigm with windows of 1, 4, 7, 10, and 13 characters to the left, as well as a no-window condition. All deaf participants were prelingually and profoundly deaf, used American Sign Language (ASL) as a primary means of communication, and were exposed to ASL before age eight. Analysis of reading rates indicated that deaf readers had a leftward span of 10 characters, compared to four characters for hearing readers, and the size of the span was positively related to reading comprehension ability for deaf but not hearing readers. These findings suggest that deaf readers may engage in continued word processing of information obtained to the left of fixation, making reading more efficient, and showing a qualitatively different reading process than hearing readers.
Keywords: Perceptual span; deaf readers; eye movements; reading; word identification span.