Abstract
Oculomotor inhibition of return (O-IOR) is an increase in saccade latency prior to an eye movement to a recently fixated location compared to other locations. To investigate O-IOR in reading, subjects participated in two conditions while their eye movements were recorded: normal reading, and mindless reading in which words were replaced by equivalent geometric shapes. We investigated the manifestation of O-IOR in reading, and whether it is related to extracting meaning from the text or is a purely oculomotor phenomenon. The results indicated that fixation durations prior to a saccade returning to the last fixated word were longer than to other words, consistent with O-IOR. Furthermore, this effect was spatially specific: Fixation durations were longest prior to a saccade that returned the eyes to the character in the word that had previously been fixated, and dropped off as the distance between the previously fixated character and landing position increased. This result is consistent with the hypothesis that IOR is applied to the fixated character location during reading and drops off as a spatial gradient. Both of these results were found for text reading and for mindless reading, suggesting that they are consequences of oculomotor control and not of language processing. Finally, although the temporal IOR effects were robust, no spatial consequences of IOR were observed: Previously fixated words and characters were as likely to be re-fixated as new words and characters.
Meeting abstract presented at VSS 2012