Bernhard Angele of Bournemouth University (UK) will give the Brown Bag presentation on Wednesday March 23 from 12-1:20 in Tobin 521B. A title and abstract of his talk follows.
They’re onto us! The phenomenon of participants detecting display changes and what it can tell us about the reading process
In the boundary change paradigm (Rayner, 1975), when a reader's eyes cross an invisible boundary location, a preview word is replaced by a target word. Readers are generally unaware of such changes due to saccadic suppression. However, some readers detect changes on a few trials and a small percentage of them detect many changes. I will present three experiments which combined eye movement data with signal detection analyses to investigate display change detection. On each trial, readers had to indicate if they saw a display change in addition to reading for meaning. On half the trials the display change occurred during the saccade (immediate condition); on the other half, it was slowed by 15–25 ms (delay condition) to increase the likelihood that achange would be detected; we also manipulated the properties of the parafoveal preview word. Using this new paradigm, we found that subjects were (1) highly sensitive to display change delays, and (2) more sensitive to display changes which involved a change of letter identity (e.g. jNxVa to gReEn) than to display changes which involved a change of visual features, but kept letter identity constant (e.g. gReEn to GrEeN). Finally, (3) subjects were significantly more sensitive to display changes when the change was from a non-wordlike preview (xbtchp to garden) than when the change was from a wordlike preview (puvtur to garden), but the preview benefit effect on the target word was not affected by whether the preview was wordlike or non-wordlike. Additionally, we did not find any influence of pre-boundary wordfrequency on display change detection performance. Our results suggest that display change detection and lexical processing do not use the same cognitive mechanisms. We propose that parafoveal processing takes place in two stages: an early, orthography-based, pre-attentional stage, and a late, attention-dependent lexical access stage.