Abstract
What is the delay in processing a word you have just read, and how does it change through the course of a sentence? To answer these questions, we developed a new paradigm for measuring the time course of semantic processing with respect to fixations while reading. On each trial, observers read a four-word sentence that changed color continuously through a circular set of hues. Observers were then shown a response palette arranged in an annulus and instructed to select the perceived color of a randomly selected (precued) word at the time that they read it. In addition, observers categorized the statement as either true or false which necessitated encoding all four words. Trial duration was adaptively controlled to ensure that subjects had sufficient time to read the sentence, while minimizing re-fixations. In a non-reading baseline condition, sentences were replaced with horizontal bars, divided into outlined regions corresponding to locations of previously seen words. Observers reproduced their eye movements from the reading task by tracking a crosshair positioned at previously fixated locations. At the end of the trial, subjects performed the same color reporting task. For both the reading and non-reading conditions, we measured the latency between the beginning of the observer's first fixation on the word and the time point in the trial corresponding to the reported color. Results showed distinct patterns of temporal lags in the two conditions—while response delays in the non-reading task remained constant as a function of their position the sequence, delays in the reading task were greater for words earlier in the sentence than for words later in the sentence. Together, our results demonstrate a new method for examining the dynamics of information processing, and point to contextual influences on semantic processing delays with respect to fixations during reading.
Meeting abstract presented at VSS 2016