Long-range reading regressions are accompanied by a P600-like brain potential: Evidence from the co-registration of ERPs and eye movements
About 15% of reading saccades move the eyes backwards in the text. To study the neurophysiological correlates of such regressions, we co-registered gaze position and ERPs of 54 subjects during natural, left-to-right reading. Sentences were grammatically diverse but contained no syntactic violations or local ambiguities. Accompanying the onset of long-range regressions, we observed a late centroparietal positivity, closely resembling the P600 component commonly observed for syntactic violations and garden-path sentences in traditional ERP experiments. This suggests that the P600 indexes individual comprehension difficulty or parsing problems even in the absence of syntactic ambiguity. Co-registration of eye movements and ERPs may help to differentiate between regressions caused by oculomotor overshoot, word identification failures, and syntactic parsing problems.
The abstract of this poster was published in the Journal of Eye Movement Research, Vol. 1, Number 5, p. 129.
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