The processing of presuppositional information contained in sentences: electrophysiological correlates.

In an attempt to observe how the brain processes presuppositional information, event-related potentials (ERPs) were recorded from 12 scalp electrodes placed over the left and right hemispheres of 10 adult subjects as they listened to sentences that contained either factive or nonfactive verbs. The stimulus sentences had been time-compressed to a duration of less than 1.25 sec, allowing ERPs to be recorded over their entire length. A Principal Components Analysis/Analysis of Variance procedure provided evidence that the brain responses could discriminate between factive and nonfactive conditions. It was concluded that the processing of presupposition represents a multidimensional phenomenon that changes across cortical space and time.