An ERP Study on the processing of negation in the category verification task

Abstract

In some previous studies,the two-step simulation hypothesis was proposed to describe the negation processing.According to the hypothesis,the comprehender first simulates the negated state of affairs and then integrates negation to build on the simulation of the actual state of affairs.In order to test this hypothesis,event-related brain potentials(ERPs) were measured when 20 Chinese subjects performed the category verification task.Four conditions were included in the task:affirmative category pair(e.g.,vegetables-cabbage),affirmative unrelated pair(e.g.,vegetables-bee),negative category pair(e.g.,vegetables-bee),negative unrelated pair(e.g.,vegetables-cabbage).The transverse line was a denial sign(e.g.,vegetables signaled something that was not vegetables).Results showed that the negative category pair elicited the more negative N400 than the negative unrelated pair and the affirmative category pair,indicating that the negated state of affairs was represented in the negation processing and hence supporting the two-step simulation hypothesis.In addition,a more positive LPC was evoked by the affirmative category pair as compared to the negative category pair,which was an ERP indication of negation integration occurring at the second stage according to the two-step simulation hypothesis.The explanation for the larger LPC by the affirmative category pair was that the processing of affirmative category pair was associated to the recognition and recollection of memory information.In contrast,the processing of negative category pair which required two stages as predicted by the two-step simulation hypothesis was associated with a reasoning process.