University of La Laguna, Canary Islands, Spain.
Brain Res. 2012 May 21;1455:40-55. doi: 10.1016/j.brainres.2012.03.032. Epub 2012 Mar 21.
This study provides ERP and oscillatory dynamics data associated with the comprehension of narratives involving counterfactual events. Participants were given short stories describing an initial situation ("Marta wanted to plant flowers in her garden…."), followed by a critical sentence describing a new situation in either a factual ("Since she found a spade, she started to dig a hole") or counterfactual format ("If she had found a spade, she would have started to dig a hole"), and then a continuation sentence that was either related to the initial situation ("she bought a spade") or to the new one ("she planted roses"). The ERPs recorded for the continuation sentences related to the initial situation showed larger negativity after factuals than after counterfactuals, suggesting that the counterfactual's presupposition - the events did not occur - prevents updating the here-and-now of discourse. By contrast, continuation sentences related to the new situation elicited similar ERPs under both factual and counterfactual contexts, suggesting that counterfactuals also activate momentarily an alternative "as if" meaning. However, the reduction of gamma power following counterfactuals, suggests that the "as if" meaning is not integrated into the discourse, nor does it contribute to semantic unification processes.
本研究提供了与理解涉及反事实事件的叙述相关的 ERP 和振荡动力学数据。参与者阅读了描述初始情况的短篇小说（“玛尔塔想在她的花园里种花……”），然后是一句关键句，以事实（“因为她找到了一把铲子，所以她开始挖一个洞”）或反事实（“如果她找到了一把铲子，她就会开始挖一个洞”）的新情况描述，然后是一个延续句，与初始情况（“她买了一把铲子”）或新情况（“她种了玫瑰”）有关。与初始情况有关的延续句的 ERP 记录显示，在事实之后比在反事实之后的负性更大，这表明反事实的前提——事件没有发生——阻止了话语的即时更新。相比之下，在事实和反事实两种情况下，与新情况有关的延续句引起的 ERP 相似，这表明反事实也暂时激活了一个替代的“假设”意义。然而，反事实后伽马功率的降低表明，“假设”意义没有融入话语，也没有促进语义统一过程。
