An ERPs Study On The Semantic Processing Of Chinese Evidential Causals And Conditionals

Causal relation and conditional relation are essential in our daily life.Many scholars have studied causals and conditionals.Most previous studies researched on causals,conditionals and the relations between these two from the perspective of cognitive pragmatics,semantics,syntax and Corpus linguistics.Sander et al.(1992)regard conditionals as a subcategory of causals.Hoek et al.(2017)claim that causal relations tend to be implicitly marked while conditional relations tend to be explicitly marked.And coherence relation which is easier to grasp is always expressed implicitly.Conditionals are involved in mental shifting while casuals are not.Readers need to finish a mental shifting from an implied factual space to an explicit hypothetical space.We also find that few studies focus on the study of evidential causals and evidential conditionals and most of them are theoretical studies while few are empirical studies.According to the classification of Liao(2004)and Xu(2004),the present study adopts ERPs technique and interprets the cognitive differences between evidential causals and conditionals with the help of Mental Space Theory(Fauconnier,1985),and the research question is what are the cognitive differences of processing evidential causals and conditionals.The experiment is conducted in the Key Lab of Cognitive Neuroscience and Foreign Language Learning in SISU,Chongqing.Twenty postgraduates from SISU are selected as the subjects whose major is English.A one-factor within-subjects design with two levels is adopted,and all the materials are Chinese.The way of presenting within a sentence is according to meaning group and all the experimental materials are presented randomly.The subjects are required to understand the sentences seriously within fixed time and judge the acceptability when the last meaning group presented,and then press the button(3=totally acceptable,2=basically acceptable,1=totally unacceptable).The software E-prime 2.0 is used to present the materials.The ERPs data which will be analyzed in an off-line way are collected and recorded by the software Neuroscan 4.5.And then the outcomes are analyzed by statistic software SPSS 23.0.The outcomes are listed as below:(1)According to the behavioral results,the mean reaction time of evidential causals is 1979.72 ms and that of evidential conditionals is 2031.93 ms.There are no significant differences [p=.499>.05] between them.(2)According to the ERPs data,significant difference [p=.044<.05] exists between the amplitude of slow wave elicited by evidential causals and conditionals in the time window 1000ms-3200 ms and the slow waveforms elicited by evidential conditionals(-4.459 ± 0.943)are more negative than that elicited by evidential causals(-2.344 ± 0.924).These differences exist in the left central region [p=.086 < 0.1],middle central region [p=.038<.05],middle parietal region [p=.036 <.05] and right parietal region [p=.016 <.05].The main differences are elicited in the time window of 2200ms-3200 ms [p=0.55<0.1].(3)The Slow Wave effect is different in the left and right hemispheres.The results show that there are significant differences in the right hemisphere [p=.043<.05].The present study draws the following conclusions: participants spend more processing time in comprehending evidential conditionals.Participants spend more processing efforts in comprehending evidential conditionals and it empirically proves that comprehending of conditionals involves mental shifting.The differences between evidential causals and evidential conditionals lie in the central and parietal regions and the right hemisphere.