The Role of mental simulation in language comprehension

The mechanism of language comprehension is a fundamental issue in the psychological field. The amodal theory hypothesizes that semantic knowledge is represented in the human mind as arbitrary symbols which can form larger units such as the feature list,frame,schema and semantic nets. The embodied theory,which is based on the Hebb learning theory and mirror neuron studies,claims the view contrary to the amodal theory.In the embodied view,semantic knowledge is represented in the human mind as the mental simulation of the corresponding sensory-motor processing,and when semantic knowledge is processed,the neural system responsible for the actual sensory-motor processing is involved. The representative view of the embodied theory includes the perceptual symbol system view(Barsalou,1999),the neural theory of language(Feldman and Narayanan,2004) and the language and situation simulation theory(Simmons et al.,2008). The perceptual symbol system view holds that the sensory-motor system can capture the perception information from the outside world and the inside world.The perceptual signals are the simulation of the information. The neural theory of language maintains that semantic knowledge learning is based on the interaction of the human body and the outside environment,and word meaning is represented as the simulation of the described situation.Figurative language and arbitrary words can get their meaning from the concrete words. The language and situation simulation theory claims that both linguistic system and situation simulation system engage in language processing. The linguistic system is responsible for the word form processing and is activated earlier. When the linguistic system is activated,the simulation system is activated too,simulating the perceptual,motor,and mental situation depicted by the language. Researchers conducted many behavioral and neuroimaging studies to explore the role of mental simulation in language comprehension. Behavioral studies found that the sensory features of a word could influence the judgment of word meaning,and language comprehension had interaction with the actual sensory-motor process. The Neuropsychological studies showed that patients could not process action verbs well if their motor areas were destroyed.TMS studies indicated that when the participants were processing action verbs,the potentials from the corresponding motor areas were influenced. The ERP and fMRI studies found when participants were reading or listening to concrete nouns or action verbs,the corresponding sensory-motor areas were activated. In a word,all these studies showed that during language comprehension,the sensory-motor system is involved automatically. The future theory of the embodied semantic view should make clearer hypothesis about how the mental simulation engages in language comprehension.It should also include the interaction between mental simulation and semantic integration,inhibition and selection,as well as the interaction between word form processing and different levels of simulation. Future studies should pay more attention to the inconsistent results found by recent studies,which may indicate that the mechanism of mental simulation is very complex and more efforts should be made to explore the internal process of simulation.In addition,how the meaning of figurative language is accessed still needs more exploration.