| Consciousness is the basis of human mental activities.It is considered as an important scientific question to be answered in the 21 st century.The research on the degree and limits of visual unconscious processing is the premise of better understanding conscious processing.Language and consciousness have always gone hand in hand,but the exact role of consciousness in understanding language remains unclear.What level of language processing can be achieved without consciousness is controversial among scientists.Chinese characters have a long history and unique orthographic characteristics.It is of great significance to study the scope and level of unconscious processing of Chinese characters to clarify the relationship between language and consciousness.This thesis studies the modulation of two kinds of unconsciousness(subliminal and and preconscious)on multi-level visual processing of Chinese characters(single-character word,two-character word and short sentence)by using the psychophysiological experimental method--breaking continuous flash suppression(b-CFS)paradigm.The main content includes three research questions involving six independent experiments.The first research question is whether we can unconsciously process the metaphorical meaning of Chinese phrases and double-character words? Using the bottom-up CFS and non-CFS contrast paradigm based on stimulus content,we manipulated the semantic relations(metaphorical,literal or abnormal)and the shapes of Chinese characters(upright or inverted),and investigated the unconscious processing mechanism of metaphorical sentences and spatial metaphorical words respectively through two independent experiments(Experiment 1-2).The results showed that the metaphoric meaning(even literal)couldn't get processed subliminally by breaking through the interocular suppression,but under the state of preconsciousness,the metaphor meaning could get partial processing: metaphoric phrases broke through CFS suppression more quickly than the literal ones,while words of spacial metaphor made no difference in terms of suppression time compared with words of literal meaning.The invertion effect of Chinese characters occurred steadily in the subliminal state,that is,all the upright sentences or words entered consciousness faster than the inverted ones,but the complex interaction between the shape and semantics might cause the invertion effect to disappear in the pre-conscious state.The second question is whether the emotional information of Chinese characters could be processed unconsciously? Using the same CFS contrast paradigm and two independent experiments(with two-character words or single-character words),we manipulated the emotional valence(negative or neutral)and the shape of Chinese characters(upright or inverted),and investigated the unconscious processing of emotionlabeled words and emotion-loaded words.The results showed that in the subliminal state,the emotional information either in two-character or single-character words would not affect the time needed to break through the interocular suppression,while the invertion effect of Chinese characters occured steadily with the upright word entering the consciousness faster than the inverted ones.On the other hand,in the pre-consciousness,there was a difference in breakthrough time between single-character negative words and neutral words: the detection speed of the former was significantly slower than that of the latter but the invertion effect disappeared.These results showed that although some of the emotional information could be processed in the case of preconsciousness,the emotional information in Chinese characters could not be effectively processed subliminally.The automatic vigilance effect could't be verified in this research.The third question is whether word form and meaning have priming effects on the unconscious processing of Chinese characters? Using the top-down priming-CFS paradigm based on the stimuli's environment,we manipulated both mophological and semantic prime-target association and investigated the influence of word form and semantics on the suppression time of Chinese characters in CFS masking.The results showed that,under subliminal state,the target words which were semantically or morphologically related to the primes broke through interocular suppression and entered the consciousness at a significantly faster rate than those which were not related.On the other hand,the priming effect did not extend to the pre-conscious state.In addition,we also found that under subliminal unconsciousness,semantic and morphological priming had different patterns between two-character words and single-character words.Either semantic or morphological relatedness of two-character words could positively promote their unconscious processing,but the priming effect disappeared due to some cognitive competition when the prime and the target were both morphologically and semantically related.Negative priming effect existed when the single-character prime and target shared the same parts(radicals).The priming effect was not obvious when there was only semantic relatedness,but when there was a combination of morphological and semantic relatedness,the priming effect reversed and the process of the target breaking through interocular suppression would be speeded up.To sum up,this thesis managed to draw the following three main conclusions.On the one hand,preconsciousness or partial awareness is essential for high-level cognitive activities such as reading comprehension.In subliminal state,Chinese script could be successfully processed at the low-level of orthography,but not up to the conceptual or semantic level in either single-character or double-character words or short sentences,whether it was embodied metaphoric meaning,or evolution-related emotional meaning,even the literal meaning.However,all of these meanings could be processed to a certain degree in the pre-conscious state.Our research supports the distinction between the subliminal and the preconscious in the framework of the global neuron workspace theory(GNWT),and highlights the importance of preconsciousness or partial awareness in maintaining mental health and facilitating clinical rehabilitation.On the other hand,our research confirms the interaction between consciousness and unconsciousness.Top-down conscious reading experience can improve the level of unconscious Chinese character processing.In addition,the emergence of special patterns,such as the invertion effect,the opposite priming effects related to form and semantics,is closely related to the unique orthography of Chinese characters.This study is of great value for the establishment of the unconscious visual processing model of Chinese characters,the in-depth understanding of the interaction mechanism between visual consciousness and unconsciousness,and the expansion of the cross-language research under the natural science path.In the future,with brain imaging technologies such as event-related potentials(ERP),functional magnetic resonance imaging(fMRI)and transcranial magnetic stimulation(TMS),we will compare a variety of research paradigms(CFS,Visual Masking,Attentional Blink,etc.)in investigating the mechanism of automatic processing in Chinese characters or bilingualism,and exploring the potential value of clinical applications relevant to consciousness. |
PDF Full Text Request