The Electrophysiological Effects Of The Unconscious Emotions Under Stimuli-focused And Experience-focused Approach

In the early history of psychology research, "emotion" has actually been ignored by psychologists. The psychological academia witnessed a "cognitive revolution" during the 60’s of 20 century. Since the 80’s of 20 century, the research on "emotion" has gained the attention of psychologists and has produced an increasing number of research results with great academic influence. One of the important effects is the birth of the "unconscious emotion research" in this both ancient and new research area.Although Freud’ theory about unconscious minds influenced on many fields greatly in the 20 century, but an important truth is that the researches about unconscious minds in the scientific psychology have no relations with Freud’s theory. Unconscious emotion has been developed into a new trend since Paul Rozin, a modern cognitive psychologist,brought about the concept of unconscious cognition in 1976. Actually, the origin of concept about unconscious emotion was depicted on two lines of literature, the information-processing model, which has been influential among multiple fields,suggested the necessity and importance to study the unconscious process of emotion,and unconscious emotion has been developed into a new trend since Paul Rozin, a modern cognitive psychologist, brought about the concept of unconscious cognition in1976.The information-processing model of unconscious emotion(Wiens & ?hman, 2007,shorted as Wiens Model), consistant with Coon’s theoretical model and also with some new ideas, integrated the two concepts of unconscious emoiton and implied the big challenges encountered by traditional research on unconscious emotion and the possible new trends.Wiens Model was introduced and the two approaches to study unconscious emotion,according to Wiens Model, were also discussed, in order to identify the basic nature of unconscious emotion and the effective mothods and technologies. Based on WiensModel, there were two approaches to prove the existence of unconscious emotion. One was stimulus-focused apprach, in which the input of emotional stimulus was manipulated to eliminate individuals’ awareness about the emotional stimulus while inviduals’ subsequent emotional experiences, behavioral and physiological reactions could still be recorded. The other was experience-focused approach, in which individuals’ awareness about emotional processing signals(behavioral or physiological signals) indexed the arousal of targeted emotion, while there were no self-report about changes of emotional feeling/mood.The traditional unconscious emotions studies(the stimulus-focused approach)mainly explore “backward masking + subliminal priming” paradigm to manipulate the input of emotional stimulus. The researchers suggested that by exploring this paradigm could eliminate individuals’ awareness about the emotional stimulus. If the input of the emotional stimulus was manipulated while individuals’ subsequent emotional experiences, behavioral or physiological reactions were recorded, the traditional unconscious emotions were induced. But the main debate about this approach proposed the unsolved question: How to assess the conscious level about the emotional stimulus under this approach? We deduced therefore that the new approach to study unconscious emotion should be experience-focused approach.In the experience-focused approach, the input of emotional stimulus is not important any more. The important point has been changed. If there were no self-report about changes of emotional feeling/mood, but there exist behavioral or physiological signals which could index the arousal of target emotion, the unconscious emotion could be supported. But we ask the two questions about the experience-focused unconscious emotion:(1) Could the nature of the unconscious emotion under experience-focused approach be the difference of emotion’s intensity?(2) Is there relations between the unconscious emotion under experience-focused approach and the traditional emotion?Study 1 was designed to verify the electrophysiological effects of traditional unconscious emotion priming. However, there have been increasingly debates on traditional unconscious emotion studies and there have been rarely a few experiences-focused unconscious emotion studies, with unsolved technological problems to measure the level of consciousness. Hence, the aim of present work was to explore rather than verify the experiences-focused unconscious emotion based on Study2, Study 3 and Study 4.In Study 1, the purpose was to explore the electrophysiological effects of stimulus-focused unconscious emotion priming and subliminal presentation of stimulus and backward masking paradigm was introduced. At first, the images of positive or negative emotional scenes of 20 milliseconds were tested, and then the images of the neutral faces of 800 ms after the process of fuzzy treatment were tested. The task was to determine the positive expression or negative expression of the face images. This study aimed to eliminate the consciousness of the input of the emotional stimulus, and thus to explore the electrophysiological effects of the unconscious emotion priming in the focus of stimulation.The findings of study 1 included: Firstly, the N80-120 induced by a subliminal negative scenario was more negative than the N80-120 induced by a subliminal positive scenario. Secondly, the presentation of the subliminal emotional scene could affect the judgment of the emotional valence of the fuzzy neutral face which was subsequently presented. Thirdly, the oral report of the individual was no change of any emotional experience in the preceding experiments. The results of the study confirmed that, under the condition of the present study and for most of individuals, the processing difference in the brain between the positive or negative emotional scene appeared to be 80 to 120 milliseconds after stimulus onset, and N80-120 might be the electrophysiological effect of the unconscious emotion priming.The design of Study 2 came from the very famous and controversial experiment of "little Albert" by Watson. The main finding of this experiment showed that through the classical conditioning of "fear" of and its generalization, the little boy, Albert, not only feared the white rat, but also became scared of the white rabbit, the white dog, the white fur coat and so on, which had the common features such as "white fluffy" and had been neutral stimulus for himself before experiments. Inspired by this experiment, we used the ERP technology, on the basis of Wiens Model, to explore the electrophysiological effects of unconscious emotional priming following the experiences-focused approach and to avoid such experimental trauma as the small Albert experiment did.Specifically, we selected the A three-digit Arabia numbers as neutral stimuli and the emotional faces to be the unconditional stimuli. In the conditioning stage of experiment,these two types of stimuli were paired with to be tested. After 56 x 5 such trials, in thetesting phase some numbers(three types of three-digit Arabia numbers) were presented and the task was only to judge whether the numbers on the screen appeared in the learning phase or not(implicit emotional task)? In this study, a total of three experimental conditions(pleasant emotional condition, neutral emotional condition, sad emotional condition) were studied.The main findings of study 2 showed two facts: Firstly, LPC300-600 induced by Type 2 numbers in the sad condition, compared to LPC300-600 induced by Type 2numbers in the neutral condition, were significantly more negative. Secondly,LPC300-600 induced by Type 2 numbers under the pleasant conditions, compared to under the neutral condition, were not significantly different. Combined with the oral report in Study 2, the findings implied that LPC300-600 should be likely to be one index of the electrophysiological effects of unconscious emotion in experience-focused approach.In Study 3 the implicit emotional task paradigm was applied with different experimental materials and experimental procedures, to further verify the results of the study 2. Specifically, four characters Chinese idioms including the concepts of self-confidence or self-conceit were randomly presented, the task was to determine the four characters Chinese idioms on the screen to show the concept of confidence or conceit. The purpose of this study was to further explore the electrophysiological effects of unconscious emotion priming by using different implicit emotion paradigm involving different experimental materials and procedures from that in Study 2, and to verify the electrophysiological effects of the unconscious emotion priming in experience-focused approach in Study 2.The findings of the electrophysiological effects in Study 3 showed that LPC470-570 wave amplitude induced by idioms of self-conceit, compared to by idioms of self-confidence, was significantly more positive. In combination with the oral report in Study 3, the findings implied that LPC470–570 should be likely to be one index of the electrophysiological effects of unconscious emotion in experience-focused approach.In Study 4 the implicit emotional task paradigm was also applied with different experimental materials and experimental procedures, to further verify the results of the Study 2 and Study 3. To be specific, in this research condition, the test presented the earth human face picture or the alien face picture with random orders and the task was to determine whether the picture on the screen to be the earth or aliens, which did notrelate with the emotional category judgment task so that active emotion processing was not required and therefore the "implicit emotional task" in Study 4 was produced.The findings showed that LPC200–450 wave amplitude induced by the alien face picture, compared to by the earth human face picture, was significantly more negative.In combination with the oral report in Study 4, the findings implied that LPC200–450should be likely to be one index of the electrophysiological effects of unconscious emotion in experience-focused approach.In summary, combined the results of the four studies and the theoretical inspiration of Wiens Model, we have come to the conclusions as follows:(1) N80-120 probably indexes the electrophysiological effects of unconscious emotion in stimulus-focused approach in Wiens model.(2) An early late positive component(LPC) probably indexes the electrophysiological effects of the unconscious emotion priming in experience-focused approach in Wiens Model,.(3) In Wiens Model, the brain processing mechanism of unconscious emotion may be different between stimulus-focused approach and experience-focused approach.(4) Given the similarity and difference between the early "LPC" and traditional "LPC" in present studies, we inferred that, in Wiens Model unconscious emotion in experience-focused approach had, to certain degree, connection with the traditional conscious emotion.In the end, the future directions of unconscious emotion research were also discussed.