CAJ | 학술논문

本实验使用ERPs技术,操纵情绪图片作为指示符,探讨在情绪指示下对中性名词的定向遗忘效应;根据提取阶段对项目再认的正确与否结合编码阶段的指示,将编码阶段指示符呈现时的ERPs叠加平均为4类：指示记住/记住（RR）,指示记住/忘记（RF）,指示忘记/记住（FR）,指示忘记/忘记（FF）,来考察指示上的情绪效应以及两种情绪下的记住、忘记意向。结果发现：行为结果上,两种情绪指示下均存在定向遗忘效应。350~600 ms时段,在额区和中央区位置指示记住条件（指示记住/记住和指示记住/忘记）下,正性情绪的波形比负性情绪显著更正,这一结果反映了效价评估过程,体现了对正性刺激的偏好;左侧顶区位置的指示忘记/忘记条件下,负性情绪的波形比正性情绪的波形更正,说明负性情绪指示忘记时对项目较弱的抑制作用;而指示忘记/记住条件下并不存在情绪效应。此外,正性情绪作指示时,在记住意向（指示记住/记住和指示忘记/记住）和忘记意向（指示记住/忘记和指示忘记/忘记）上都存在差异;负性情绪作指示时并不存在记忆意向上的差异。由此可见,正性情绪作指示时的加工更加灵活,且在指示忘记上更有效。
본실험사용ERPs기술,조종정서도편작위지시부,탐토재정서지시하대중성명사적정향유망효응;근거제취계단대항목재인적정학여부결합편마계단적지시,장편마계단지시부정현시적ERPs첩가평균위4류：지시기주/기주（RR）,지시기주/망기（RF）,지시망기/기주（FR）,지시망기/망기（FF）,래고찰지시상적정서효응이급량충정서하적기주、망기의향。결과발현：행위결과상,량충정서지시하균존재정향유망효응。350~600 ms시단,재액구화중앙구위치지시기주조건（지시기주/기주화지시기주/망기）하,정성정서적파형비부성정서현저경정,저일결과반영료효개평고과정,체현료대정성자격적편호;좌측정구위치적지시망기/망기조건하,부성정서적파형비정성정서적파형경정,설명부성정서지시망기시대항목교약적억제작용;이지시망기/기주조건하병불존재정서효응。차외,정성정서작지시시,재기주의향（지시기주/기주화지시망기/기주）화망기의향（지시기주/망기화지시망기/망기）상도존재차이;부성정서작지시시병불존재기억의향상적차이。유차가견,정성정서작지시시적가공경가령활,차재지시망기상경유효。
The ability to intentionally forget emotional irrelevant or unwanted materials is vital for memory function. The item method, which is the one of two main variants of directed forgetting paradigm, is the typical approach to exploring the mechanisms of intentional forgetting in the laboratory. When the item method was used, the predominant explanation of directed forgetting effects emphasizes selective encoding, while evidence supporting inhibition control during encoding and retrieval is also observed. ERPs studies on directed forgetting during encoding attempt to seek inhibition evidence and separate encoding effort from encoding success. Many studies have found that the to-be-forgotten cues elicited early enhanced positive waves in frontal and prefrontal areas, indicating strong activation of inhibitory processes. Meanwhile, intentional forgetting involves different brain areas compared with unintentional forgetting and intentional remember. ＇researches-on-directed-forgetting-of e-m-ot-io-nai-materials showed that emotional stimuli are exempt from forgetting or have a diminished directed forgetting effect when compared with neutral stimuli. Unlike previous studies on directed forgetting of emotional events with neutral symbols as cues （eg, ＂RRRR＂ as the to-be-remembered cue and ＂FFFF＂ as the to-be-forgotten cue）, the current study used emotional pictures as cues to create two experiment manipulations. The first manipulation used positive pictures as the to-be-remembered cues and negative pictures as the to-be-forgotten cues; the second used negative pictures as the to-be-remembered cues and positive pictures as the to-be-forgotten cues. The purpose of the two manipulations is to examine the electrophysiological correlates of the intentional forgetting of neutral nouns using the item-method directed forgetting paradigm. Twenty female undergraduate students participated in the experiment. During study phase, participants were instructed to remember half of a series of presented words （TBR） and to forget the other half （TBF） according the emotional picture cues. During test phase, they pressed one of the mouse buttons to indicate whether the word was presented at study phase or not. We used the behavioral recognition data to sort ERPs time-locked to the picture-cues into 4 conditions based on the combination of memory instruction and behavioral outcome： RR （TBR hit）, RF （TBR_miss）, FR （TBF_hit） and FF （TBF miss）, to investigate the emotional effects on the 4 experimental conditions and the processes underlying successful implementations of intentions to forget （i.e., RF vs. FF ） and intentions to remember （i.e., RR vs. FR）. Directed forgetting, that is reduced recognition of to-be-forgotten words, occurred for both positive picture as cues and negative conditions. At 350-600ms, it was found that positive picture as to-be-remembered cues elicited a more positive wave than negative ones （under the ＇RR＇ and the ＇RF＇ condition） in the middle frontal and central areas which are involved in the evaluation of the emotional valence of stimuli, and this result could reflect a preference toward pleasant pictures. But ERP amplitudes were larger for negative pictures compared to positive ones under the ＇FF＇ condition in the left parietal region, which suggests weaker inhibition for the item under the condition of negative pictures as ＇FF＇ cues. There were no significant differences between the positive and negative pictures under the ＇FR＇ condition. Moreover, when the positive pictures are as cues, there were significant differences between the intentional and unintentional remember conditions （＇RR＇ vs. ＇FR＇） and between the intentional and unintentional forget conditions （＇RF＇ vs. ＇FF）, whereas when the negative pictures are as cues, no such comparisons were observed to be significant. Our results show that flexible control of memory may be effective even in conditions in which negative pictures were used as cues, although it requires more effort than that in conditions using positive pictures as cues. Moreover, positive emotion is more effective as to-be-forgotten cues.