Effects Of Emotional Valence And Self-reference On The Old/new Effects Of Episodic Memory

Whether the retrieval of episodic memory,comprising item memory and source memory as two subtypes,is based on the single intensity change of memory(single-process model)or two relative dependent processes(dual-process model)has always been a hot topic.Episodic memory can be influenced by emotional valence.Previous ERP study has mainly focused on the influence of the emotional valence on item memory's old/new effects.But few has studied the modulation of emotional valence on source memory's old/new effects(especially late old/new effects).Besides,the self-reference effect(SRE)is also reported in behavioral studies of episodic memory,which claims better performances when the material is connected with oneself.Although the emotional valence and self-reference have an impact on episodic memory respectively,SRE may be regulated by emotional valence when these two factors work together on episodic memory(i.e.,individuals are more inclined to connect positive information with self to maintain a positive self-schema).However,current sutdy only stays at the behavioral level,no effort has been put into exploring how SRE affects the old/new effects under different emotional valence conditions,as well as various cognitive processes involved in the ERP study(familiarity,recollection,reconstruction,post-extraction monitoring and etc.).Therefore,this study aims to explore the relationship among the emotional valence,self-reference,and episodic memory' old/new effect through answering two questions.One is how the emotional valence affects the late old/new effects of episodic memory.The other is whether there is a source SRE for source memory's old/new effects and whether source SRE is regulated by the emotional valence or not.In order to address the above issues,the ERP technique was employed to two experiments adopting emotional words(positive,neutral,and negative)as stimuli.Experiment 1 used word colors(red and green)as sources to induce late old/new effects,and participants were instructed to perform item memory task or source memory task in random.Results showed that,both memory taks found evident FN400 and early-LPC for three valences and both components performed no difference among valences;late-LPC was only significant in source memory task with no difference among three valences;LPN was absent in item memory,but recorded for negative words in source memory.Experimen t 2 used a self-referential task(to determine whether I like the word)and a self-external task(to determine whether this word was common)as sources,and hereafter a source memory task.Results showed that,FN400 and LPC showed no source SRE for three valences;LPN proved an adverse-source SRE for emotional valences and LPN showed no source SRE for neutral valence;RFE was only evident in emotional valences with neutral valence vacant,and RFE proved an adverse-source SRE for emotional valences.The main conclusions of this study are as follows:(1)Emotional valence modulated the late old/new effects of episodic memory and there exsited between memory tasks sensitity,which stands for the dual-p rocess model.(2)Self-reference and emotional valence don't affect the early old/new effects of source memory;self-reference and emotional valence both modulate the late old/new effects of source memory together.