Effect Of Valence,Arousal,And Motivational Dimension On Selective Memory For Complex Emotional Scenes:Evidence From Behavioral And ERP Studies

When we invastigate memory for details of the complex emotional stimuli,we found the weapon focus effect(Saunders,2009),emotional induced memory narrowing effect(Levine&Edelstein,2009)or central/peripheral memory trade-off effect(Steinmetz&Kensinger,2013)and other selective memory(memory selectivity)phenomenon.Emotional arousal leads to memory enhancement of central information,and impaires memory for peripheral information.So which factors and how would influence emotion induced memory selectivity.What is time course of this selective meory processing?This dissertation attempts to answer these questions.First,according to two theoretical models called motivational dimension model-of emotion and goal-relevance approach to explain emotional memory trade-off effects,preparation and evaluation of complex emotional scenes were finished giving to the dimension of valence(pleasure),arousal,survival relatedness(motivational dimension),visual complexity,scene coherence.We try to use the more comprehensive assessment of emotional scene components(e.g.central and background component)in order to screen and select experimental stimuli.Then,mixed design(Between-Subject variable:arousal,Within-Subject:valence and motivational dimension)and study-recognition paradigm were used in three behavioral experiments and three event-related brain potentials(ERPs)experiments.Memory performance and neuroelectrophysiological indicators were used to examine the time course of complex emotional scene induced memory trade-off effect,the effect of valence,arousal,motivational dimension on cognitive and neural mechanisms of selective memory.Major behavioral results are:1)High arousal negative emotions evoked scenes central/peripheral memory trade-off effect,resulting in a selective memory enhancement of negative central items and memory discreasement of surrounding backgrounds;2)Low arousal level of positive and negative emotions did not evoke memory trade-off effect,but low arousal negative items evoked item memory enhancement;3)Using delicious food and sports scenes as high and low motivational scenes respectively,we found the expected memory trade-off effect induced by the high motivational-dimension scenes,but no memory broadening effect induced by low motivational-dimension scenes;4)General high arousal positive emotions which were not be calssified into motivational dimension evoked scenes can not evoke center/peripheral memory trade-off effect,but only lead to positive item memory enhancement.Major ERP results are:1)In the late stage(500-800ms)on the right parietal region,there is a memory trade-off effect evoked by high arousal negative emotional scenes,that is,negative emotions enhanced item recollection and impaired background recollection;2)In the early stage(300-500ms)on frontal region and in late stage(500-800ms)on parietal region,we did not find low arousal positive and negative emotional scenes evoked central/peripheral memory trade-offs effect;3)In the late stage(500-800ms)on right parietal region,we found a significant central/peripheral memory tradeoff effect induced by emotional scenes of high motivational dimension.Such behavioral and ERP results in this dissertation provided more evidences about the effect of valence,arousal and motivational dimension on memory selectivity.Some preliminary conclusions can be drawn:1)At high aoural level,the negative valence is the critical factors determing the presence or absence of memory trade-offs.And in the low arousal level,whether positive or negative valence can not induce central/peripheral memory trade-off effect;2)High arousal positive emotions also can evoke central/peripheral memory tradeoff effect,but only limited in positive emotions of high motivational dimension;3)The late stage(500-800ms)of parietal region is sensitive to central/peripheral memory trade-off effect.