物体颜色对情景记忆的影响

本研究采用ERP技术和学习-再认范式考察视觉输入的颜色和记忆中的物体颜色知识一致性对情景记忆编码和提取的影响。结果显示, 在对物体图片进行编码时颜色不一致图片诱发更大N400, 而提取阶段则对颜色一致图片有更多熟悉性加工(实验1); 物体名称能够更快激活典型颜色知识, 对颜色一致名称有更多细节回想(LPC更正) (实验2)。实验结果表明, 颜色一致促进知觉水平的记忆编码, 而阻碍语义水平编码。同时, 颜色一致促进物体图片提取(知觉水平)中的熟悉性和回想过程; 而对物体名称提取(概念水平)的促进作用仅表现在回想上。此外, 颜色与物体名称有着密切联系, 同样影响物体的语义表征, 支持激活-扩散模型理论。本研究从知觉和概念水平上为揭示物体颜色在联结记忆中的作用提供了证据。

Neural mechanism underlying the effects of object color on episodic memory

Color diagnosticity is the degree to which a color is associated with or symbolizes a particular object.Typical color is often associated with high color diagnostic objects and activates the visual(perceptual)or semantic(conceptual)knowledge in long-term memory.However,the relationship between different processing levels(perceptual and conceptual)of object color information and episodic memory retrieval components(familiarity and recollection)remains poorly understood.It is hypothesized that color information can facilitate memory encoding at the perceptual level but inhibit it at the conceptual level.In recognition retrieval,color has a greater impact on familiarity and recollection at the perceptual level,while at the conceptual level,recollection is more affected than familiarity.In the present study,event-related potential(ERP)and a study-test paradigm were used to investigate the effects of color consistency(visual color input and object color knowledge)on episodic memory encoding and retrieval by using pictures and names of objects with high color diagnosticity.Twenty-seven college students participated in experiment 1.During the study phase,a picture of an object in its diagnostic color(such as a red apple)or non-diagnostic color(purple banana)was presented on a white background for 500ms.The participants were asked to determine whether the color of the object in each picture was consistent with its actual(diagnostic)color.During the test phase,participants provided old/new judgments about the objects that had appeared in the study phase and the equal number of new items.Twenty-five college students participated in the experiment.A similar procedure was used for experiment two,except that items were the names of the objects in their diagnostic or non-diagnostic color rather than pictures.During both experiments,the participants responded by pressing a mouse button.Their reaction time and EEG(electroencephalography)were recorded.The results of experiment 1 showed that,during the encoding phase,color-inconsistent objects were identified less accurately and more slowly,and this triggered a larger N400 than the color-consistent ones.During the retrieval phase the color-consistent objects were recalled more quickly and accurately,and this triggered larger FN400(frontal negativity)values than the color-inconsistent objects.However,the opposite effects were observed in experiment 2.Color-inconsistent object names were identified more quickly and accurately,and they elicited the same ERP wave as the color-consistent names.During the recognition stage,the color had an effect only during the period of late positive components(LPCs).In conclusion,color was found to have different effects on encoding and retrieval of episodic memory at both perceptual and semantic levels.(1)Color had different effects on item coding at the perceptual and semantic levels.Color consistency was found to help the viewer identify objects at the perceptual level,but it hindered object identification at the semantic level.(2)Color congruence was here found to promote familiarity and recollection in object retrieval(perceptual level),but it only improved recollection of an object’s name(conceptual level).(3)The consistency effect in the processing of object name recognition showed that color is closely related to object name,and it also affects the semantic representation of objects,which further supports the spreading activation model.