新颖性图像加工的时间进程

An ERP Study on the Time Course of Pictorial Novelty Processing

采用ERPs技术，考察了个体新颖性图像加工的时间进程。行为结果表明：新颖性图像的判断时间更长。ERPs结果显示：新颖与非新颖图像在刺激呈现后190～340ms诱发出明显的前额区N190～340，但在波幅上无显著差异；在400-600ms以及600-1000ms，新颖性图像在顶区与额一中央区，特别在右侧半球诱发出更大的正性偏移（P400～600和LPC）。研究表明：图像新颖性属性的识别主要发生在涉及图像特征融合、图像记忆编码等多项认知活动参与的晚期加工阶段，并存在半球右侧化效应。

Novelty processing is a process that individuals perceive and recognize the novelty of given products or ideas. Many theories about creativity hold that novelty processing is one of the key factors in the structural and multiple studies of creativity and have found a significantly positive correlation between novelty processing and creativity. It is undeniable that novelty processing is useful for detecting creative information and facilitating highly creative performance. This process has gradually attracted researchers＇ attention. Some researchers have also studied the neural correlates of this process in greater detail. Researchers have previously investigated the neural correlates of the spatial dimension of novelty processing and identified brain activation patterns by using functional magnetic resonance imaging （fMRI） techniques. For instance, the previous studies found not only that novelty processing was associated with object identification （fusiform cortex）, working memory （prefrontal cortex）, and spatial attention （parietal cortex） but also that the left precuneus was associated with the integration of unusual features of novel objects, while the right visual cortex was sensitive to the detection of such features. However, due to the limitation of low temporal resolution, those brain imaging results were unable to depict the relationships between the cognitive activities involved in novelty processing. There is also an open question about the temporal dynamics for our brain to realize the novel attribution of the picture stimulus. Does it begin with the perception？ To overcome these shortages, the present study used event-related potentials （ERPs） to explore the temporal dimension of hOVe! object processing by collecting the time course data of this process. The present study collected the time course data during the processing of novel pictures by Event-related potentials （ERPs） due to its excellent temporal resolution. Based on the findings Of a previous＇ study and the definition of novelty, whereby novelty was assumed to come from the combination of the existing concepts or features, novel stimuli in this study were constructed by combining different features of the existing non-novel objects （e.g., ＂the bird body has an elephant head＂）. At the same time, to ensure that novel objects could be processed effectively by individuals and that the experiment could encompass the entire process, we used a novelty telling and judging task, which not only required participants to perceive the stimuli but also asked them to judge whether the presented stimuli were novel, based on their own comprehension. Twenty-five junior undergraduates （12 male, 13 female, average age 20.7） participated as paid volunteers. The behavior results showed that the participants spent more time evaluating the novel materials than they did on the non-novel ones. Scalp ERPs analysis revealed that although novel and non-novel pictures were elicited anterior N190-340, their amplitudes had no significant differences in statistics, which might suggest that individuals could not distinguish those two types of stimuli at the early perception stage for object features recognition. However, novel image elicited a more positive ERP deflection than non-novel ones did between 400~600ms （P400-600） with the right centro-parietal scalp distribution, which might reflect the process of representing the novelty in the working memory and might suggest that processing the novel pictures could upload the capacity for work memory. Later, novel objects elicited a more positive ERP deflection （LPC） than non-novel ones did between 600 and 1000ms with the right anterior-central scalp distribution, which might reflect the process for participants to classify the stimuli and prepare to respond. Those results might suggest that processing novel pictures were more complex which happened after the early perception stage and involved the integration of object features and working memory encoding. The novelty processing showed the right lateralization of the brain.