关键词: 发散思维, 序列位置效应, 创新想法, 动态性, 神经机制

Abstract:

The serial order effect in divergent thinking (DT) is one of the most robust findings in the field of creativity research. This effect refers to the phenomenon that the number of generated ideas decreases, whereas the originality of ideas increases across time while performing DT tasks. A body of studies showed that the serial order effect can be evidenced in a range of age samples, various types of divergent thinking tasks, and different scoring methods.

There are two possible explanations for the occurrence of the serial order effect. Mednick's association theory indicates that the generation of creative ideas is an automatic retrieval process that spatially follows a progressive search pattern from the spread activation of proximal concepts to distant ones. This activation pattern will gradually spread over time from close, obvious associations to distant, unusual associations, thus the quality of ideas gradually shifts from conventional to novel. In addition, the association theory emphasizes that the structure of an individual's semantic network is critical for the generation of novel ideas. For example, individuals with a flexible semantic network are more capable of coming up with novel ideas. On the other hand, a growing number of studies supported that top-down control processing is the key to the emergence of the serial order effect during DT. Relevant findings were mainly focused on: (1) the selection and use of strategies during idea generation leading to the serial order effect, (2) category switching during idea generation leading to the serial order effect, and (3) executive functions related to the serial order effect of divergent thinking. In conclusion, the association theory and the executive control hypothesis focus on explaining individual differences in the serial order effect and cognitive processing, respectively.

Several neuroimaging studies have shown the executive control network centered over the dorsolateral prefrontal cortex that connects with the semantic memory-related lateral temporal cortex to suppress obvious and conventional ideas at the early stage of idea generation. With the decreasing interference from obvious and conventional ideas over time, the semantic retrieval space, the semantic distance of cues and concepts retrieving would gradually increase. During the process, the executive control network centered over the dorsolateral prefrontal cortex shifts its function to controlled semantic retrieval therefore select and evaluate for potential ideas in the working memory space. The pattern of neural activation is manifested by the executive control network coupling with the default mode network, specifically the co-activation of the dorsolateral prefrontal cortex, the inferior frontal gyrus, the dorsomedial prefrontal cortex, and the hippocampus which is subordinate to the default mode network. However, there are relatively few studies on the neuronal mechanisms underlying the serial order effect, and these studies mainly focus on the cognitive processes of single idea generation. Thus far, the current explanatory framework mostly employed cognitive and neuroimaging findings on creative thinking. Future research needs to combine cognitive and computational models, semantic analysis, brain dynamic analytical approaches, and representational similarity analysis to explore the cognitive and neural mechanisms of the serial order effect, as to provide a new perspective for deconstructing the dynamic process of creative thinking.

Key words: divergent thinking, serial order effect, creative idea, dynamic processes, neural mechanism