Abstract:  Forming novel associations is one of the key subprocesses in creative thinking. According to the generation-selection model of creativity and the theory of coarse semantic coding in right hemisphere, the right brain may play a dominating role in forming novel associations. However, this inference is only supported by half of the neuroimaging studies, and the others emphasize the role of left hemisphere or both. The disagreement among previous studies might result from different materials and different task requirements they used. The right hemispheric dominance in forming novel semantic associations may be more easily detected in the tasks of comprehending creative language. In the current study, the Chinese two-part allegorical sayings as well as fMRI and ERPs were used to explore the temporal and spatial features of neural processing in forming novel semantic associations. Two experiments were conducted in this study. In Experiment 1, participants were asked to read silently some Chinese two-part allegorical sayings and keep them in mind. For half of the experimental materials, the semantic association between the two parts was novel, while for the other half, it was normal. The neural activity was recorded by fMRI. In Experiment 2, the experimental materials were similar with those in Experiment 1, except for some filling materials in which there was not semantic association between the two parts. Participants were asked to judge whether the first part was associated with the second part in meaning, and the neural activity was recorded by ERP. The result of Experiment 1 showed that compared with normal semantic association, novel semantic association activated more in right superior temporal gyrus, which was related to the retrieval of novel semantic information. Results of Experiment 2 showed that novel semantic association induced a more positive late positive component (650~900 ms after the onset of target words) over the right temporal sites and right frontal sites, which might reflect the retrieval as well as selection and integration of novel semantic information respectively. In summary, the current results support the right hemispheric dominance in forming novel semantic associations, and indicate that its timing may be at the late period of processing.

Key words: novel semantic association, creative thinking, Chinese two-part allegorical sayings, Right hemispheric dominance, late positive component