Abstract
Abstraction bridges the perception and cognition, minimizing the storage of information, while speeding up processing. In our previous study (Kuo, Shyi, & Chen, 2017, VSS), we found behavioral evidence suggesting that people applied the abstraction strategy of image-label-conversion (ILC) when they were asked to judge others’ facial expressions. Some neuroimaging studies have revealed brain regions related to labeling, and others have demonstrated areas underneath the processing of facial expression. However, cortical representations underlying facial expression labeling have not been probed directly. In the present study, we compared cortical activations in three conditions, including BaseFace, BaseLabel, and BaseFace, to investigate the brain regions that are involved in the process of ILC. In the BaseFace condition, participants were to match facial expressions from the same identity. In the BaseLabel condition, they had to choose between a pair of affective labels the one that matches a previously displayed facial expression, which presumably would prompt them to apply the ILC strategy. Finally, in the FaceCue condition, participants were to match two faces of different identities but exhibiting the same expression, which may adopt the ILC twice. The contrasts of brain activation between the three conditions showed that the right ventral lateral prefrontal cortex (rVLPFC), left fusiform gyrus, dorsal lateral prefrontal cortex (DLPFC), and anterior cingulate cortex (ACC) were significantly activated when participants applied the ILC. Moreover, the ROI analyses showed that (a) the rVLPFC was negatively correlated with the accuracy under the conditions where the ILC was used, (b) the rDLPFC was negatively correlated with the accuracy of BaseLabel condition under the contrast of BaseLabel > BaseFace, and (c) the activation of lFFG negatively predicted the performance of both the FaceCue and the BaseLabel conditions. Taken together, these findings highlight a network of cortical representations that may underpin the emotional abstraction of facial expressions.