The Development Of The Chinese Olfactory And Gustatory Metaphor Database (COGMED) And The Neural Mechanisms Of Chinese Olfactory Metaphor Processing

Metaphor has emerged as a valuable tool for investigating abstract concepts in cognitive research.By examining Chinese olfactory and gustatory metaphors,we can gain insights into these abstract concepts and enhance our understanding of the neural mechanisms underlying metaphor.Hence,our objective is to create a standardized Chinese olfactory and gustatory metaphor database(COGMED)and investigate the neural processing of Chinese olfactory metaphors.During the development of COGMED,we recruited 200 university students from Southern Medical University to evaluate the corpus.The participants were asked to rate the corpus on seven dimensions using a 5-point scale:familiarity,meaningfulness,figurativeness,valence,difficulty,imageability,and naturalness.We conducted reliability and correlation analyses on the scores obtained for each dimension of the corpus.In the study on the neural mechanism of Chinese olfactory metaphor processing,we recruited 27 college students from East China Normal University.Functional magnetic resonance imaging(fMRI)data was collected while participants completed a metaphorical understanding task.We conducted various analyses including whole brain analysis,region of interest(ROI)analysis,generalized psychophysiological interaction analysis(gPPI),and correlation analysis between signal activity in brain regions of interest and mental image ability.The reliability and correlation analyses of the seven dimensions revealed the following:(1)The olfactory and gustatory metaphor corpus exhibited relatively high reliability coefficients,with most dimensions above 0.9 and the lowest at 0.61.(2)The dimensions of the olfactory and gustatory metaphor corpus showed similar correlations,with strong positive correlations observed among the dimensions of familiarity,meaningfulness,difficulty,imaginability,and naturalness(P<0.0001 for any two dimensions).The fMRI data analysis yielded the following results:(1)The left posterior orbitofrontal cortex showed significant activation during the processing of olfactory literal meaning,as indicated by ROI and whole brain analyses.(2)ROI analysis revealed activation in the left amygdala and left superior temporal gyrus during the processing of olfactory metaphors.(3)gPPI analysis indicated enhanced functional connections between the triangle of the left inferior frontal gyrus and the left insula,left putamen,and paracingulate gyrus during the processing of olfactory metaphors.(4)Correlation analysis demonstrated a significant positive correlation(r=0.554,P=0.003)between signal activity in the superior temporal gyrus,associated with language processing,and scores on the mental image questionnaire.This study developed a Chinese olfactory and gustatory metaphor database and investigated the neural mechanism of Chinese olfactory metaphor processing.The conclusions are as follows:(1)The COGMED tool is reliable,and inter-dimension score correlation analysis supports psycholinguistic dimension research.(2)The activation of the left orbitofrontal cortex during the processing of olfactory literal meaning suggests that people understand olfactory words through olfactory perception.(3)During the processing of olfactory metaphors,there is increased interaction between brain regions responsible for metaphor processing and those involved in emotion and cognition.This suggests that metaphor processing may evoke heightened emotions and require greater cognitive resources.(4)The superior temporal gyrus responsible for figurative language is positively correlated with mental image ability,and the better the imagination ability,the better the metaphor.