Neural substrates of semantic relationships: common and distinct left-frontal activities for generation of synonyms vs. antonyms.
Synonymous and antonymous relationships among words may reflect the organization and/or processing in the mental lexicon and its implementation in the brain. In this study, functional magnetic resonance imaging (fMRI) is employed to compare brain activities during generation of synonyms (SYN) and antonyms (ANT) prompted by the same words. Both SYN and ANT, when compared with reading nonwords (NW), activated a region in the left middle frontal gyrus (BA 46). Neighboring this region, there was a dissociation observed in that the ANT activation extended more anteriorly and laterally to the SYN activation. The activations in the left middle frontal gyrus may be related to mental processes that are shared in the SYN and ANT generations, such as engaging semantically related parts of mental lexicon for the word search, whereas the distinct activations unique for either SYN or ANT generation may reflect the additional component of antonym retrieval, namely, reversing the polarity of semantic relationship in one crucial dimension. These findings suggest that specific components in the semantic processing, such as the polarity reversal for antonym generation and the similarity assessment for synonyms, are separately and systematically laid out in the left-frontal cortex.
Jeon
Hyeon-Ae
HA
Neuroscience Research Institute, Gachon University of Medicine and Science, 1198 Kuwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea.
Lee
Kyoung-Min
KM
Kim
Young-Bo
YB
Cho
Zang-Hee
ZH
D000328:Adult; D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D007839:Functional Laterality; D006801:Humans; D007807:Language Tests; D008037:Linguistics; D008279:Magnetic Resonance Imaging; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D011932:Reading; D013647:Task Performance and Analysis; D055815:Young Adult