Subliminal convergence of Kanji and Kana words: further evidence for functional parcellation of the posterior temporal cortex in visual word perception.
Recent evidence has suggested that the human occipitotemporal region comprises several subregions, each sensitive to a distinct processing level of visual words. To further explore the functional architecture of visual word recognition, we employed a subliminal priming method with functional magnetic resonance imaging (fMRI) during semantic judgments of words presented in two different Japanese scripts, Kanji and Kana. Each target word was preceded by a subliminal presentation of either the same or a different word, and in the same or a different script. Behaviorally, word repetition produced significant priming regardless of whether the words were presented in the same or different script. At the neural level, this cross-script priming was associated with repetition suppression in the left inferior temporal cortex anterior and dorsal to the visual word form area hypothesized for alphabetical writing systems, suggesting that cross-script convergence occurred at a semantic level. fMRI also evidenced a shared visual occipito-temporal activation for words in the two scripts, with slightly more mesial and right-predominant activation for Kanji and with greater occipital activation for Kana. These results thus allow us to separate script-specific and script-independent regions in the posterior temporal lobe, while demonstrating that both can be activated subliminally.
Nakamura
Kimihiro
K
EHESS/CNRS/ENS, Paris, France. kimihiro@m.u-tokyo.ac.jp
Dehaene
Stanislas
S
Jobert
Antoinette
A
Le Bihan
Denis
D
Kouider
Sid
S
D000328:Adult; D001931:Brain Mapping; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D011930:Reaction Time / Q000502:physiology; D011932:Reading; D012016:Reference Values; D013360:Subliminal Stimulation; D013702:Temporal Lobe / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*