TY - JOUR
T1 - Differential roles of spatial frequency on reading processes for ideograms and phonograms
T2 - A high-density ERP study
AU - Horie, Shizuka
AU - Yamasaki, Takao
AU - Okamoto, Tsuyoshi
AU - Nakashima, Taisuke
AU - Ogata, Katsuya
AU - Tobimatsu, Shozo
N1 - Funding Information:
This work was supported in part by Grants-in-Aid for Scientists, No. 18659259 (to S.T.) and No. 20591026 (to T.Y.), from the Ministry of Education, Culture, Sports, Science and Technology of Japan . We would like to thank Ms. Ikue Ijichi and Ms. Yuka Miyanaga for their technical contributions.
PY - 2012/1
Y1 - 2012/1
N2 - The neural substrate of the dissociation between reading Japanese ideograms (Kanji) and phonograms (Kana) is currently unclear. To test whether spatial frequency (SF) information is responsible for this phenomenon, we recorded high-density event-related potentials (ERPs) with unfiltered or spatially filtered word stimuli in Japanese-speaking subjects. Kanji (early-learned, late-learned), Kana (word, non-word), and scrambled characters served as stimuli. Fourier analysis revealed that Kanji and Kana were characterized by high-SF (HSF) and low-SF (LSF) information, respectively. In ERPs with unfiltered stimuli, bilateral occipital P100, left occipitotemporal N170 and fronto-central N400 were elicited. Scrambled characters did not evoke left-lateralized N170 or clear N400. Under the LSF condition, P100 and N170 latencies for Kanji were significantly longer than those for Kana. In the HSF condition, P100 and N170 latencies for late-learned Kanji were significantly longer than those for early-learned Kanji. There was no significant difference in the N400 between Kanji and Kana in both SF conditions. These results suggest that early visual responses, but not the semantic component, are influenced by SF. This indicates a close link between Kana and LSF information, and between Kanji and HSF information. The differential effects of SF could underlie the neural basis of the differences between Kanji and Kana reading.
AB - The neural substrate of the dissociation between reading Japanese ideograms (Kanji) and phonograms (Kana) is currently unclear. To test whether spatial frequency (SF) information is responsible for this phenomenon, we recorded high-density event-related potentials (ERPs) with unfiltered or spatially filtered word stimuli in Japanese-speaking subjects. Kanji (early-learned, late-learned), Kana (word, non-word), and scrambled characters served as stimuli. Fourier analysis revealed that Kanji and Kana were characterized by high-SF (HSF) and low-SF (LSF) information, respectively. In ERPs with unfiltered stimuli, bilateral occipital P100, left occipitotemporal N170 and fronto-central N400 were elicited. Scrambled characters did not evoke left-lateralized N170 or clear N400. Under the LSF condition, P100 and N170 latencies for Kanji were significantly longer than those for Kana. In the HSF condition, P100 and N170 latencies for late-learned Kanji were significantly longer than those for early-learned Kanji. There was no significant difference in the N400 between Kanji and Kana in both SF conditions. These results suggest that early visual responses, but not the semantic component, are influenced by SF. This indicates a close link between Kana and LSF information, and between Kanji and HSF information. The differential effects of SF could underlie the neural basis of the differences between Kanji and Kana reading.
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U2 - 10.1016/j.neures.2011.10.003
DO - 10.1016/j.neures.2011.10.003
M3 - Article
C2 - 22020307
AN - SCOPUS:83155192126
SN - 0168-0102
VL - 72
SP - 68
EP - 78
JO - Neuroscience Research
JF - Neuroscience Research
IS - 1
ER -