Di#erence between native English and native Japanese readers in the use of visual and phonological codes in processing phonograms Rika MIZUNO and Takao MATSUI (Chubu University) Francis S. BELLEZZA (Ohio University)The aim of this study is to explore di#erences in the use that native English and native Japanese readers make of visual and phonological codes in processing phonograms. In Experiment 1, the authors conducted, both in the US and in Japan, the letter-matching experiments of Posner, Boies, Eichelman, and Taylor (1969) after modifying several problematic aspects with the procedures. In contrast to their earlier experimental results, our results showed that reaction time (RT) for letters with a physical match did not increase as a function of the inter-stimulus interval (ISI) and that mean RT in the physical match condition was shorter than that in the name match condition in Japan, although they were similar in magnitude in the US. These findings suggest that, for letters with a physical match, Japanese readers use visual codes while English readers use phonological codes. Experiment 2 employed an irregular letter-matching task devised to inhibit the use of the phonological code. The results showed that the mean RT in the physical match condition was shorter than that in Experiment 1 for English readers, although no such tendency was observed for Japanese readers, indicating that English readers largely depend on phonological codes while Japanese readers depend on visual codes in processing phonograms.

Lexical decision times for homophones are usually longer than are those for nonhomophones, a phenomenon known as the homophone e ect. However, experimental results regarding lexical decision times for Japanese homophones with multiple mates were inconsistent. We considered that this inconsistency could be due to the variance in the phonological familiarity regarding the homophones. Accordingly, we measured the lexical decision times for Japanese homophones with multiple mates and for those with a single mate by controlling their phonological familiarity. e results showed that homophone e ects were found for both, but the e ects for the single-mate homophones were smaller than were those for the multiple-mate homophones. Further analysis revealed that homophone e ects for multiple-mate homophones were found even when the presented homophones were the most frequent mates, unlike the ndings for English homophones. ese results suggest that both phonological familiarity and the number of mates of homophones in uence lexical decision times in native Japanese readers, and further, that in the case of multiple-mate homophones, multiple mates are activated irrespective of their frequency, which prolongs lexical decision times.

In our previous letter-matching experiments with native English and Japanese readers employing phonograms as stimuli, physical-matching reaction times (RTs) for Japanese readers were the shortest. We hypothesized that the heavy reliance of Japanese readers on visual codes in processing Kanji dominant texts extends to the processing of phonograms, which leads to short visual encoding times. However, all matching RTs at shorter inter-stimulus intervals (ISIs) were prolonged due to some factor other than encoding, making it impossible to determine encoding times based on matching RTs. Assuming this factor to be the time required for attention switching, we measured simple RTs in order to determine attention-switching times in addition to matching RTs in two letter-matching experiments that manipulated the stimulus onset asynchrony (SOA) by varying first letter presentation times for alphabetic and Japanese phonograms with English and Japanese readers. Simple RTs were found to be longer at shorter SOAs, which is consistent with our assumption. Net matching RTs calculated by eliminating the time required for attention switching indicated that both visual and phonological encodings by native English readers were completed between 100 ms and 300 ms. In contrast, in native Japanese readers, visual encoding was completed within 100 ms, while phonological encoding required the same amount of time as native English readers, which supports our hypothesis.

Rika Mizuno and Takao Matsui （Chubu University）Homophone effects, which refer to the phenomenon in which lexical decision times are longer for homophones than nonhomophones, have not been consistently observed for Japanese homophones with multiple mates. Mizuno and Matsui (2016) explored this inconsistency, finding that phonological familiarity of homophones-namely, the total frequencies of a homophone and all of its mates-can countervail homophone effects. However, it remains unclear why phonological familiarity has such a great influence on homophone processing by native Japanese readers, who rely very little on phonological information when processing words (Mizuno & Matsui, 2013). We hypothesized that high phonological familiarity influences lexical decision. Accordingly, we conducted lexical decision and semantic categorization experiments using Japanese homophones with high and low phonological familiarity. The results revealed that high phonological familiarity decreased lexical decision time, but not semantic categorization time, indicating that lexical decision tasks are sensitive to the phonological familiarity of stimulus words. Finally, we discuss the need to control the phonological familiarity of homophones in some way in the context of lexical decision tasks.

Native Japanese readers are known to rely heavily on visual codes and far less on phonological codes in letter processing (Mizuno, Matsui, & Bellezza, 2007). This study aimed to determine whether the lexical access of words written in kanji characters would parallel Japanese letter processing. Two experiments measured native Japanese readers' performance on lexical decision tasks under three nonword conditions: orthographically misleading transposed-letter nonwords, phonologically misleading pseudohomophones, and standard nonwords. The results showed that readers' performance was impaired by transposed-letter nonwords but not by pseudohomophones, suggesting that native Japanese speakers relied heavily on visual information and to a lesser degree on phonological information in the lexical access of kanji words. These characteristics of lexical access in native Japanese readers may be adaptations to the fact that Japanese kanji words have many homophones.