Encoding times for phonograms in English and Japanese readers: Eliminating the time for attention switching

Abstract

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.