fMRI evidence for the automatic phonological activation of briefly presented words

Functional magnetic resonance imaging was used to investigate whether people generate the phonology of briefly presented words that they do not attend. This was done in Chinese by examining the effect of orthography-phonology regularity (i.e., how predictable the phonology of a word is from its components rather than whole-word form) with high- and low-frequency words, and by using a task that diverted participants' attention to a mask, rather than the words. The results showed that there was a significant interaction between regularity and word frequency in blood oxygen level-dependent (BOLD) signal, which mirrored the pattern found in behavioral data. Specifically, for low-frequency characters, bilateral fusiform gyri, the posterior superior temporal gyrus, and inferior parietal regions were more active when using irregular compared to regular characters. There were no significant differences when high-frequency characters were used. These results support the possibility that at least for low-frequency words, phonology is automatically generated when reading, even when people do not attend to the words and even in a language where the orthography-phonology mapping is extremely irregular.