LETTER
Reply to O’Seaghdha et al.: Primary phonological planning units in Chinese are phonemically specified Whereas O’Seaghdha et al. (1) generally agree with our argument that phoneme-sized segments are implicated in Chinese language production (2), they raise two critical points. First, they argue that our main event-related potential (ERP) finding (i.e., ERP modulation resulting from initial phoneme repetition) may reflect phonological connectivity rather than functional involvement of phonemes during speech planning. We believe, however, that our ERP effects cannot be accounted for via phonological connectivity within the proximate unit framework that is espoused by these researchers. Recall that in their framework (3), the phonological encoding stage is operationalized exclusively in terms of atonal syllables, which are indivisible units without any internal structure (ref. 3, p. 297). Phonemes are not activated until a later (“penultimate”) stage at which the tone and segmental context of an atonal syllable are specified, which directly precedes articulation of speech (which begins approximately 1,000 ms after stimulus onset in our study). Whereas the temporal location of our ERP effects (200 to 400 ms after picture onset) is highly compatible with current timing estimates of phonological encoding in Western languages (4), it is rather earlier than phonological connectivity effects could be expected. Theoretically, our findings are compatible with a model in which primary phonological planning units in Chinese are phonemically specified syllables (i.e., Chinese lexical representations accessed during phonological encoding are syllabified, phonemically specified representations). In English, primary phonological planning units are phonemes and representations accessed during phonological encoding are not syllabified. Second, to account for our behavioral null finding with Mandarin speakers, we suggested an explanation in terms of increased self-monitoring in the repeated condition, which might balance out relatively subtle priming due to segmental repetition. O’Seaghdha et al. (1) point out that “if the canceling process
E4 | PNAS | January 2, 2013 | vol. 110 | no. 1
account is correct, one would expect facilitation, rather than a null effect, in faster single-word production tasks for which monitoring is not needed.” We disagree. Self-monitoring is a central component of language production (5). In single-word production tasks, such as the form-preparation (or “implicit priming”) task, in the critical homogeneous condition, all response words within a set share the initial phoneme. Whenever a target response is prepared, it is likely that other words from the response set are also activated to some extent, and increased monitoring is required to ensure an accurate response. Hence, even in this task, monitoring-based interference might cancel out subtle segment-based facilitation arising during phonological encoding in Chinese, resulting in a null effect on response latencies (3). By contrast, for speakers of English and other Western languages, more substantial facilitation resulting from a shared initial phoneme outweighs monitoring-based interference, resulting in shorter response latencies. We acknowledge that more research is needed to test these assumptions. Most importantly, despite some disagreements, we fully concur with O’Seaghdha et al. (1) on the idea that phonemesized segments are indispensable for representing words in the long-term memory of Chinese speakers. Our ERP findings provide convincing evidence against theoretical accounts that dispose of phonemes as units for lexical representations (6). Qingqing Qu1, Markus F. Damian, and Nina Kazanina School of Experimental Psychology, University of Bristol, Bristol BS8 1TU, United Kingdom 1. O’Seaghdha PG, Chen J-Y, Chen T-M (2013) Close but not proximate: The significance of phonological segments in speaking depends on their functional engagement. Proc Natl Acad Sci USA 110:E3. 2. Qu Q, Damian MF, Kazanina N (2012) Sound-sized segments are significant for Mandarin speakers. Proc Natl Acad Sci USA 109(35):14265–14270. 3. O’Seaghdha PG, Chen J-Y, Chen T-M (2010) Proximate units in word production: Phonological encoding begins with syllables in Mandarin Chinese but with segments in English. Cognition 115(2):282–302. 4. Indefrey P, Levelt WJM (2004) The spatial and temporal signatures of word production components. Cognition 92(1-2):101–144. 5. Postma A (2000) Detection of errors during speech production: A review of speech monitoring models. Cognition 77(2):97–132. 6. Silverman D (2006) A Critical Introduction to Phonology: Of Sound, Mind, and Body (Continuum, London).
Author contributions: Q.Q., M.F.D., and N.K. wrote the paper. The authors declare no conflict of interest. 1
To whom correspondence should be addressed. E-mail:
[email protected].
www.pnas.org/cgi/doi/10.1073/pnas.1217601110
