The Proximate Phonological Unit of Chinese-English
Bilinguals: Proficiency Matters
Rinus Gerardus Verdonschot1,2*, Mariko Nakayama3, Qingfang Zhang4, Katsuo Tamaoka1,
Niels Olaf Schiller2
1 Graduate School of Languages and Cultures, Nagoya University, Nagoya, Japan, 2 Leiden Institute for Brain and Cognition, Leiden University Centre for Linguistics &Cognitive Psychology Unit, Leiden University, Leiden, The Netherlands, 3 Faculty of Letters, Arts and Sciences, Waseda University, Tokyo, Japan, 4 Key Laboratory of
Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, PR China

Abstract
An essential step to create phonology according to the language production model by Levelt, Roelofs and Meyer is toassemble phonemes into a metrical frame. However, recently, it has been proposed that different languages may rely on
different grain sizes of phonological units to construct phonology. For instance, it has been proposed that, instead ofphonemes, Mandarin Chinese uses syllables and Japanese uses moras to fill the metrical frame. In this study, we used amasked priming-naming task to investigate how bilinguals assemble their phonology for each language when the two
languages differ in grain size. Highly proficient Mandarin Chinese-English bilinguals showed a significant masked onset
priming effect in English (L2), and a significant masked syllabic priming effect in Mandarin Chinese (L1). These results
suggest that their proximate unit is phonemic in L2 (English), and that bilinguals may use different phonological units
depending on the language that is being processed. Additionally, under some conditions, a significant sub-syllabic priming
effect was observed even in Mandarin Chinese, which indicates that L2 phonology exerts influences on L1 target processing
as a consequence of having a good command of English.
Citation: Verdonschot RG, Nakayama M, Zhang Q, Tamaoka K, Schiller NO (2013) The Proximate Phonological Unit of Chinese-English Bilinguals: Proficiency
Matters. PLoS ONE 8(4): e61454. doi:10.1371/journal.pone.0061454
Editor: Kevin Paterson, University of Leicester, United Kingdom
Received January 14, 2013; Accepted March 9, 2013; Published April 30, 2013
Copyright: ß 2013 Verdonschot, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Rinus Verdonschot's research is presently supported by a Japanese Society for the Promotion of Science (JSPS) post-doctoral fellowship for foreign
researchers (P12315). This research project was also supported by the Royal Netherlands Academy of Arts and Sciences (KNAW) and the Chinese Academy of
Sciences (CAS) through a China Exchange Program grant (11CPD002). The funders had no role in study design, data collection and analysis, decision to publish, or
preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.
* E-mail: rinusverdonschot@gmail.com

model [1]. In the same way, masked priming research [4,7,9] has
shown that when a prime is presented briefly (50 ms) immediately
before a to-be-named target (e.g. pear), naming latencies are
significantly faster when the prime-target pairs share the onset (e.g.
pole-PEAR) than when the prime-target pairs do not share the onset(e.g., take-PEAR).
However, these results were all obtained with Indo-European
languages such as Dutch and English. In fact, several previous
studies indicate that the size of the unit to fill the metrical frames
may be divergent across languages. For instance, Chen, Chen andDell [10] and, more recently, O'Seaghdha, Chen and Chen [11]pointed out that a language such as Mandarin Chinese has very
different phonological properties from Dutch and English. For
instance, Mandarin has a limited inventory of syllables; syllables
have a very simple structure and re-syllabification is absent. In
several implicit priming experiments, Chen et al. [10] andO'Seaghdha et al. [11] reliably showed syllabic priming effects,
but did not find onset-priming effects with monolingual Mandarin
Chinese speakers (see also Wong, Huang, and Chen [12] who,
although observing word-initial body priming in Cantonese
Chinese, did not obtain significant onset priming effects for
Cantonese either). Similarly, in Japanese, a profoundly morabased language (usually comprising of a CV or V, e.g. /ka/ or /a/,a nasal coda, /N/, or a geminate /Q/, but never a single consonant,e.g /k/), Kureta, Fushimi, and Tatsumi [13] using the implicit

Introduction
Speaking involves the retrieval of phonological representations
and their conversion into articulatory commands. According to thelanguage production model by Levelt, Roelofs and Meyer [1], anessential step in this process is the insertion of phonemes into syllabic
metrical frames (called segment-to-frame association). One of the
motivations for the construction of syllables in this way comes fromfrequent re-syllabification found in Dutch and English [1], which
necessitates an on-the-fly construction rather than the storage ofsyllables. The motivation that this process takes places in units ofphonemes comes from results of implicit priming experiments [2,3]as well as priming experiments [4±8]. The implicit priming
paradigm first teaches associations to certain prompt words (e.g.
prompt: single ± response: loner). When participants are subsequently prompted (e.g. single), they should verbally produce thelearned association (e.g. loner). By manipulating the responses tothe prompts one can create homogenous groups (loner, local, lotus)
or heterogeneous groups (loner, bread, car). It has been shown thatwhen the onset (phoneme or more) overlaps significant facilitation
effects occur but not when only the ending overlaps (e.g. murder,
wonder, boulder). It has been shown that significant facilitation effects
occur for homogeneous groups but not for heterogeneous groups.
These results were taken to indicate the incremental nature andunit size of the association-to-frame process in the Levelt et al.
PLOS ONE | www.plosone.org

1

April 2013 | Volume 8 | Issue 4 | e61454

The Proximate Unit of Chinese-English Bilinguals

per million (taken from the English Lexicon Project [19]), length
was 5.160.9 letters and syllable length was 1.560.5 syllables. The
following priming conditions were created: Identity (prime andtarget are identical), Onset Overlap ± primes had a single
phoneme overlap with the target ± vs. their Onset Control (e.g.
target BENCH, primes: bark vs. dark), CV Overlap ± primes had
onset+vowel overlap with the target ± vs. their CV Control (e.g.
target BENCH, primes: bell vs. cell). There was no statisticaldifference between the four prime types, i.e. Onset Overlap, Onset
Control, CV Overlap, CV Control in terms of frequency (F,1)
and length (F,1; all groups had one syllable), and when Identity(prime = target) was included in the comparison, there was again
no difference in frequency (F,1), but there was a difference
between identity and the other primes in terms of length, F(4) = 48.4, p,.001, and syllables, F(4) = 45.1, p,.001, with theidentity being 1.4 phoneme longer and having half a syllable extra
compared to the other groups. See Table 1 for stimulus properties
and Appendix S1 for an overview.
Chinese Experiment. Twenty-four target words were selected; half of them adhered to a CV (e.g. /ba/) and the other half
to a CVN (e.g. /ban/) structure, average log frequency was
5.061.5, taken from [20] and strokes were on average 8.063.1.
Primes were selected to match syllabic structure, that is: Same
Syllabic Structure (i.e. CV-CV or CVN-CVN) or Different
Syllabic Structure (i.e. CVN-CV or CV-CVN) and the amountof overlap (Onset, CV/CVN and Control). Stimuli were
controlled for log frequency (Onset Overlap = 4.462.1, CV/
CVN Overlap = 4.462.0, Control = 4.861.7, F,1), strokes (Onset Overlap = 10.063.2, CV/CVN Overlap = 10.463.8, Control = 9.663.5, F,1). We also made sure to avoid characters withmultiple pronunciations and/or semantic or radical overlap, see
Appendix S2 for an overview.

priming paradigm, and Verdonschot et al. [14] using the masked
priming paradigm, were unable to observe onset priming effects. In
these studies, significant priming was obtained only when the mora
overlapped within a homogenous group, or between prime-target.
To preserve the way in which phonological encoding is defined in
the Levelt et al. model [1] but still being able to account for crosslinguistic differences, O' Seaghdha and Chen [15] and O'Seaghdha
et al. [11] coined the term proximate unit as a unit differing in grain size
between languages, which is used to fill the metrical frame. In
Dutch/English this would be the phoneme, in Mandarin
Chinese the syllable (but see [12,16,17] who assume a role forsub-syllabic constituents in Cantonese Chinese) and in Japanesethe mora [13,14].
This paper is concerned with a consequence of the proximate
unit principle. Specifically, we are interested in the situation whena person speaks more than one language, particularly in the case when
the unit is proposed to differ such as between Mandarin Chineseand English. More specifically, we would like to explore whether
the production system can distinguish and/or adjust the grain size
depending on the language used and whether the unit size of one
language influences that of the other language.
In order to investigate this, we recruited native Chinese students
who were highly proficient in English and spoke Mandarin
Chinese (hereafter called Chinese) as their L1. Using the masked
priming paradigm, we investigated what the proximate unit wasfor each of their languages and whether an influence of language
regarding the unit-to-frame association process could be found. If
the production system mainly uses a Chinese-based (L1) proximate
unit irrespective of target languages, no onset priming will beobserved when bilinguals are engaged in the task in English (L2). If
the production system has discrete proximate units between
Chinese and English, then the bilinguals would show syllable but
not onset priming in Chinese, while showing onset priming in
English. Lastly, if proficiency in English influences Chinese word
production, we may expect onset priming even in Chinese.

DesignEnglish Experiment. The design adopted a 5 (Repetition: 1,
2, 3, 4, 5)65 (Prime Type: Identity, Onset Overlap, Onset
Control, CV Overlap, CV Control) within participants design.
Chinese Experiment. The experiment adopted a 2 (Syllabic
Structure: Same, Different)63 (Overlap: Onset, CV/CVN,
Control) within-participants design. For instance, the target k /ba1/ `eight' was preceded by 1) a same structure onset overlap
prime, e.g. < /bi1/ `to force', 2) a same structure CV/CVN
overlap prime, e.g. ô /ba1/ `desire', 3) a same structure control
prime, e.g. ´ /pa1/ `lean, bend over', 4) a different structure
onset overlap prime, e.g. ¾ /bin1/ `guest', 5) a different structure
CV/CVN overlap prime, e.g. í /ban1/ `class', and lastly 6) adifferent structure control prime, e.g.
/pan1/ `climb'.

MethodParticipants

Twenty Chinese native participants (attending various universities in the Beijing area, China, 12 female, age 24.262.9 years)
were recruited to take part in this experiment. Participantsreceived 50 RMB (<8 US $) compensation. The current study wasapproved by the ethics committee of the Institute of Psychology,
Chinese Academy of Sciences (Beijing). Written consent was
obtained from participants before the experiment started. Half ofthe participants passed the Test for English Majors at the highest
level (TEM-8). The rest passed either the College English Test
(CET-6) or the TOEFL/IELTS exams. Participants reported tohave started to come in contact with English around 11.362.5
years of age. Active English ability (speaking/writing) self-reportwas 6.861.2 on a 1±10 scale and passive ability (reading/listening)
was self-reported to be 7.661.0. Average high-school grade was
8.161.4 on a 1±10 scale and participants reported that theiramount of speaking, reading and listening (in hours) per day on
average was: 0.4 h60.3, 1.9 h61.4 and 1.0 h60.8 respectively,
also they obtained a very high total (48476342; score range 0±5000) on the Swansea English vocabulary test we administeredafter the experiment (for more details see Meara [18]). All
participants had normal or corrected-to-normal vision.

Table 1. Properties of English Prime Words (examples are forthe target: BENCH).

Prime Type

StimuliEnglish Experiment. Forty-two target words were selected(half mono-, half bi-syllabic). The log KF frequency was 9.661.2
PLOS ONE | www.plosone.org

Log Frequency(SD)

Length(SD)

Syllables(SD)

Identity (bench)

9.6 (1.2)

5.1 (0.9)

1.5 (0.5)

Onset Overlap (bark)9.9 (1.3)

3.6 (0.5)

1 (0)Onset Control (dark)

9.5 (1.3)

3.6 (0.5)

1 (0)CV Overlap (bell)

9.5 (1.4)

3.8 (0.4)

1 (0)CV Control (cell)

9.6 (1.2)

3.8 (0.4)

1 (0)Note: Target properties are identical to Identity Prime.
doi:10.1371/journal.pone.0061454.t001

2

April 2013 | Volume 8 | Issue 4 | e61454

The Proximate Unit of Chinese-English Bilinguals

To avoid excessive repetitions, prime-target combinations
were distributed over participants in a Latin-square design suchthat each participant named each target only three times(instead of six; i.e. 72 trials overall per participant) though still
having encountered all prime types/conditions equally often.
Each target occurrence was set in one block, resulting in threeblocks in total (with short breaks of 30 seconds between eachblock and warm-up of three items per block). The order oftarget words within a block and the block order itself wererandomized for each participant.

F2(4, 156) = 31.4, MSe = 3714.7, p,.001; Min F9 (4, 218) = 17.4,
p,.001. Importantly, there was no interaction between Repetition and Prime Type, both Fs,1. Planned comparisons
showed that targets were named significantly faster in the
Identity condition (bench ± BENCH) than any of the otherprime type conditions (all ps,.001). Furthermore, When theonset overlapped (i.e., bark - BENCH), there was a 22 ms
significant facilitation effect, t1(19) = 3.7, SD = 27.0, p,.001;
t2(41) = 4.1, SD = 36.8, p,.001, Min F9 (1, 48) = 7.5, p,.01,
compared to its control. In addition, when the CV overlapped (i.
e., bell ± BENCH), there was a 31 ms facilitation effect,t1(19) = 5.8, SD = 23.8, p,.001; t2(41) = 4.7, SD = 40.6, p,.001,
Min F9 (1, 58) = 13.3, p,.001, compared to its control. The 7 ms
difference between Onset- and CV Overlap was not significant,t1(19) = 1.3, SD = 21.9, p = .194; t2(41) = 1.3, SD = 31.7, p = .186,
Min F9 (1, 52) = .85, p = .362, indicating that the facilitation
effects are mainly due to the initial phoneme overlap (see also
Kinoshita, 2000). The error rates did not reveal a significant
effect of Prime Type condition (Fs,1) and were therefore notfurther analyzed.

Procedure

The experiment was performed using E-Prime 2 Professional
Software (Psychology Software Tools). Participants were seated ina quiet room approximately 70 cm from a 21 inch CRT computer
screen with a refresh rate of 100 Hz. Naming latencies were
measured from target onset using a voice-key, connected with thecomputer via a PST Serial Response Box.
Each trial involved the following sequence: a fixation cross (+)
was presented at the center of the screen for 1,000 ms, followed bya forward mask (##) for 500 ms, subsequently the prime waspresented for 50 ms, followed by the target word which
disappeared after 2 seconds or when participants made a vocal
response. Primes, masks and targets were presented in 28-point
boldfaced Song or Courier New font. The visual angles of thetarget words were less than 2 degrees both horizontally andvertically. Participants were asked to name the word aloud asquickly and accurately as possible. Following each response, theexperimenter judged whether the response was correct or not (orwhether a voice key error had occurred). Both experiments took
less than 10 minutes each.

Chinese Experiment

In total, 7.2% percent of the data were discarded, 0.6% due toerrors (e.g. non-correct target naming) additionally voice-key
errors (e.g. disfluencies, accidental triggering) and outliers (set to 2
SD of a participant's mean per condition) amounted to 6.6% of
the data being discarded, see Table 3 for results. There was no
main effect of Syllabic Structure (same, different), both Fs,1.
There was a main effect of Prime Type (onset, CV/CVN, control),F1(2, 38) = 14.0, MSe = 301.7, p,.001, F2(2, 46) = 3.1,
MSe = 1854.2, p = .05, min F9(2, 65) = 2.54, p = .09, and there wasan interaction between Syllabic Structure and Prime Type in thesubjects, F1(2, 38) = 5.3, MSe = 213.5, p,.01, but not the items
analysis, F2,1. Planned comparisons showed that there wassignificant priming for the Onset condition when the syllabic
structure overlapped, t1(19) = 5.2, SD = 22.7, p,.001; t2(23) = 2.5,
SD = 50.0, p,.05, min F9(1, 33) = 5.1, p,.05; and also for the CV/
CVN, t1(19) = 5.3, SD = 23.0, p,.001; t2(23) = 2.7, SD = 48.1,
p,.05, min F9(1, 34) = 5.8, p,.05. However, these effects were
not consistent when the syllabic structure did not overlap, onset
prime vs. control, t1(19) = 2.1, SD = 19.8, p,.05; t2(23) = 1.2,
SD = 53.7, p = .25, min F9(1, 36) = 1.1, p = .30 and CV prime vs.
control, t1(19) = 1.7, SD = 21.2, p = .11, t2(23) = 1.0, SD = 54.7,
p = .30, min F9(1, 36) = .74, p = .39. The error rates were low and

Results
English Experiment

In total, ten percent of the data were discarded comprisingtarget words which were incorrectly pronounced (coded byexperimenter during the experiment) and/or target words
which were unfamiliar to the participant (assessed by a posttest questionnaire) totaling 4.9%. Furthermore, voice-key
errors (e.g. disfluencies, accidental triggering) and outliers (setto 2 SD of a participant's mean per condition per repetition)amounted to 5.1% of the data being discarded, see Table 2 forresults.
There was a main effect of Repetition, indicating that subjects
responded faster with increasing repetitions, F1(4, 76) = 57.1,
MSe = 6198.4, p,.001; F2(4, 156) = 106.7, MSe = 6999.6,
p,.001; Min F9 (4, 157) = 37.2, p,.001. There was a main
effect of Prime Type, F1(4, 76) = 38.8, MSe = 1573.8, p,.001;

Table 3. Results for Chinese Experiment (RT = averagereaction time; SD = standard deviation; %E = percentage
error).

Table 2. Results for the English part of the experiment(RT = average reaction time; SD = standard deviation; %E = percentage error).

Prime Type

Examples (prime - target)

RT (SD)%E

0.4

Same Syllabic Structure
Onset/bi1/ - /ba1/ or /bin1/ - /ban1/ 543 (71)

Prime Type

ExampleRT (SD)%E

CV/CVN/ba1/ - /ba1/ or /ban1/ - /ban1/ 541 (59)0.0

Identity

bench - BENCH

618 (86)

4.6

Control/pa1/ - /ba1/ or /pan1/ - /ban1/ 569 (71)0.0

Onset Overlap

bark - BENCH

653 (77)

4.9

Different Syllabic Structure

Onset Control

dark - BENCH

675 (89)

5.5

Onset

/bin1/ - /ba1/ or /bi1/ - /ban1/ 549 (72)0.8

CV Overlap

bell - BENCH

646 (83)

4.9

CV/ban1/ - /ba1/ or /ba1/ - /ban1/ 551 (68)

1.3

CV Control

cell - BENCH

677 (93)

4.6

Control/pa1/ - /ban1/ or /pan1/ - /ba1/ 559 (70)0.8

doi:10.1371/journal.pone.0061454.t002

PLOS ONE | www.plosone.org

doi:10.1371/journal.pone.0061454.t003

3

April 2013 | Volume 8 | Issue 4 | e61454

The Proximate Unit of Chinese-English Bilinguals

did not reveal a significant effect of prime type condition (Fs,1)and were therefore not further analyzed.

Note that our L1 sub-syllabic findings do not have to beincompatible with the role of the syllable as proximate unit
proposed by O'Seaghdha et al. [11]. For instance, Qu et al. [22](p. 14268) also state that syllables are the primary selectablephonological units below the word level and phonemic segments
may be retrieved via syllabic mediation. In addition, O'Seaghdha,
Chen & Chen [23] and O'Seaghdha et al. [11] indicate that theirmodel for Mandarin Chinese assumes that, although syllables are
the primary (first selected) unit for language production, importantly, phonemic specification does occur for selected syllables.
Before reaching any conclusions, two possible considerations
regarding our study should be discussed. The first one is that the
Chinese part of the experiment always followed the English
experiment. We therefore cannot rule out any spillover as a resultof experiment order. However, as this was a masked priming
study, participants were not consciously aware of the prime-target
relationship and the effect is therefore unlikely to have been
strategic. However, even if order had an effect, this does notcompromise our conclusion that the assembly of phonology inChinese can be affected by the use of English in our participants.
The second is that the English uses a script, in which
orthographic units are used that roughly correspond to phonemes,
whereas Chinese script is syllabic. The same concern was put
forward by Verdonschot et al. [14], who conducted two priming
experiments in Japanese, in which they changed the script type toromaji (alphabetic Japanese). Importantly, they essentially foundthe same results (only mora priming in Japanese) regardless of
script type. In addition, Chen and Chen [24] in two experiments
using auditory and visual implicit priming and picture naming
showed that syllabic overlap but never phonemic overlap
produced significant priming regardless whether prompts were
written, spoken or pictorial. Chen and Chen's study [24] suggestthat syllabic priming in Chinese is therefore not due to theproperties of Chinese script. Based on the results of Verdonschot etal. [14] and Chen and Chen [24], it is reasonable to assume thatthe size of the unit to fill the metrical frames is not dependent on
the properties of script per se.
In conclusion, our data showed onset priming in English forhighly proficient Chinese-English bilinguals. Clearly, their proximate unit is phonemic in nature when speaking in their L2. Ourdata also indicate that proficiency in English has an effect on theprocessing of their native language, Chinese, although thesignificant sub-syllabic priming effects were confined to situations
in which the syllabic structure of prime and target overlap (i.e.
CV-CV or CVN-CVN). Future work should investigate whether
for instance low proficient Chinese ± English bilinguals also show
onset effects in their L2/L1. Although the syllable still plays themain role in constructing Mandarin Chinese phonology[11,21,25] this study does report sub-syllabic priming for Chinese
as a consequence of having a good command of English, although
this only occurred when the syllabic structure overlaps.
Finally, we would like to advocate that future models of
language production should allow for different grain size of
Proximate Phonological Units and influences between various
languages in their account(s) of how the unit-to-frame association
process to construct phonology takes place.

Discussion
The data clearly show onset, priming for high proficientbilingual Chinese speakers in their L2 (English). Apparently, inthese bilingual speakers, the phoneme is a unit which can beprimed. This indicates that in their L2 their phonology isassembled similarly to English native speakers. If it were assembled
in an L1-Chinese (syllabic) way [10,11] sub-syllabic priming effects
would have been unlikely to emerge. Our bilinguals also showedreliable syllable priming effect in Chinese, replicating previous
studies testing monolingual Chinese speakers [21]. In addition, we
found sub-syllabic priming effects even in Mandarin Chinese, althoughthese effects were observed only when the syllabic structure of primetarget pairs overlapped.
In light of these results it is important to mention that
empirical observations by Wong and Chen [16,17] who used thepicture naming paradigm as well as Wong et al. [12] who used
implicit priming, indicated the existence of sub-syllabic priming
in Cantonese Chinese (see introduction). However, as participants in all three studies were living in Hong Kong and wererecruited from the Chinese University of Hong Kong and Hong
Kong University (all highly bilingual environments) it may havebeen possible that their L2-English proficiency was considerable(A.W. Wong, personal communication, March 5, 2013). This,according to the findings reported in the current paper, could
have had an influence on how phonological information wasprocessed in their L1 (Cantonese). Future work investigating theproximate phonological unit in Cantonese with high- and lowproficient L2-English speakers should be able to assess whether
Cantonese shows the same pattern of results as Mandarin doesor whether sub-syllabic effects appear in Cantonese regardless of
any L2 proficiency. In addition, we suggest that studies
exploring the proximate unit should investigate whether
proficiency in other languages exists for participants, even whenreporting findings for the L1.
Recently, sub-syllabic priming in Chinese has also been
investigated by Qu, Damian, and Kazanina [22] who suggest afunctional role of phonemes at the stage of phonological encodingin Mandarin Chinese. Qu et al. asked participants to name apicture including its color (for example: ``yellow box'' /huang2he2zi/) while recording participants' event related
potentials (ERPs). Yellow (/huang2/) and ``box'' (/he2zi/)
overlapped in their onset, while green box (/luÈ4he2zi/) did not.
Consistent with earlier findings by Chen et al. [10] andO'Seaghdha et al. [11], Qu et al. [22] did not observe a
behavioral difference in RTs for onset repetition but they did
observe more negative ERP amplitudes. They attributed this toa higher load for internal speech monitoring due to onset
repetition; which would cancel out onset facilitation (p. 14268).
However, on the basis of our results one may speculate whether
priming could be contingent on structure overlap in Chinese.
For instance, most of Qu et al.'s stimuli (e.g. /huang2/ and /he2/) do not share structure which might have some influence
regarding the absence of a behavioral effect. However, Chen etal. [10] (p. 779) and O'Seaghdha et al. [11] (p. 300) did use
similarly structured stimuli (e.g. CV starting with ``mo, ma, mu,mi'') and did not find onset priming as well. Our findings are
therefore most likely the result of high L2-proficiency althoughmore work is necessary to investigate why the L1 sub-syllabic
priming reported in this paper was obtained only when the
structure overlapped.
PLOS ONE | www.plosone.org

Supporting Information
Appendix S1 English Stimuli (Experiment 1).

(PDF)

Appendix S2 Chinese Stimuli (Experiment 2).

(PDF)

4

April 2013 | Volume 8 | Issue 4 | e61454

The Proximate Unit of Chinese-English Bilinguals

Acknowledgments

Author Contributions

We thank Jun Lai for her help with constructing the Chinese stimuli, Feng
Chen for his help in recruiting the participants, and Wido La Heij for hiscomments on this manuscript.

Conceived and designed the experiments: RV MN. Performed theexperiments: RV. Analyzed the data: RV. Contributed reagents/
materials/analysis tools: RV MN. Wrote the paper: RV MN QZ KT NS.

References
14. Verdonschot RG, Kiyama S, Tamaoka K, Kinoshita S, La Heij W, et al. (2011)
The functional unit of Japanese word naming: evidence from masked priming.
J Exp Psychol Learn Mem Cogn 37: 1458±1473.
15. O'Seaghdha PG, Chen JY (2009) Toward a language-general account of word
production: The proximate units principle. In N.A. . Taatgen & H. . van Rijn
(Eds.,), Proceedings of the 31st Annual Conference of the Cognitive Society (pp.
68±73). Austin, TX: Cognitive Science Society.
16. Wong AW, Chen HC (2008) Processing segmental and prosodic information in
Cantonese word production. J Exp Psychol Learn Mem Cogn 34: 1172±1190.
17. Wong AW, Chen HC (2009) What are effective phonological units in Cantonese
spoken word planning? Psychon Bull Rev 16: 888±892.
18. Meara P (2005) X_Lex: The Swansea Vocabulary Levels Test. v2.05. Swansea:
Lognostics.
19. Balota DA, Yap MJ, Cortese MJ, Hutchison KA, Kessler B, et al. (2007) The
English Lexicon Project. Behav Res Methods, 39: 445±459.
20. Chinese Linguistic Data Consortium (2003) °ãIí(Íh [Chinese
Lexicon] (CLDC-LAC-2003±01). Beijing, China: State Key Laboratory ofintelligent Technology and Systems, Tsinghua University, and Institute ofAutomation, Chinese Academy of Sciences.
21. You WP, Zhang QF, Verdonschot RG (2012) Masked syllable priming effects inword and picture naming in Chinese. PLoS ONE, 7: e46595.
22. Qu Q, Damian MF, Kazanina N (2012) Sound-sized segments are significant for
Mandarin speakers. Proc Natl Acad Sci U S A, 109: 14265±14270.
23. O'Seaghdha PG, Chen JY, Chen TM (2013) Close but not proximate: The
significance of phonological segments in speaking depends on their functional
engagement. Proc Natl Acad Sci U S A, 110: E3.
24. Chen JY, Chen TM (2013) The syllable as the proximate unit in Mandarin
Chinese word production: An intrinsic or accidental property of the production
system? Psychon Bull Rev, 20:154±162.
25. Chen JY, Lin WC, Ferrand L (2003) Masked priming of the syllable in Mandarin
Chinese speech production. Chinese Journal of Psychology 45: 107±120.

1. Levelt WJM, Roelofs A, Meyer AS (1999) A theory of lexical access in speech
production. Behav Brain Sci 22: 1±75.
2. Meyer AS (1991) The time course of phonological encoding in language
production: phonological encoding inside a syllable. J Mem Lang 30: 69±89.
3. Roelofs A (2006) The influence of spelling on phonological encoding in word
reading, object naming, and word generation. Psychon Bull Rev 13: 33±37.
4. Forster KI, Davis C (1991) The density constraint on form-priming in thenaming task: Interference effects from a masked prime. J Mem Lang, 30: 1±
25.
5. Schiller NO (1998) The Effect of Visually Masked Syllable Primes on the
Naming Latencies of Words and Pictures. J Mem Lang 39: 484±507.
6. Schiller NO (2000) Single Word Production in English: The Role of Subsyllabic
Units During Phonological Encoding. J Exp Psychol Learn Mem Cogn 26: 512±528.
7. Schiller NO (2004) The onset effect in word naming. J Mem Lang, 50, 477±490.
8. Schiller NO (2007) Phonology and orthography in reading aloud. Psychon Bull
Rev 14, 460±465.
9. Kinoshita S (2000) The left-to-right nature of the masked onset effect in naming.
Psychon Bull Rev 7: 133±141.
10. Chen JY, Chen TM, Dell GS (2002) Word-Form Encoding in Mandarin
Chinese as Assessed by the Implicit Priming Task. J Mem Lang 46: 751±
781.
11. O'Seaghdha PG, Chen JY, Chen TM (2010) Proximate units in word
production: Phonological encoding begins with syllables in Mandarin Chinese
but with segments in English. Cognition 115: 282±302.
12. Wong AWK, Huang J, Chen HC (2012). Phonological Units in Spoken Word
Production: Insights from Cantonese. PloS ONE, 7: e48776.
13. Kureta Y, Fushimi T, Tatsumi IF (2006) The functional unit of phonologicalncoding: Evidence for moraic representation in native Japanese speakers. J Exp
Psychol Learn Mem Cogn 32: 1102±1119.

PLOS ONE | www.plosone.org

5

April 2013 | Volume 8 | Issue 4 | e61454