Effects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

1

Effects of Prosody Shadowing on
Japanese EFL Learners’Processing of
Object Relative Clauses in English
NAKANISHI, Hiroshi（Seinan Gakuin University）
1. Introduction
Language comprehension involves various stages, including the perceptionof input information, lexical processing, syntactic processing, semantic
processing, contextual processing, pragmatic processing, etc. Syntactic
processing, in particular, is the most cognitively demanding for Japaneselearners of English, consuming most of their finite working memory (WM),
which prevents them from using WM capacity for retention or higher-orderprocessing, such as inference and contextual processing (Nakanishi &Yokokawa, 2011; Nakanishi, Narumi, Hashimoto & Yokokawa, 2019; Narumi,
Hashimoto, Nakanishi & Yokokawa, 2018).
For Japanese learners of English, comprehension of sentences containing
an object relative clause (e.g., “The lawyer that the banker irritated filed ahefty lawsuit”) was significantly lower (Sakakibara & Yokokawa, 2015) andprocessing time was significantly longer (Hashimoto, 2011) than for a subject
relative clause (e.g., “The lawyer that irritated the banker filed a hefty
lawsuit”), indicating a higher cognitive load in the processing of the object
relative clause (Sakakibara & Yokokawa, 2016; Yokokawa, Sadato & Yoshida,2014). To understand the object relative clause, the reader must retain thehead-noun phrase (e.g., “the lawyer”) in the WM until it is integrated with therelative verb (e.g., “irritated”) in the object relative clause. As noted inprevious research, the distance between the noun and relative verb isgreater in an object relative clause than in a subject relative clause (Gibson,
1998; Grodner & Gibson, 2005). This distance is one of the reasons why
processing the object relative clause consumes considerable WM resources

2

NAKANISHI, Hiroshi

compared to the subject relative clause.
The purpose of this study is to explore whether the low automatization ofsyntactic processing in Japanese learners of English can be resolved byrepeated English shadowing. This study deals specifically with sentences
containing object relative clauses.
English shadowing is a learning method in which learners immediately
repeat the model speech presented. Previous behavioral and brain science
experiments have confirmed that the rehearsal process of phonological loops
is activated and made more efficient in the WM (Kadota, Kawasaki &Nakanishi, 2015; Kadota, Kawasaki, Shiki, Hase, Nakano, Noro, Nakanishi &Kazai, 2015). Shadowing sentences containing specific syntactic structures
may contribute to accelerated automatization of syntactic processing, inaddition to the effects on the phonetic aspect pointed out. The reason is thatpeople tend to produce sentences that contain the syntactic structure they
processed immediately before, i.e., the syntactic priming effect (Kadota, 2015).
As an example of this effect, Bock (1986) indicated that participants tend toreproduce a Prepositional-Object (PO) construction immediately after a PO
sentence was visually presented (e.g., “The rock star sold some cocaine to anundercover agent”). On the other hand, they tended to reproduce a double
object (DO) construction immediately after a DO sentence was visuallypresented (e.g., “The rock star sold an undercover agent some cocaine"). Thissyntactic priming effect has been confirmed in L1 studies (Bock, 1986;
Pickering & Branigan, 1998) and in L2 studies (Morishita, Satoi & Yokokawa,
2010). It has also been established that the greater the frequency of exposure
to a certain structure, the greater the effect (Morishita & Yokokawa, 2011).
Furthermore, Sakakibara and Yokokawa (2015) have shown that having
Japanese EFL learners repeatedly read cognitively demanding structures
facilitates their comprehension of the target structure. They trained theexperimental group by visually presenting a total of 80 English sentenceswith subject and object relative clauses followed by comprehension questions(e.g., “The rock concert was held in an outdoor stadium. The guitarist that
Beth liked began to play a hit song. Q: The guitarist liked Beth”). The control
group was also visually presented with 80 total English sentences followedby comprehension questions (e.g., “During the meal, Tom was unable toconcentrate. He couldn't take in what was being said around him. Q: TomEffects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

3

was unable to concentrate”). In addition, 20 questions were given before andafter the training to test the participants’ comprehension of subject andobject relative clauses (e.g., “The patient that ignored the doctor went out. Q:
The patient went out”). The results showed that the percentage of correct
answers for the subject and object relative clauses increased significantly inthe experimental group. In particular, learners with low proficiency
significantly improved their scores in object relative clause comprehension.
These studies indicate that when learners are repeatedly exposed to a
specific syntactic structure, they can unconsciously utilize the syntactic
structure activated in their brains. In this study, target sentences were notpresented visually but aurally with enough prosodic information (pitchchanges, pauses, etc.). Prosodic information can give significant cues forlistening comprehension (Kadota, 2007; Nakamura, 2012; Yoshikawa, 2006).
Sentences with such prosodic cues for syntactic construction (e.g., pausing at
the main clause, raising the pitch) are assumed to reduce the cognitive loadon the learner's syntactic processing.
2. Research Questions
The purpose of this study was to examine whether repeated shadowing ofobject relative clauses with prosodic structures (with pauses inserted
between the subject and verb) would facilitate Japanese EFL learners’
processing of the object relative clauses. In addition, this study exploredwhether the shadowing effect would differ according to individual English
ability.
3. Method
3.1 Participants
A total of 29 Japanese EFL undergraduate students (8 male and 21 female)participated in the study. Their proficiencies were measured using the
Oxford Quick Listening Test (OQLT; Allan, 2004). Their scores ranged from66 to 86 out of 100 possible marks (M = 76.83, S.D. = 4.33). After converting
the scores according to the Common European Framework of Reference for
Languages (CEFR), the 29 participants included 1 Intermediate (B1), 9 Upper-

4

NAKANISHI, Hiroshi

Intermediate (B2), 17 Advanced (C1) and 2 Proficient (C2) users. 1 Then
participants were divided into two groups according to CEFR scores: thegroup with lower level English proficiency (10 students, CEFR B1 and B2)
and the group with higher level English proficiency (19 students, CEFR C1and C2).
3.2 Procedure
All participants completed pre/posttests (i.e., pre/post-reading-aloud tests)
and shadowing training tasks. All tests were conducted in a CALL classroom,and the participants’ voices in the pre/posttests and shadowing training wererecorded on a computer.
3.3 Pre/Posttests
All participants were required to take a reading-aloud test before and after
the shadowing training. Tests contained 18 total sentences, including 12
target sentences (relative clause) and 6 filler sentences (see Appendix A). All
words used in the sentences were selected from the New JACET List of
8,000 Basic Words (Committee of Revising the JACET Basic Words, 2016).
Head nouns in all experimental sentences were animate, referring to Traxler,
Morris, and Seely (2002) and Hashimoto (2012), as inanimate head nouns
facilitate the processing of relational clauses. In additional reference toTraxler et al. (2002) and Hashimoto (2012), the head noun phrases in all
experimental sentences were unified into animate nouns so that the animate
nature of nouns would not affect the difficulty of processing relative clausesentences.
All target sentences that included a relative clause consisted of 12 words(e.g., “The farmer that the lady loved grows a crop in the field”), and filler
sentences consisted of 10 words (e.g., “The painter has been painting a
picture for his fans”). The sentences used between pretests and posttests
were different.
The reading-aloud test incorporated semantic judgment tasks, so half the1

Officially, CEFR scores should have been converted with both grammar test andlistening test scores. In this study, the grammar test was not conducted, so only thelistening scores were used to convert to CEFR.

Effects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

5

sentences were semantically correct (e.g., “The police that the people know
arrested the suspect in the crime”). Half were incorrect (e.g., “The climberthat the artist wears drew a picture in the studio”). A total of 18 sentenceswere presented to the participants on a paper. They were required to readeach sentence aloud and say “T” if the sentence was semantically plausible or“F” if it was implausible.
3.3 Shadowing Training Sessions
A total of 60 sentences constituted the shadowing sessions, including 40
target sentences (relative clause) and 20 fillers (see Appendix B). All words
used in the sentences came from the New JACET List of 8,000 Basic Words.
All target sentences consisted of 12 words (e.g., “The farmer that the lady
loved grows a crop in the field”), and filler sentences consisted of 10 words(e.g., “The writer has been writing the essay for the readers”).
For the sound models, a male native speaker of American English wasrecorded at a speaking rate of approximately 143 words per minute. The
pause (0.4 seconds) was inserted at appropriate syntactic boundaries (e.g.,“The farmer that the lady loved % grows a crop in the field.” : % indicates a
prosodic boundary) with free sound editing software, Audacity 3.2.1(Audacity Team, 2021). Figure 1 shows the waveforms and pitch tracks ofthe sentences.
Participants received the sentences printed onto paper to ensure sentence
processing. While following the text, they were required to repeat the soundmodel immediately after listening.
Figure 1
The student that the professor drinks % teaches his subject at the college.

The student that the professor

drinksteaches his

subject

atthecollege.

6

NAKANISHI, Hiroshi

4. Results and Discussion
4.1 Results of Pre/Posttest Performances for All Participants
Table 1 provides the descriptive statistics for accuracy (Score), reading
time (RT: sec.), and solution time (ST: sec.) in the reading-aloud tests. Score
shows the number of sentences processed correctly, RT indicates the reading
time per syllable for correct responses, and ST represents the response time
per sentence for correct responses. RT and ST were measured using Praat
software. RT was calculated by dividing the total time spent reading by the
number of syllables. ST was measured as the length of time fromimmediately after the end of the oral reading to the beginning of answering
the semantic judgment task.
Table 1
Descriptive statistics of the reading-aloud test data for all participants
Score

RT

ST

Test

Pre

Post

Pre

Post

Pre

Post

Avg.

7.65

8.63

0.25

0.25

1.79

1.58

Max.

4.00

3.00

0.12

0.10

0.39

0.39

Min.

12.00

12.00

0.46

0.46

5.78

5.78

S.D.

2.25

2.53

0.02

0.11

1.20

0.87

To measure the effects of shadowing training, Score, RT, and ST wereanalyzed statistically with t-tests. The results of the t-tests revealed that
posttest Scores were significantly better than those in the pretests ( t(28) =-6.86, p < .01). RT and ST in the posttests were significantly faster than thosein the pretests (RT: t(28) = 9.69, p < .01, ST: t(28) = 2.96, p < .01). This meansthat shadowing training improved participants’ accuracy, RT, and ST.
4.2 Results of Pre/Posttest Performances by Proficiency
Tables 2 and 3 show the reading-aloud test data (Score, RT, and ST) for
individuals with higher and lower proficiency.

Effects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

7

Table 2
Descriptive statistics of the reading-aloud test data for the lower proficiency
group
Score

RT

ST

Test

Pre

Post

Pre

Post

Pre

Post

Avg.

6.40

8.90

0.36

0.14

2.32

1.26

Max.

4.00

6.00

0.31

0.12

0.99

0.39

Min.

9.00

12.00

0.46

0.17

5.78

2.40

S.D.

1.90

1.91

0.05

0.02

1.43

0.62

Table 3
Descriptive statistics of the reading-aloud test data for the higher proficiency
group
Score

RT

ST

Test

Pre

Post

Pre

Post

Pre

Post

Avg.

8.00

10.21

0.32

0.18

1.61

1.31

Max.

3.00

7.00

0.21

0.10

0.60

0.40

Min.

12.00

12.00

0.40

0.40

3.47

2.09

S.D.

2.73

1.81

0.06

0.09

0.75

0.40

To measure the effects of shadowing by proficiency group, we did a twoway ANOVA analysis for lower/higher proficiency and pre/posttest.
Regarding score, the results of the two-way ANOVA revealed a significant
main effect in terms of proficiency (F(1, 54) = 5.80, p < .05, partial η2 = .097)
and pre/posttest (F(1, 54) = 15.19, p < .01, partial η2 = .220). The analysis
indicated no interaction between the variables of proficiency and pre/posttest at F(1, 54) = 0.06, ns., partial η2 = .001.

8

NAKANISHI, Hiroshi

As for RT, the results of the two-way ANOVA revealed a significant main
effect for proficiency (F(1, 54) = 0.95, p < .01, partial η2 = .000), whereas themain effect of the pre/posttest was not significant (F(1, 54) = 0.00, ns, partialη2 = .647). The RT revealed a significant interaction between proficiency
and testing, F(1, 54) = 4.93, p < .05., partial η2 = .084. Analysis of the simple
main effect of proficiency and testing disclosed that the RT in the posttest
was significantly faster than that in the pretest for the higher proficiency
group (p < .01) and the lower proficiency group (p < .01).
Regarding ST, the two-way ANOVA revealed no significant difference
between lower and higher proficiency groups, F(1, 54) = 2.22, ns, partial η2 =.040. However, a significant difference exists between the pretest andposttest, F(1,54) = 9.33, p < .01, partial η2 = .147. In addition, ST produced amarginally significant interaction between proficiency and testing, F(1, 54) =2.92, p = .09, partial η2 = .051. An analysis of the main effect of proficiency
and testing disclosed that the STs of participants with higher proficiency
were significantly faster than participants with lower proficiency in thepretest ( p < .05), but no significant difference was seen in the posttest.
The findings of this section can be summarized as follows:(1) For all participants, repeated shadowing of sentences containing object
relative clauses improved accuracy, RT, and ST in the posttest more than in
the pretest.
(2) The group with higher proficiency performed better than the group withlower proficiency when it came to accuracy and RT for sentence processingof object relative clauses. On the other hand, in terms of ST, the group withlower proficiency took longer than the group with higher proficiency in thepretest, yet this difference was not apparent in the posttest.
5. Conclusion and Further Study
The present study showed that prosody shadowing training facilitated theprocessing of object relative clauses. In particular, the comprehension speedof learners with low proficiency was accelerated.
Previous studies have shown that repeatedly exposing learners to visuallypresented constructions promotes automaticity in syntactic processing.
Further learning effects are also expected from the audio presentation of thestimulus sentences. The reason is that prosodic information (e.g., pitch, pause,Effects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

9etc.) in speech is a cue for syntactic construction, as shown in studies withnative English speakers (Schafer et al., 2000) and with second language
learners (Nakamura, 2012; Yoshikawa, 2006). This tendency is stronger
among second language learners, which is consistent with the "shallow
processing hypothesis" proposed by Clahsen & Felser (2006). This hypothesis
states that second language learners have incomplete syntactic processing
skills and are unable to construct complex syntactic structures like native
English speakers. They instead rely on non-structural cues such as lexical,
semantic, and contextual information for processing. Prosodic information ascues to syntactic construction (e.g., using a pause or raising the pitch at themain clause) are also assumed to reduce the cognitive load on learners'
syntactic processing (Nakamura, Arai & Harada, 2015). This study showedthat presenting speech rich in prosodic information directs the learners'
attention to prosodic aspects and that repeatedly shadowing complex
constructions such as object relative clauses facilitates sentence processing.
One of the limitations of this study, which has the nature of a pilot study, isthe need to set up a control group (e.g., a listening training group) in order to
see the unique effects of shadowing. In addition, it is also necessary tocompare acoustic analysis before and after shadowing to see whether
repeated shadowing not only improves processing accuracy and speed, butalso enables the realization of prosodic boundaries (indicated by %) on
syntactic boundaries (indicated by /) when reading aloud object relative
clauses as in the following sentences, “The farmer that the lady loved %/grows a crop in the field”.
Acknowledgment
This study was partially supported by JSPS Grant-in-Aid for Scientific
Research (C), (PI: Hiroshi Nakanishi, No. 19K00855).
References

Allan, D. (2004). Oxford Placement Test 2, Oxford: Oxford University Press.
Audacity Team. (2021). Audacity : Free Audio Editor and Recorder, Version 2.3.1.
retrieved from https://audacityteam.org.
Bock, K. (1986). Syntactic persistence in language production. Cognitive Psychology, 18,355-387.
Clahsen, H., & Felser, C. (2006). Grammatical processing in language learners, Applied

10

NAKANISHI, Hiroshi

Psycholinguistics, 27(1), 3–42.
Committee of Revising the JACET Basic Words. (Ed.). (2016). The new JACET list of
8,000 basic words. Tokyo, Japan: Kirihara Shoten.
Gibson, E. A. F. (1998). Linguistic complexity: Locality and syntactic dependencies,
Cognition, 68, 1–76.
Grodner, D., & Gibson, E. (2005). Consequences of the serial nature of linguistic input.
Cognitive Science, 29, 261–291.
Hashimoto, K. (2011). Syntactic processing of L2 English relative clause sentences: The
effect of proficiency. Annual Review of English Language Education in Japan, 22,
95–110.
Hashimoto, K. (2012). The effect of semantic information on L2 relative clauseprocessing as a function of proficiency [Paper presentation]. American Association
for Applied Linguistics 2012, Boston, MA, United States.
Kadota, S. (2007). Shadowing to ondoku no kagaku. [Science of shadowing and reading
aloud]. Tokyo: Cosmopier.
Kadota, S. (2015). Shadowing ondoku to eigo communication no kagaku [Science of
shadowing, oral reading, and English communication]. Tokyo: Cosmopier.
Kadota, S., Kawasaki, M., Shiki, O., Hase, N., Nakano, Y., Noro, T., Nakanishi, H., &Kazai, K. (2015). The effect of shadowing on the subvocal rehearsal in L2 reading: A
behavioral experiment for Japanese EFL learners. Language Education andTechnology, 52, 163–177.
Leeser, M. J., Brandl, A., & Weissglass, C. (2011). Task effects in second language
sentence processing research. In Trofimovich, P., & McDonough, K. (Eds.), Applying
Priming Methods to L2 Learning, Teaching and Research: Insights from
Psycholinguistics. pp. 179–198. Amsterdam: John Benjamins Publishing Company.
Morishita, M., Satoi, H., & Yokokawa, H. (2010). Verb lexical representation of Japanese
EFL learners: Syntactic priming during language production. Journal of the Japan
Society for Speech Sciences, 11, 29-43.
Morishita, M., & Yokokawa, H. (2012). The Cumulative Effects of Syntactic Priming inWritten Sentence Production by Japanese EFL Learners. Poster Session Presented
at the An¬nual Conference of the American Association for Applied Linguistics(AAAL), Boston, MA.
Nakamura, C. (2012). The effect of prosodic boundary in understanding English
sentences by Japanese EFL learners, Second Language, 11, 47–58.
Nakamura, C., Arai, M., & Harada, Y. (2015). Effect of prosody on resolving reduced
relative clause ambiguity in L2 sentence processing. Proceedings of the 44△th△
Annual Meeting of the English Language Education Society of Japan, 60–67.
Nakanishi, H., & Yokokawa, H. (2011). Determinant processing factors of recall
performance in reading span tests: An empirical study of Japanese EFL learners.
JACET Journal, 53, 93–108.
Nakanishi, H., Narumi, T., Hashimoto, K., & Yokokawa, H. (2019). How lexical familiarity
affects reading span: An empirical study with Japanese EFL learners. Journal of theJapan Society for Speech Sciences, 20.

Effects of Prosody Shadowing on Japanese EFL Learners’
Processing of Object Relative Clauses in English

11

Narumi, T., Hashimoto, K., Nakanishi, H., & Yokokawa, H. (2018). Lexical-semantic
driven processing during sentence comprehension by Japanese EFL learners:
Evidence from task effects on on-line processing of linguistic information. Journal of
the Japan Society for Speech Sciences, 19, 43–61.
Pickering, M. J., & Branigan, H. P. (1998). The representation of verbs: Evidence fromsyntactic priming in language production. Journal of Memory and Language, 39, 633651.
Sakakibara, K., & Yokokawa, H. (2015). Repeated exposure effects on Japanese EFL
learners’ relative clause processing: Evidence from a self-paced reading experiment.
Journal of the Japan Society for Speech Sciences, 16, 35–58.
Schafer, A., Carlson, K., Clifton, C., & Frazier, L. (2000). Focus and the interpretation ofpitch accent: Disambiguating embedded questions. Language and Speech, 43, 75–
105.
Traxler, M. J., Morris, R. K., & Seely, R. E. (2002). Processing subject and object relative
clauses: Evidence from eye movements. Journal of Memory and Language, 47, 69–
90.
Yoshikawa, H. (2006). Processing aural and visual embedded wh-sentences: An empirical
study for EFL learners [MA thesis]. Presented to the Graduate School of Language,
Communication and Culture, Kwansei Gakuin University.
Appendix A
Sample Target Sentences for Pre/Post-Reading-Aloud Test
The farmer that the lady loved grows a crop in the field.
The student that the expert drinks teaches his subject in the university.
The mother that the actor loves married her husband in the church.
The owner that the bakery cooked made the sandwich in the morning.
Appendix B
Sample Target Sentences for Shadowing Training
The actor that the daughter respects won an award for the movie.
The swimmer that the singer ate sings a song on the spot.
The singer that the swimmer follows sings a song from his heart.
The batter that the fans watch hits the ball in the stadium.