1. Background
 The standard model of phonological short-term memory (e.g., Baddeley,
1986) states that novel strings of sounds are passively stored in short-term
memory and will decay unless refreshed via articulatory rehearsal. The longer
these memory traces are held in short term memory, the more likely they are
to be encoded into long-term memory, thus increasing vocabulary size.
 Early investigations have found correlations between nonword repetition
(NWR) tasks, speech rate, and vocabulary; more specifically, NWR accuracy
has predicted vocabulary growth and speech rate. However, to our
knowledge, there have been no studies exploring the relationship between
articulation rate during NWR tasks and vocabulary growth in bilingual
children.
 The purpose of this study was to examine the role of articulation rate in NWR
performance and vocabulary size in bilingual kindergartners.
Research Questions
 Q1 To what degree are articulation rate, nonword repetition accuracy, and
vocabulary size related in the second language, English, of Spanish-English
bilingual kindergarteners?
 Q2 Do these relationships change over time?
 Q3 What are the best predictors of future performance?
Nonword repetition articulation rate and accuracy: Relationship with second language vocabulary in
Spanish-English bilingual kindergarteners
Maria Boy Skipsey1, Emily P. Mitchell1, Todd A. Gibson1, Linda Jarmulowicz2, D. Kimbrough Oller2
1 Louisiana State University, Department of Communication Sciences & Disorders, Baton Rouge, Louisiana
2University of Memphis, School of Communication Sciences & Disorders, Memphis, Tennessee
Methods
 Participants: 34 Spanish-English bilingual kindergarteners with typical
development. Children were from a low socioeconomic background. There
were 8 girls and 26 boys.
 Measures:
• Phonological Short Term Memory in English: measured by a subset of the
NWR task used by Gathercole, Willis, Emslie, & Baddeley (1991):
30 items of 2-, 3-, and 4- syllables. Scores based on accuracy at whole
word level.
• Articulation Rate: syllables-per-second was calculated by dividing the
number of syllables actually produced by the duration of the production.
• Receptive Vocabulary: measured by the Peabody Picture Vocabulary Test
(PPVT-III), a picture-pointing task, and its Spanish equivalent, the Test de
Vocabulario en Imágenes Peabody (TVIP).
 Procedures: Children were tested at school at the beginning and at the end of
the school year.
 Analysis: Partial correlations controlling for age were used to identify
relationships between target variables; Fisher’s Z transformations were
performed to compare between correlations.
Results
 Q1: Articulation rate did not significantly correlate with any other variable.
NWR accuracy and English vocabulary knowledge correlated concurrently at
pre- and posttest. Concurrent correlations between Spanish vocabulary and
NWR accuracy were not statistically significant.
 Q2: Fisher’s Z transformation showed no change in the size of the correlation
between NWR accuracy and English vocabulary across the school year,
Z = .40, p = .69.
 Q3: NWR accuracy at the end of the school year was predicted by both
English and Spanish vocabulary to similar degrees, Fisher’s Z = .63, p = .53.
References
Baddeley, A.D. (1986) Working memory. Oxford: Clarendon Press.
Gathercole, S., Hitch, G., Service, E., & Martin, A. (1997). Phonological short-
term memory and new word learning in children. Developmental Psychology,
33(6), 966-979.
Dunn, L. M., & Dunn, L. M. (1997). Peabody Picture Vocabulary Test: PPVT-
IIIB. Circle Pines, MN: American Guidance Service.
Padilla, E. R., Lugo, D. E., & Dunn, L. M. (1986). Test de Vocabulario en
Imágenes Peabody (TVIP). Circle Pines, Minnesota: AGS.
Acknowledgements
This work was funded by a grant from NICHD (R01 HD046947) to
D. Kimbrough Oller, PI, and by the Plough Foundation. Special thanks to the
Memphis City Schools.
Partial Correlations Controlling for Age
1 2 3 4 5 6 7 8
1. NWR Acc pre —
2. NWR Acc post .607* —
3. NWR Rate pre -.048 -.041 —
4. NWR Rate post .151 .124 .175 —
5. Eng Voc pre .576* .338** -.116 .121 —
6. Eng Voc post .299 .500* .031 .134 .481* —
7. Span Voc pre .219 .475* -.037 -.073 .315 .454* —
8. Span Voc post .180 .277 .300 .041 .154 .340** .475* —
Note.*p<.05; **p<.01
Participants
N Mean Std. Deviation
Children’s Age 34 5.50 0.35
Mother’s Education
(years)
32 8.21 2.90
Exposure to English
(age)
34 3.13 1.59
Eng Voc pre
Standard score
34 62.70 17.18
Eng Voc post
Standard score
34 71.85 14.13
Span Voc pre
Standard score
34 86.30 16.13
Span Voc post
Standard score
34 89.50 15.49
Syll per sec pre 34 3.93 0.35
Syll per sec post 34 3.93 0.33
Discussion
 Results of the current study did not support predictions of the standard model
of short term memory. Articulation rate did not correlate with either
vocabulary growth or NWR task performance at the end of the school year.
 NWR accuracy and English vocabulary, but not Spanish vocabulary,
correlated concurrently at pre- and posttest. This suggests that concurrent
NWR performance, which was tested based on items following the rules of
English phonology, was related to language-dependent phonological
knowledge stored in long term memory.
 Both English and Spanish vocabulary predicted future NWR accuracy
suggesting an all-purpose vocabulary learning ability that likely supports
performance in NWR tasks.