The role of selected lexical factors on confrontation naming accuracy and speed in children

1
The role of selected lexical factors on
confrontation naming accuracy and speed in
children

• Lisa King, M.A.
• Amy Strekas, B.A.
• Rochelle Newman, Ph.D.
• Nan Bernstein Ratner, Ed.D.
• University of Maryland, College Park

2
Lexical Access

• Many factors are thought to influence lexical
  access, including word frequency, neighborhood
  density, and neighborhood frequency.
• It is not known whether the effects of these
  lexical factors remain constant once a particular
  word is learned, or if the effects of these
  factors change with additional vocabulary
  development.

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Lexical factors

• Word frequency measure of how often a word
  occurs in the language
• Neighborhood density measure of how many words
  are phonologically similar to a particular word
• Let (dense) versus kept (sparse)
• Neighborhood frequency measure of the frequency
  with which phonological neighbors occur
• Weld (high) versus kept (low)

4
Lexical neighborhoods

• Some words are phonologically similar to many
  words
• E.g., Let is similar to bet, less, lent and
  light, among others
• Let resides in a dense neighborhood

5
Lexical neighborhoods

• Other words are similar to few words
• E.g., kept is similar only to three English words
  (crept, Celt and wept).
• The Neighborhood Activation Model (Luce Pisoni,
  1998) suggests that similarity to other words
  influences lexical organization.
• Words that sound similar are stored together in
  neighborhoods

6
Previous Findings

• High-frequency words are produced more quickly
  (Jescheniak Levelt, 1994) and more accurately
  (Vitevitch, 2002) than low-frequency words in
  adults.
• Word frequency effects are even stronger in
  children (Newman German, 2005)

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Previous Findings

• Words from dense neighborhoods tend to be
  produced more slowly (Luce Pisoni, 1998) but
  more accurately (Vitevitch, 2002) in adults.
• In children, words with high neighborhood
  frequency tend to be named more accurately
  (Newman German, 2002)

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Current Study

• To investigate
• The role of various lexical factors on naming
  accuracy and speed in children
• Word frequency
• Neighborhood density
• Neighborhood frequency
• How these lexical factors change with lexical
  development

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Participants

• 69 typically-developing children
• 25 5-year-olds, 24 7-year-olds, 20 9-year-olds
• 25 adults
• Divided into three vocabulary groups
• Adult
• High Vocabulary Children(23 children gt140 raw
  score on PPVT)
• Low Vocabulary Children (23 children lt100 raw
  score on PPVT)

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Procedure

• Children named pictures as they appeared on a
  computer screen
• Responses were coded according to accuracy and
  reaction time
• Peabody Picture Vocabulary Test - III (Dunn
  Dunn, 1997)

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Stimuli

• Stimuli were pictures of 107 common nouns verbs
• These could be divided into 6 subsets . . .
• Words high vs. low in word frequency
• Words high vs. low in neighborhood density
• Words high vs. low in average frequency of
  neighbors
• This can be thought of as a measure of the
  frequency with which the sound pattern in general
  is encountered.

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Words that are
High in frequency
Low in frequency
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Words that have
Sparse neighborhoods
Dense neighborhoods
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Words with
High neighborhood frequency
Low neighborhood frequency
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Accuracy

• Proportion of word-finding errors was calculated
  for each child
• Correct responses
• Intended responses (most commonly-used name for
  picture)
• Synonyms (garbage for trash)
• Elaborations (Canadian goose for goose)
• Word finding errors
• Wrong word (money for dime)
• Circumlocution (its the thing you use to X)
• I dont know

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Reaction time

• Reaction times were calculated from presentation
  of picture to onset of speech
• Reaction times were only calculated on items
  named as intended

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Stimuli

• 107 pictures of common nouns and verbs
• Represent vocabulary known by 5 years of age
• Divided into 6 subsets
• Word frequency (high vs. low)
• Neighborhood density (dense vs. sparse)
• Neighborhood frequency (high vs low)

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Word FrequencyError Rate

• Low Frequency words were produced with less
  accuracy than high frequency words, F(1,
  68)48.96, plt.0001
• Individuals with larger vocabulary size made
  fewer errors, F(2,68)20.67, plt.0001
• The interaction between frequency and vocabulary
  size was significant, F(2,68)11.85, plt.0001
• The effect of wordfrequency decreased as
  vocabulary increased

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Word FrequencyReaction Times

• High frequency words were produced more quickly
  than low frequency words, F(1,68)70.11, plt.0001
• Individuals with larger vocabulary size responded
  more quickly than those with a smaller
  vocabulary, F(2,68)22.19, plt.0001
• The interaction between frequency and vocabulary
  size was significant, F(2,68)8.98, plt.0005
• The effect of wordfrequency decreased as
  vocabulary increased

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Neighborhood FrequencyError Rate

• Individuals made more errors on items with low
  neighborhood frequency than on those with high
  neighborhood frequency, F(1,68)21.13, plt.0001
• Individuals with a larger vocabulary size made
  fewer errors than those with a smaller
  vocabulary, F(2,68)28.39, plt.0001
• There was no interaction between neighborhood
  frequency and vocabulary size, Flt1

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Neighborhood FrequencyReaction Times

• Individuals responded more quickly to words with
  high neighborhood frequency than to words with
  low neighborhood frequency, F(1,68)17.22,
  plt.0001
• Individuals with a larger vocabulary responded
  more quickly than those with a smaller
  vocabulary, F(2,68)25.96, plt.0001
• There was no interaction between neighborhood
  frequency and vocabulary size, Flt1

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Neighborhood DensityError Rate

• Individuals made more errors on low neighborhood
  density words than on high, F(1,68)32.82,
  plt.0001
• Individuals with a larger vocabulary size made
  fewer errors than those with a smaller
  vocabulary, F(2,68)29.36, plt.0001
• The interaction between neighborhood density and
  vocabulary size was not significant, Flt1

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Neighborhood DensityReaction Times

• There was no effect of neighborhood density on
  reaction times, Flt1
• Individuals with a larger vocabulary size
  responded more quickly than individuals with a
  smaller vocabulary, F(2,68)17.29, plt.0001
• There was no interaction between neighborhood
  density and vocabulary size for reaction time, Flt1

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Discussion

• In general, individuals were more accurate in
  responding to high frequency, high neighborhood
  density, and high neighborhood frequency items.
• Individuals responded more quickly to high
  frequency, high neighborhood frequency items.

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Discussion

• Children with low vocabulary were particularly
  impaired on low-frequency words relative to
  high-frequency words.
• Older children and adults, those with larger
  vocabulary sizes, show a relatively greater
  increase in their performance on less frequent
  words.
• This suggests that increased exposure and usage
  of these words facilitates retrieval.

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Discussion

• Both children and adults show effects of word
  frequency, neighborhood density and neighborhood
  frequency on the speed and accuracy of lexical
  naming.
• Children with lower vocabularies (who also tended
  to be the youngest in the study) were slower and
  less accurate than those with higher vocabularies
• Word frequency had a marked effect on their
  performance.

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Conclusions

• Despite the fact that the words were selected so
  as to all be within the vocabularies of children
  in this age range, children with lower
  vocabularies were especially hampered by words
  with lower frequency.  Yet they showed comparable
  effects to adults on neighborhood-based
  properties.
• This might suggest that as one's vocabulary
  becomes richer and more varied, frequency effects
  become smaller.  
• In contrast, neighborhood properties mayhave
  more to do with whether a child knows a word or
  not, but not on the depth or richness of that
  knowledge.

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References

• Dunn, L. M., Dunn, L. M. (1997). Peabody
  Picture Vocabulary TestIII. Circle Pines, MN
  American Guidance Service.
• Jescheniak, J. D., Levelt, W. J. M. (1994).
  Word frequency effects in speech production
  Retrieval of syntactic information and of
  phonological form. Journal of Experimental
  Psychology Learning, Memory Cognition, 20(4),
  824-843.
• Luce, P. A., Pisoni, D. B. (1998). Recognizing
  spoken words The Neighborhood Activation Model.
  Ear Hearing, 19(1), 1-36.
• Newman, R. S., German, D. J. (2002). Effects of
  lexical factors on lexical access among typical
  language-learning children and children with
  word-finding difficulties. Language Speech,
  43(3), 285-317.
• Newman, R. S., German, D. J. (2005). Life span
  effects of lexical factors on oral naming.
  Language Speech, 48(2), 123-156.
• Vitevitch, M. S. (2002). The influence of
  phonological similarity neighborhoods on speech
  production. Journal of Experimental Psychology
  Learning, Memory Cognition, 28, 735-747.

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Acknowledgments

• Recipient of a 2006 ASHA Student Research Travel
  Award
• The following individuals contributed by
  assisting in collecting or coding the data
• Robyn Amendola, Shannon Auxier, Emilie
  Clingerman, Hannah Couch, Nicole Craver, Kristin
  Crawford, Casey DiBicarri, Shoshana Dickler,
  Annie Ferruggiaro, Darlene Foster, Sarah Haszko,
  Grace Ji, Lacey Kahner,  Hannah Kim, Arielle
  Laurie, Amanda McAdoo, Michele McEntee, Heather
  McIntosh, Sarah Michael, Abimbola Odukoya, Ashley
  Orkin,  Jillian Parry, Shannon Rice, Andrea
  Riffenacht, Kate Shapiro, Emily Singer, Audry
  Singh, Stephanie Souder, Lisa Surrell, Rachel
  Weitzner, Patricia Yudd, Jenni Zobler