What

1

What Mice Trap tells us about the mental
lexicon Carolyn J. Buck-Gengler1,3, Lise Menn2,3,
and Alice F. Healy1,3 University of Colorado at
Boulder 1Department of Psychology 2Department
of Linguistics 3Institute of Cognitive Science
Abstract Two experiments focused on the effect of
noun regularity on the task of producing a
singular form from a plural or the reverse.
Experiment 1 used English Experiment 2 used a
miniature artificial language in which word
frequency and form were controlled. Subjects
learned the words in the artificial language
before proceeding to the test phase of Experiment
2. In the test phase of both experiments,
subjects were given one of the two forms
(singular or plural) and required to produce
either the same form or the opposite form. In
half the trials the grammatical number of the
picture and the required response matched, and in
half the number did not match. In Experiment 1,
response time per letter was faster when the
number of cue and required response matched than
when they differed, especially for the
irregulars. In Experiment 2, there were also
significant effects of matching, but these
effects were not influenced by either word
frequency or regularity. From these results we
conclude that the preference for irregular plural
as first element of noun-noun compounds can be
explained by processing factors which hold for
both children and adults in both natural and
artificial languages. No appeal to innate grammar
is required to explain the similarity between
this aspect of child and adult linguistic
behavior. Background Regular and irregular nouns
behave differently Example noun-noun compounding
in English regular irregular singular rat
catcher mouse catcher plural rats catcher mice
catcher General rule The first noun must be
singular (e.g., rat catcher, toy box, but not
rats catcher, toys box, even when talking about
multiple rats or toys), but the plural of
irregular nouns is also acceptable. Pinker (e.g.,
1994 146-7) argues that the rule is likely to be
innate because children obey it (Gordon, 1985),
even without being exposed to adult examples of
irregular plurals as first elements of
compounds. Gordon (1985) When prompted with
phrases like What do you call someone who eats
ltXgt?, where X was either a regular or irregular
plural noun, children frequently used plural when
primed with an irregular plural, but almost never
used plural when primed with a regular plural.
Findings were explained in terms of an innate
grammar, specifically Level Ordering (e.g.,
Kiparsky, 1982). Alternate explanation
Processing difficulty Buck-Gengler, Menn, and
Healy (2001) Elicited noun-noun compounds
(similar to Gordon, 1985) from adults Subjects
saw fill-in-the-blank sentence, responded with
compound a TUB holding X is a _____ X was a
singular or plural regular or irregular English
noun Example duck/ducks/goose/geese Subjects
produced far more plurals for the first noun of
the compound when the cue was an irregular plural
(geese) than when it was a regular plural (ducks)
or either type of singular (goose/duck). When
subjects did produce singular first forms (goose
tub/duck tub) RTs were significantly longer for
irregular plural cues than for the other three
kinds of cue. Preference for producing irregular
plurals as first elements of compounds in such
elicitation tasks can therefore be explained by
processing difficulty Goose is harder to access
from geese than duck is from ducks (as might be
predicted by, e.g., Allen Badecker, 2002, or
Levelt, Roelofs, Meyer, 1999).
The Current Experiments Main Task Given either
a singular or a plural of a noun, produce either
same or opposite form Experiment 1 English
similar set of words as in Buck-Gengler et al.
(2001) Stimuli Pictures representing a matched
set of imageable English nouns Irregular Regular
child children car cars foot feet fork forks goos
e geese gun guns louse lice letter letters man me
n match matches mouse mice moon moons ox oxen owl
owls tooth teeth tree trees Matched on
frequency, first letter, length Experiment 2
Miniature artificial language Why an artificial
language? To control for factors in real
languages (e.g., word frequency, type of
irregularity, aspects of form including onset,
length, etc., and other idiosyncrasies) that
could be contributing to the response. Description
of artificial language Structure -- controlled
for form and frequency Form singular plural
CVCV C1 ? C2, V1 ? V2 Plural method C
k,g,f,v,m,n,s,z,t,d,p,b Noun
type Prefix Infix V a,i,o,u Regular e-CVCV C
-e-VCV Irregular C--VCV -CVCV is
a nonpredictable vowel (not e) Frequency 12
low frequency regular 4 low frequency
irregular 4 high frequency regular 4 high
frequency irregular Stimuli Pictures
representing the English concept for each
artificial language word
Method Both experiments 2 phases Phase 1 Exp.
1 familiarization with pictures see picture,
type word go through list twice Exp. 2 Learn
miniature artificial language words Phase 2 Main
task Participants and Apparatus 16 (E1), 24
(E2) native speakers of English Presented on
computer Responses and RTs recorded by
computer Main task In both experiments,
participants saw a picture and a
fill-in-the-blank phrase which was either the
number 1 or the number 4 followed by a blank
(in the English experiment the numbers were
spelled out). Example fill-in-the-blank phrases
one _____ or four ____ (Exp. 1) 1_____
or 4 ______ (Exp. 2) Participants typed the
appropriate form of the English or artificial
language word representing the picture to go with
the number in the fill in the blank phrase. For
example If they saw a picture of four trees
and one ____ (Exp. 1) or 1 ____ (Exp.
2) they responded by typing tree (Exp.
1) or bidu (Exp. 2) Design Between subjects
factor (Exp. 2) Plural method of regular
(prefix infix) Within subjects factors Noun
type (regular, irregular) Grammatical number of
response (singular, plural) Match (Response
grammatical number match/not match cue
picture) Frequency (high, low) (Exp. 2 only)
Measure Time/letter (Total Response Time/
letters in the word) Scoring Only correct typed
trials (no backspacing/correction) included
Results Exp. 1 (English) Main effects for
Response Time/Letter Regulars faster than
irregulars Additional time is required when the
picture number and response number dont
match Interactions Exp.
2 (Miniature Artificial Language) Main effects
for Response Time/Letter Regulars faster than
irregulars Additional time is required when the
picture number and response number dont
match Conclusion From these and
previous results we conclude that the frequently
reported preference for irregular plural as first
element of noun-noun compounds can be explained
by processing factors (i.e., the accessibility of
the singular from the plural) that hold for both
children and adults, and in both natural and
artificial languages. No appeal to innate grammar
is required to explain the similarity between
child and adult performance on this aspect of
linguistic behavior. More generally, the closer
two forms of the same word (lemma) are to each
other, the faster one will be accessed from the
other. Unlike English, the artificial language
ensured that the difference in form between
singular and plural was equivalent for both
regulars and irregulars. With this control, weve
teased apart the issues of regularity and
similarity, and have shown them to have separate,
non-interacting effects. In addition, infixation
and affixation appear to be equivalent when
transparency is controlled.
Letters in irregular singulars are typed faster
than those in irregular plurals, but letters in
regular plurals are typed faster than those in
regular singulars.
Shows the two main effects moreover, the
interaction approaches significance Extra
response time is needed when cue and response
numbers dont match for irregular nouns.
Shows the two main effects (interaction is not
significant).
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References Allen, M. Badecker, W. (2002).
Inflectional regularity Probing the nature of
lexical representation in a cross-modal priming
task. Journal of Memory and Language, 46,
705722. Buck-Gengler, C. J., Menn, L., Healy,
A. F. (2001). Mice Trap A new explanation for
irregular plurals in noun-noun compounds.
Proceedings of the Twenty-Third Annual Conference
of the Cognitive Science Society (pp. 140-145).
Mahwah, NJ Erlbaum. Gordon, P. (1985).
Level-ordering in lexical development. Cognition,
21(2), 73-93. Kiparsky, P. (1982). From cyclic
phonology to lexical phonology. In H. v. d. Hulst
N. Smith (Eds.), The Structure of Phonological
Representations (pp. 131-175). Dordrecht, The
Netherlands Foris Publications. Levelt, W. J.
M., Roelofs A., Meyer, A. S. (1999). A theory
of lexical access in speech production.
Behavioral and Brain Sciences, 22, 175. Pinker,
S. (1994). The Language Instinct. New York W.
Morrow and Co.
Learning the Miniature Artificial Language
Subjects saw a picture and associated word, and
typed the word 12 words (mixture of high and
low frequency, singular and plural, regular and
irregular) formed a subset After each subset,
quiz to reinforce learning, with feedback 8
subsets comprised one round within the 8 subsets
each word was seen either once (low frequency) or
4 times (high frequency) After one round of
learning and quizzes, test of all words, with
feedback When criterion (90) reached on test,
proceeded to main task If criterion not
reached, repeated learn/quiz, with different
order and grouping of words F All Ss learned to
criterion within 7 rounds over half learned to
criterion in 2 or 3 rounds.
__________________________________ Acknowledgments
This research was supported in part by Army
Research Institute Contract DASW01-99-K-0022 and
Army Research Office Grant DAAG55-98-1-0214 to
the University of Colorado (Alice Healy,
Principal Investigator Lyle Bourne, Co-Principal
Investigator). This research was also supported
in part by a Student Research Award from the
Institute of Cognitive Science to the first
author.