characterising kinds and instances of kinds: erp reflections
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This article was downloaded by: [Wayne State University]On: 26 November 2014, At: 19:14Publisher: RoutledgeInforma Ltd Registered in England and Wales Registered Number: 1072954 Registeredoffice: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK
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Characterising kinds and instances ofkinds: ERP reflectionsSandeep Prasada a , Anna Salajegheh b , Anita Bowles b & DavidPoeppel ca Department of Psychology , Hunter College , New York, NY,USAb Cognitive Neuroscience of Language Laboratory , University ofMaryland , Baltimore, MD, USAc Cognitive Neuroscience of Language Laboratory; Departmentof Biology; and Department of Linguistics , University ofMaryland , Baltimore, MD, USAPublished online: 08 Feb 2008.
To cite this article: Sandeep Prasada , Anna Salajegheh , Anita Bowles & David Poeppel (2008)Characterising kinds and instances of kinds: ERP reflections, Language and Cognitive Processes,23:2, 226-240, DOI: 10.1080/01690960701428292
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Characterising kinds and instances of kinds:
ERP reflections
Sandeep PrasadaDepartment of Psychology, Hunter College, New York, NY, USA
Anna SalajeghehCognitive Neuroscience of Language Laboratory, University of Maryland,
Baltimore, MD, USA
Anita BowlesCognitive Neuroscience of Language Laboratory, University of Maryland,
Baltimore, MD, USA
David PoeppelCognitive Neuroscience of Language Laboratory; Department of Biology; and
Department of Linguistics, University of Maryland, Baltimore, MD, USA
Syntactic and semantic information are computed online in a manner such thatelectrophysiological methods can detect distinct processes within a few hundredmilliseconds of a word. The amplitude of the N400 response has been shown toreflect semantic integration of a word in the context of a preceding word,sentence, and discourse. We show, in a combined behavioural and ERP study,that the N400 amplitude to the same word, in nearly identical sententialcontexts, is modulated as a function of subtly different morphosyntacticenvironments that condition either a generic (grass is green) or nongeneric (thegrass is green) reading. The results suggest that N400 amplitude reflects not
Correspondence should be addressed to Sandeep Prasada, Department of Psychology,
Hunter College, CUNY, 695 Park Avenue, New York, NY 10021, USA.
E-mail: [email protected]
We thank Nina Kazanina for help with the script and Elaine Dillingham, Susannah Hoffman
and Maura Pilotti for help conducting the behavioural experiments. This work was supported by
an NIH grant to DP (R01DC 05660) and a startup grant from Hunter College to SP. SP also
received infrastructure support from RCMI grant RR03037 from the National Center for
Research Resources (NIH) to the Gene Center at Hunter College. During part of the
preparation of this manuscript, DP was a Fellow at the Wissenschaftskolleg zu Berlin.
LANGUAGE AND COGNITIVE PROCESSES
2008, 23 (2), 226�240
# 2007 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business
http://www.psypress.com/lcp DOI: 10.1080/01690960701428292
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only the existence of a semantic computation but can reflect processes relevantto the type of semantic relation being computed. Specifically, it is sensitive towhether a word is interpreted as characterising a kind/type or an instance of akind/token of a type.
A central problem in language comprehension involves when and how
incoming information is incorporated into existing semantic representations.
Event-related potentials (ERP) provide one tool for investigating this
question. Findings indicate that the N400 response reflects the processing
of semantic information, and that its amplitude varies with the degree to
which a word fits the preceding word or sentential context (e.g., Federmeier
& Kutas, 1999; Friederici, Pfeiffer, & Hahne, 1993; Hagoort & Brown, 1994;
Holcomb, Kounios, Anderson, & West, 1999; Kutas, 1993; Kutas & Hillyard,
1980, 1984; Neville, Nicol, Barss, Forster, & Garrett, 1991; Osterhout &
Mobley, 1995; Van Petten, 1993, 1995). Research by van Berkum, Hagoort,
and Brown (1999) shows that this sensitivity to semantic fit extends to extra-
sentential discourse contexts.
In the present study, we investigate whether the type of semantic relation a
given word has to the preceding linguistic context influences the N400.
Specifically, we investigate how N400 amplitude varies when a critical word
characterises a kind (e.g., banana) or an instance of a kind (e.g., this banana).
Kutas and Hillyard (1980) demonstrated that N400 amplitude varied with
the plausibility and/or predictability of a word within a given context. Using
sentences such as (1) and (2), they found that words such as beard in (1)
elicited a reduced N400 in comparison to less plausible or predictable words
such as city (2).
(1) He shaved off his moustache and beard.
(2) He shaved off his moustache and city.
This result has been extended in a number of ways. Studies consistently find
that more plausible and more predictable words elicit smaller N400
amplitudes. These data suggest that N400 amplitude reflects processes
involved in the integration of semantic information into the existing
context.1
However, these studies do not indicate whether N400 amplitude also
reflects the type of semantic relation a word has to its preceding context. A
notable exception are studies which have investigated the is a relation in
categorisation (A banana is a fruit/A banana is not a fruit/A banana is a
1 Debate continues concerning the nature of the processes involved in semantic integration
and their contribution to the N400; however, there is consensus that ease of integration of
semantic information is reflected in the N400 signal.
GENERICITY AND THE N400 227
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vehicle/A banana is not a vehicle) (e.g. Fischler, Bloom, Childers, Roucos, &
Perry, 1983). These studies show that the N400 is sensitive to whether the
subject category is a member of the predicate category, providing evidence
that N400 amplitude is sensitive to category inclusion. The present study
investigated whether N400 amplitude is also sensitive to the difference
between the relation involved in characterising a kind (or type) and
characterising an instance of a kind (or token of a type).
We held the critical word constant across sentences and manipulated its
semantic relation to the preceding context. In one set of sentences, the
critical word characterised a kind (3), whereas in another set, the same
critical word characterised an instance of that kind (4). We chose such
sentences because they have drastically different interpretations despite
identical content words and virtually identical surface forms.2 The inter-
pretations of these sentences differ along a number of (related) dimensions.3
First, whereas the predicate in (3) characterises a kind, the predicate in (4)
characterises a specific instance of a kind. Second, whereas (3) has a
determinate truth-value, (4) does not. It may be true of some banana but not
others, or a banana only at a given time. Finally, generics have discourse
independent interpretations, whereas nongenerics do not.
(3) Bananas are yellow.
(4) This banana is yellow.
(5) Bananas are green.
(6) This banana is green.
These differences in interpretation indicate that the critical word (yellow)
must be integrated with representations constructed based on the preceding
sentential context in different ways for generics and nongenerics. Further-
more, the manner in which the critical word is integrated depends not only
on whether the subject refers to a kind or to instances of a kind, but also on
2 Instead of choosing sentences such as (4), it would have been possible to choose nongeneric
sentences such as The bananas are yellow, which are even more similar to the generic sentences in
surface form. Given our interest in the semantic interpretation of generic and nongeneric
sentences, we chose to manipulate whether a single kind or a single instance of a kind was being
characterised. Thus, we held the number of things being characterised constant but manipulated
the nature of the thing being characterised (1 kind/1 instance). Since kinds contain indefinitely
many instances, it is not possible to match the number of instances referred to in the generic and
nongeneric conditions. It should be noted that 25% of our generic sentences were about kinds
that are referred to by mass nouns. For these sentences, the generic and nongeneric sentences
differed only in the presence/absence of a determiner (Grass is green/The grass is green).3 For a review of the ways in which generic sentences can differ from nongeneric sentences,
see Krifka et al. (1995). Here we concentrate on only those differences that are relevant to the
sentences used in our experiment.
228 PRASADA ET AL.
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the characterising word. For example, abundant must be interpreted
differently than yellow with respect to the kind BANANA.4
In sum, the interpretations of generic and nongeneric sentences differ in a
number of ways. If N400 amplitude is sensitive to the type of semanticrelation into which a critical word enters, then characterising words in
generic and nongeneric sentences may elicit distinct N400 responses.
Comparing the processing of generic and nongeneric sentences also
provides a theoretical basis for distinguishing the effects of predictability and
genericity. In true generic sentences (3), the critical word must refer to a
characteristic property of the kind. No such constraint applies to the critical
word in the corresponding nongeneric sentence (4). In a nongeneric sentence,
the critical word could refer to a characteristic property, or an uncharacter-istic or temporary property (e.g., green, wet). Thus, the critical word in true
generic sentences (3) should be more predictable than the same word in
corresponding nongeneric sentences (4). In contrast, critical words cannot
refer to an uncharacteristic property if a sentence is generic, but may do so if
the sentence is nongeneric. Consequently, critical words that refer to an
uncharacteristic property should be more predictable in nongeneric sen-
tences (6) than in generic sentences (5). These predictions concerning
genericity and predictability were tested behaviourally in Experiments 1Aand 1B and the reflections of genericity and predictability were tested
electrophysiologically in Experiment 2.
EXPERIMENT 1A
In Experiment 1A we used the Cloze procedure to determine if the
predictability of characteristic and uncharacteristic properties varies in
accordance with constraints on the interpretation of generic and nongeneric
sentences.
Method
Participants. Eighty-nine native speakers of American English partici-
pated.
Stimuli. Forty sets of four sentences were constructed. Each set
contained (i) a generic sentence with a characteristic property of the kind
(GC) (Bananas are yellow); (ii) a corresponding nongeneric sentence with thesame kind and characteristic property (NC) (The banana is yellow); (iii) a
4 Context can also influence interpretation. In principle, one could interpret sentences such
as (4) and (6) generically, however, this interpretation is difficult in the absence of a supporting
context. The present experiment did not provide such a context.
GENERICITY AND THE N400 229
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generic sentence with the same kind, but an uncharacteristic property of the
kind (GU) (Bananas are green); and (iv) a corresponding nongeneric
sentence with the same kind and uncharacteristic property (NU) (The
banana is green). All generic sentences were three words long, the
corresponding nongenerics four words long. The uncharacteristic properties
chosen were properties that were plausible (e.g., bananas can be green).
Finally, the generics used were sentences such as (3) in which we understand
there to be a principled connection between the kind and the characteristic
property over and above any statistical connection between the two (Prasada &
Dillingham, 2006). The full set of sentences is given in Appendix A. For the
Cloze procedure, the final word of each sentence was replaced with a blank.
Two lists were constructed so that each list contained either the generic or
nongeneric version of an item.
Procedure. Participants were asked to read the sentence fragments to
themselves and fill in the blank with the first word that came to mind.
Results and discussion
Cloze probabilities for the critical words are given in Table 1.5 Characteristic
properties were predictable and uncharacteristic properties highly unpredict-
able.
Because of the lack of variability, no statistical test was possible, but it is
clear that characteristic words were more predictable than uncharacteristic
words and, crucially, that there was no difference in the predictability of
uncharacteristic words in generic and nongeneric contexts. A t-test showed
no difference in the predictability of characteristic words in generic and
nongeneric contexts. Furthermore, their distributions had virtually identical
standard deviations, skewness, and kurtosis. In sum, the critical words in our
5 Due to clerical errors on 2 items, the results are based on 38 items.
TABLE 1Cloze probabilities of critical words as a function of sentence type
and property type. Ranges given in parentheses
Property type
Characteristic Uncharacteristic
Sentence type
Generic 0.4453 (0�1) 0
Nongeneric 0.4222 (0�0.8696) 0.0029 (0�0.0011)
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generic and nongeneric sentences do not differ in their Cloze probabilities. If
they elicit distinct N400 amplitudes, the differences could not be attributed
to differences in the predictability of the critical words. We were concerned,
however, that the Cloze procedure may not provide a sensitive enough
measure of predictability, and thus also measured predictability in a ratings
task (Experiment 1B).
EXPERIMENT 1B
Participants. Sixteen native speakers of American English participated.
Stimuli. Set of sentences described above.
Procedure. Participants were presented with all 40 sets of sentences in
random order and asked to rate how predictable the last (critical) word of
the sentence was on a 7-point scale. Sentences were presented in sets with the
generic and corresponding nongeneric sentences presented one after the
other (with order of presentation counterbalanced across sets) to highlight
predictability differences. This potentially overestimates the predictability of
these words when the sentences are presented in random order as in
Experiment 2. Because our purpose was to determine if there was an effect of
genericity that could not be attributed to predictability, it was desirable to
use as sensitive a measure of predictability as possible. The order of sentences
with characteristic and uncharacteristic properties was counterbalanced.
Results and discussion
Mean ratings for predictability of the critical word in the four conditions
are given in Table 2. A 2�2 within-subjects ANOVA was conducted
TABLE 2Mean predictability ratings of the characterising property as a function
of sentence type and property type
Property type
Characteristic Uncharacteristic
M (SD) M (SD)
Sentence type
Generic 6.24 (0.44) 1.85 (0.68)
Nongeneric 5.79 (0.56) 3.37 (0.95)
GENERICITY AND THE N400 231
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with variables of sentence type (generic/nongeneric) and property type
(characteristic/uncharacteristic). Participants’ ratings were the dependent
measure. Main effects of property type, F(1, 15)�274.57, pB.001, and
sentence type, F(1, 15)�23.83, pB.001 were found. There was also asignificant interaction, F(1, 15)�76.00, pB.001, indicating that the critical
word was rated as more predictable in generic than in nongeneric sentences
when the word referred to a characteristic property, F(1, 15)�10.92,
pB.005, but was rated as less predictable when the word referred to an
uncharacteristic property, F(1, 15)�75.03, pB.001. Finally, as hypothesised,
the characteristic property was more predictable than the uncharacteristic
property in both generic, F(1, 15)�363.84, pB.001, and nongeneric,
F(1, 15)�102.41, pB.001 sentences. In sum, the predictability of character-istic and uncharacteristic words was in accordance with the constraints on
interpretation imposed by generic and nongeneric sentences. Item analyses
yielded parallel results.
EXPERIMENT 2
Experiment 2 investigated whether N400 amplitude is sensitive to the distinct
semantic processes involved in interpreting a word as characterising a kind
versus an instance of a kind and if the effect of genericity can be
distinguished from that of predictability.
Materials and Methods
Participants. Twenty-eight adults (11 females) participated. All partici-
pants (age range 19�34) were right-handed speakers of American English,
had normal or corrected-to-normal vision, and had no neurological
abnormalities. Data from 8 participants were excluded due to excessiveeye-movements.
Stimuli. The 40 sets of sentences from Experiment 1 were used. The
critical word, e.g., yellow or green, was marked in the EEG file for selective
averaging. The ratio of distracter to target sentences was �1.5:1. Distracters
were approximately matched in length to the target sentences and were
derived from an unrelated experiment on eventive/stative verbs.
Procedure. Sentences were presented in RSVP mode with an SOA of 300
ms and a duration of 300 ms/word. At the end of each trial, participants
initiated the next trial by button-press. Targets and distracters were
pseudorandomly interleaved. Participants’ task was to read the sentences.
Electrophysiological responses were recorded using Synamps Neuroscan
amplifiers and a 32-channel Electrocap fitted with sintered Ag/AgCl
electrodes (modified 10�20 electrode configuration). Data were recorded
232 PRASADA ET AL.
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continuously, in AC mode, using a mastoid reference (sampling rate 1000 Hz,
recording bandwidth 0.15�100 Hz). Impedances were below 5 kOhm for each
electrode.
Analysis. After manual artifact rejection, data were epoched around the
critical words (100 ms pre- to 700 ms post-stimulus), baseline corrected
(using the pre-stimulus interval), and averaged by condition within each
subject. For statistical analysis, ERPs were quantified as mean amplitude
during the selected time bin (300�500 ms), and six channels were selected:
three for which the amplitude of the N400 is typically modulated by
semantic factors (Pz, P3, P4; Group 1), and three for which it is not (Fz,
F3, F4; Group 2). Because this experiment is a hypothesis-testing study and
not a topographic brain-mapping study, we restricted the statistical analysis
to those channels known both from the literature and from visual
inspection of our data to yield robust N400 effects. Given that the design
predicts only subtle N400 contrasts across conditions due to their close
matching and similarity, we selected centro-parietal channels to probe for
the effect of genericity and frontal channels as controls. The 300�500 ms
time window was chosen on the basis of visual inspection of our response
profile and because it is the most common interval used in the N400
literature. Mean amplitudes were entered into a repeated measures 2�2�2
ANOVA with the factors of genericity, characteristicness, and electrode
group. For all analyses, Greenhouse�Geisser corrected values are reported.
For visualisation purposes, electrophysiological data are shown low-passed
filtered at 7 Hz.
Results
Figure 1 shows the electrode layout (four conditions overlaid) and highlights
the robust N400 effect. The differentiation among conditions is most obvious
along centro-parietal midline electrodes, consistent with standard N400
findings. Figure 2 shows the canonical N400 channel (Pz) with all four
conditions. During the N400 time window, the two generic conditions (red,
black) show a greater negativity than the corresponding nongenerics (blue,
green). Moreover, uncharacteristic sentences generally displayed greater
negativity than characteristic sentences, consistent with standard assump-
tions about predictability.
The ANOVA revealed a significant effect of genericity, F(1, 19)�8.267,
pB.01, and an interaction between genericity and electrode group,
F(1, 19)�4.508, pB.05. This interaction was due to there being a
significantly higher N400 response to generic than nongeneric sentences in
GENERICITY AND THE N400 233
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electrode group 1, F(1, 19)�13.982, pB.001, but no difference between the
two conditions in electrode group 2 (FB1).
Subsequent analyses showed that the difference between generic and
nongeneric sentences held for both uncharacteristic properties (grass is brown
versus the grass is brown, comparison1) and characteristic properties (grass is
green versus the grass is green, comparison2) at each of the electrodes in
group 1. Pz, comparison1, F(1, 19)�13.32, pB.001; comparison2, F(1,
19)�6.74, pB.014; P3, comparison1, F(1, 19)�10.31, pB.003; compar-
ison2, F(1, 19)�10.14, pB.003; P4, comparison1, F(1, 19)�7.28, pB.012;
comparison2, F(1, 19)�7.112, pB.013.
Planned contrasts were conducted comparing characteristic versus
uncharacteristic properties for both the generic and nongeneric conditions
at each of the electrodes in group 1. Whereas the mean N400 amplitude for
uncharacteristic properties was always numerically greater than that of
characteristic properties, the differences were not statistically significant or
were only marginally so.
Figure 1. Recording layout showing all channels, with the four critical conditions overlayed. A
robust N400 response is visible across the centro-parietal channels. A differentiation across
conditions is most clear along midline electrodes.
colo
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GENERAL DISCUSSION
The results demonstrate that N400 amplitude is sensitive to semantic
processes involved in interpreting a critical word as characterising a kind
rather than an instance of a kind. A significantly larger N400 was found
when a critical word characterised a kind than when that same word
characterised an instance of that kind. Furthermore, critical words in the
generic-characteristic condition (Bananas are yellow) elicited a larger N400
response than the same words in the nongeneric-characteristic condition
(The banana is yellow), even though the critical words were equally or more
predictable in the former condition, and were not anomalous in any way.
This result suggests that N400 amplitude is sensitive to the type of semantic
relation into which a critical word enters.
It is unlikely that the difference in sentence position can explain differences
between the N400 amplitude to the critical word in generic and nongeneric
conditions. Whereas it has been found that words later in a sentence generally
elicit smaller N400 responses, this result is usually interpreted as reflecting
additional constraints that are imposed on words later in the sentence, thus
making them more predictable (Kutas, Van Petten, & Besson, 1988; Van
Petten, 1995). However, as confirmed by Experiment 1B, when the critical
word refers to a characteristic property, it is less predictable in nongeneric
than in generic sentences, even though it appears later in nongeneric
sentences. Despite this, the characteristic critical words elicited greater
Figure 2. ERP waveforms at electrode Pz for the four conditions of interest. The critical word
appeared at 0 ms. There was an effect of condition in the N400 time window (300�500 ms). The
two generic conditions (red � uncharacteristic, black � characteristic) show a stronger N400
response than the two nongeneric conditions (green � uncharacteristic, blue � characteristic).
Moreover, the uncharacteristic conditions are associated with larger negativity.
colo
GENERICITY AND THE N400 235
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N400 responses in the generic sentences, and thus this N400 effect is unlikely
to be due to predictability effects arising from sentence position.
The interpretation of sentences that characterise kinds differs from that of
sentences that characterise instances of kinds in a number of ways. It is
unclear which of these differences is reflected in the N400 amplitude. The
fact that both true and false generic sentences elicited an increased N400 in
comparison to their corresponding nongeneric sentences suggests that the
effect is not tied to a specific truth-value (see Fischler et al., 1983 for similar
findings).
It can be argued that generic characteristic sentences (3) express aspects of
the representation of concepts within semantic memory and that their truth
is verified by reference to those concepts (Prasada, 2000). In contrast,
nongeneric sentences must be evaluated with respect to discourse representa-
tions and extra-linguistic context. Previous research suggests that N400
amplitude is sensitive to the structure of semantic memory (Federmeier &
Kutas, 1999; Fischler et al., 1983; Kounis & Holcomb, 1992). Thus, the effect
of genericity found in the present experiment may reflect the differential
involvement of semantic memory in the interpretation of generic and
nongeneric sentences.
Finally, differences in N400 amplitudes to generic and nongeneric
sentences may reflect the fact that the generic sentences expressed a principled
connection between the subject and the characterising word, whereas the
nongeneric sentences expressed a factual connection. If so, one might expect
statistical generics such as barns are red, which express factual connections
(Prasada & Dillingham, 2006), to be distinguished in their N400 response
from principled generics such as (3) in the same manner as nongenerics such
as (4). We are currently investigating this possibility.
Given the large number of studies that have found both effects of
predictability and plausibility on N400 amplitude (e.g., Federmeier & Kutas,
1999; Friederici et al., 1993; Hagoort & Brown, 1994; Kutas & Hillyard,
1980, 1984; Osterhout & Mobley, 1995; van Berkum et al., 1999; Van Petten,
1993, 1995), the lack of a reliable N400 effect of predictability/plausibility
was unexpected.6 However, the critical words used in the current study differ
from previous stimuli in theoretically important ways. For example, in the
present study, the unexpected words named values on the same dimension as
the expected words, and thus were semantically related to the expected word.
Previous research shows that semantic relatedness diminishes N400 ampli-
tude (Federmeier & Kutas, 1999).
6 Because the present experiment did not explicitly distinguish predictability and plausibility
we refer to their effect ambiguously, though we recognise that the two effects can be
distinguished (e.g., Federmeier & Kutas, 1999).
236 PRASADA ET AL.
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CONCLUSIONS
The capacity to talk about kinds as well as instances of kinds is a
fundamental aspect of semantic competence that develops at a very early
age (Gelman, 2003). The present study suggests that N400 amplitude is
sensitive to some of the semantic processes that distinguish interpreting a
word as characterising a kind as opposed to an instance of a kind, and thus
to the type of semantic relation into which a word enters. Given that the
generic and nongeneric sentences had identical content words, the resultssuggest that N400 amplitude is sensitive to interpretational differences that
are morphosyntactically signalled.
Although we do not know which difference between the interpretation of
generic and nongeneric sentences is reflected by N400 amplitude, there are
explicit proposals about the dimensions along which the interpretation of
such pairs of generic and nongeneric sentences differ (Carlson & Pelletier,
1995). Thus, it will be possible for future research to refine our under-
standing of this effect in a systematic and theoretically motivated manner.
Manuscript received September 2006
Revised manuscript received March 2007
First published online October 2007
REFERENCES
Carlson, G. N., & Pelletier, F. J. (1995). The generic book. Chicago, IL: Chicago University Press.
Federmeier, K. D., & Kutas, M. (1999). A rose by any other name: Long-term memory structure
and sentence processing. Journal of Memory and Language, 41, 469�495.
Fischler, I., Bloom, P. A., Childers, D. G., Roucos, S. E., & Perry, N. W. Jr. (1983). Brain potentials
related to stages of sentence verification. Psychophysiology, 20, 400�409.
Friederici, A. D., Pfeiffer, E., & Hahne, A. (1993). Event-related brain potentials during natural
speech processing: Effects of semantic, morphological and syntactic violations. Cognitive Brain
Research, 1, 183�192.
Gelman, S. A. (2003). The essential child. New York: Oxford University Press.
Hagoort, P., & Brown, C. M. (1994). Brain responses to lexical ambiguity resolution and parsing.
In C. Clifton Jr., L. Frazier, & K. Rayner (Eds.), Perspectives on sentence processing (pp. 45�80).
Hillsdale, NJ: Lawrence Erlbaum Associates.
Holcomb, P. J., Kounios, J., Anderson, J. E., & West, W. C. (1999). Dual-coding, context-availablity,
and concreteness effects in sentence comprehension: An electrophysiological investigation.
Journal or Experimental Psychology: Learning, Memory, and Cognition, 25, 721�742.
Kounis, J., & Holcomb, P. J. (1992). Structure and process in semantic memory: Evidence from
event-related brain potentials and reaction times. Journal of Experimental Psychology: General,
121, 459�479.
Krifka, M., Pelletier, F. J., Carlson, G. N., ter Meulen, A., Link, G., & Chierchia, G. (1995).
Genericity: An introduction. In G. N. Carlson & F. J. Pelletier (Eds.), The generic book.
Chicago, IL: University of Chicago Press.
Kutas, M. (1993). In the company of other words: Electrophysiological evidence for single-word
and sentence context effects. Language and Cognitive Processes, 8, 533�572.
GENERICITY AND THE N400 237
Dow
nloa
ded
by [
Way
ne S
tate
Uni
vers
ity]
at 1
9:14
26
Nov
embe
r 20
14
Kutas, M., & Hillyard, S. A. (1980). Reading senseless sentences: Brain potentials reflect semantic
incongruity. Science, 207, 203�205.
Kutas, M., & Hillyard, S. A. (1984). Brain potentials during reading reflect word expectancy and
semantic association. Nature, 307, 161�163.
Kutas, M., Van Petten, C. K., & Besson, M. (1988). Event-related potentials asymmetries during
the reading of sentences. Electroencephalography and Clinical Neurophysiology, 69, 218�233.
Neville, H., Nicol, J. L., Barss, A., Forster, K. I., & Garrett, M. F. (1991). Syntactically based
sentence processing classes: Evidence from event-related brain potentials. Journal of Cognitive
Neuroscience, 3, 151�165.
Osterhout, L., & Mobley, L. A. (1995). Event-related brain potentials elicited by failure to agree.
Journal of Memory and Language, 34, 739�773.
Prasada, S. (2000). Acquiring generic knowledge. Trends in Cognitive Sciences, 4, 66�72.
Prasada, S., & Dillingham, E. M. (2006). Principled and statistical connections in common sense
conception. Cognition, 99, 73�112.
Van Berkum, J. J. A., Hagoort, P., & Brown, C. M. (1999). Semantic integration in sentences and
discourse: Evidence from the N400. Journal of Cognitive Neuroscience, 11, 657�671.
Van Petten, C. (1993). A comparison of lexical and sentence-level context effects in event-related
potentials. Language and Cognitive Processes, 8, 485�531.
Van Petten, C. (1995). Words and sentences: Event-related brain potential measures. Psychophy-
siology, 32, 511�525.
Appendix A
Generic sentences Nongeneric sentences
Grass is green. The grass is green.
Grass is brown. The grass is brown.
Snow is white. The snow is white.
Snow is yellow. The snow is yellow.
Jalapenos are hot. The jalapeno is hot.
Jalapenos are mild. The jalapeno is mild.
Fire is hot. The fire is hot.
Fire is cold. The fire is cold.
Whales are big. This whale is big.
Whales are small. This whale is small.
Lemons are sour. This lemon is sour.
Lemons are bland. This lemon is bland.
Diamonds are expensive. This diamond is expensive.
Diamonds are cheap. This diamond is cheap.
Sirens are loud. This siren is loud.
Sirens are quiet (soft). This siren is quiet (soft).
Rocks are hard. This rock is hard.
Rocks are soft. This rock is soft.
Monsters are scary. This monster is scary.
Monsters are friendly. This monster is friendly.
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APPENDIX (Continued)
Generic sentences Nongeneric sentences
Feathers are light. This feather is light.
Feathers are heavy. This feather is heavy.
Knives are sharp. This knife is sharp.
Knives are dull. This knife is dull.
Spinach is green. This spinach is green.
Spinach is brown. This spinach is brown.
Apples are healthy. This apple is healthy.
Apples are poisonous. This apple is poisonous.
Games are fun. This game is fun.
Games are dangerous. This game is dangerous.
Bananas are yellow. This banana is yellow.
Bananas are green. This banana is green.
Dirt is brown. This dirt is brown.
Dirt is red. This dirt is red.
Pretzels are salty. This pretzel is salty.
Pretzels are sour. This pretzel is sour.
Winters are cold. This winter was cold.
Winters are warm. This winter was warm.
Elephants are big. This elephant is big.
Elephants are small. This elephant is small.
Cookies are sweet. This cookie is sweet.
Cookies are salty. This cookie is salty.
Cats are furry. This cat is furry.
Cats are hairless. This cat is hairless.
Cheetahs are fast. This cheetah is fast.
Cheetahs are slow. This cheetah is slow.
Oatmeal is mushy. This oatmeal is mushy.
Oatmeal is hard. This oatmeal is hard.
Angels are good. This angel is good.
Angels are bad. This angel is bad.
Dancers are graceful. This dancer is graceful.
Dancers are clumsy. This dancer is clumsy.
Needles are sharp. This needle is sharp.
Needles are dull. This needle is dull.
Strawberries are red. This strawberry is red.
Strawberries are green. This strawberry is green.
Mothers are caring. This mother is caring.
Mothers are selfish. This mother is selfish.
APPENDIX (Continued)
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APPENDIX (Continued)
Generic sentences Nongeneric sentences
Balls are round. This ball is round.
Balls are oval. This ball is oval.
Carrots are crunchy. This carrot is crunchy.
Carrots are soggy. This carrot is soggy.
Champagne is bubbly. This champagne is bubbly.
Champagne is flat. This champagne is flat.
Clowns are funny. This clown is funny.
Clowns are sad. This clown is sad.
Lions are carnivorous. This lion is carnivorous.
Lions are vegetarian. This lion is vegetarian.
Vinegar is sour. This vinegar is sour.
Vinegar is sweet. This vinegar is sweet.
Athletes are fit. This athlete is fit.
Athletes are fat. This athlete is fat.
Birds can fly. This bird can fly.
Birds can swim. This bird can swim.
Cherries are red. This cherry is red.
Cherries are brown. This cherry is brown.
Silver is shiny. This silver is shiny.
Silver is dull. This silver is dull.
Sponges are soft. This sponge is soft.
Sponges are hard. This sponge is hard.
APPENDIX (Continued)
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