Imageability and distributional typicality measures of nouns and verbs in contemporary English

Dissociations between noun and verb processing are not uncommon after brain injury; yet, precise psycholinguistic comparisons of nouns and verbs are hampered by the underrepresentation of verbs in published semantic word norms and by the absence of contemporary estimates for part-of-speech usage. We report herein imageability ratings and rating response times (RTs) for 1,197 words previously categorized as pure nouns, pure verbs, or words of balanced noun-verb usage on the basis of the Francis and Ku?era (1982) norms. Nouns and verbs differed in rated imageability, and there was a stronger correspondence between imageability rating and RT for nouns than for verbs. For all word types, the image-rating-RT function implied that subjects employed an image generation process to assign ratings. We also report a new measure of noun-verbtypicality that used the Hyperspace Analog to Language (HAL; Lund & Burgess, 1996) context vectors (derived from a large sample of Usenet text) to compute the mean context distance between each word and all of thepure nouns andpure verbs. For a subset of the items, the resulting HAL noun-verb difference score was compared with part-of-speech usage in a representative sample of the Usenet corpus. It is concluded that this score can be used to estimate the extent to which a given word occurs in typical noun or verb sentence contexts in informal contemporary English discourse. The item statistics given in Appendix B will enable experimenters to select representative examples of nouns and verbs or to compare typical with atypical nouns (or verbs), while holding constant or covarying rated imageability.     

Neuroanatomically separable effects of imageability and grammatical class during single-word comprehension

The present study characterizes the neural correlates of noun and verb imageability and addresses the question of whether components of the neural network supporting word recognition can be separately modified by variations in grammatical class and imageability. We examined the effect of imageability on BOLD signal during single-word comprehension of nouns and verbs. Subjects made semantic similarity judgments while undergoing functional magnetic resonance imaging (fMRI). Nouns and verbs were matched on imageability, and imageability varied continuously within a grammatical category. We observed three anatomically separable effects: a main effect of grammatical class, a main effect of imageability, and an imageability by grammatical class cross-over interaction. The left superior parietal lobule and a region in the left fusiform responded similarly to increases in noun and verb imageability; the left superior temporal gyrus showed greater activity for verbs than nouns after imageability was matched across grammatical class; and, in both the left middle temporal gyrus and the left inferior frontal lobe, a decrease in noun but not verb imageability resulted in higher BOLD signal. The presence of reliable and anatomically separable main effects of both imageability and grammatical class renders unlikely the hypothesis that previously reported dissociations between nouns and verbs can be dismissed as imageability effects. However, some regions previously thought to respond to grammatical class or imageability instead respond to the interaction of these variables.     

Verb-noun double dissociation in aphasic lexical impairments: the role of word frequency and imageability

Neurolinguistic studies have provided important evidence regarding the organization of lexical representations and the structure of underlying conceptual knowledge; in particular, it has been shown that the retrieval of verbs and nouns can be damaged selectively. Dissociated lexical damage is proof of an independent mental organization of lexical representations and/or of the underlying processes. The aim of the present study is to estimate the rate of dissociated impairments for nouns and verbs on a large sample of mild to moderate aphasic patients and to investigate the mechanisms underlying such phenomena. In addition, the authors wished to verify to what degree the impairment for nouns and verbs is related to a specific type of language disorder. A confrontation naming task for verbs and nouns was administered to 58 aphasic patients. The major lexical (word frequency and age of acquisition) and semantic variables (familiarity and imageability of the underlying concept) were considered for each noun and verb used in the task. Verbs were distinguished by major functional classes (transitive, intransitive, and ergative verbs). The data collected from this task were analyzed twice: (i) as a group study comparison of major aphasic subgroups and (ii) as a multiple single case study to evaluate the differences on the naming of verbs and nouns and the effect of the lexical semantic variables on each individual patient. The results confirm the existence of dissociated naming impairments of verbs and nouns. Selective impairment of verbs is more frequent (34%) than that of nouns (10%). In many cases, the dissociated pattern of naming impairment disappeared when the effect of the concomitant variables (word frequency and imageability) was removed, but in approximately one-fifth of the cases the noun or verb superiority was preserved. Noun superiority emerged in five of six agrammatic patients. Both the naming of verbs (n = 9) or of nouns (n = 6) could be impaired selectively in fluent aphasic patients. The results lend support to the hypothesis of an independent mental organization of nouns and verbs, but a substantial effect of imageability and word frequency suggests an interaction of the naming impairment with underlying lexical and semantic aspects.     

An image is worth a thousand words: why nouns tend to dominate verbs in early word learning

Nouns are generally easier to learn than verbs (e.g., Bornstein, 2005; Bornstein et al., 2004; Gentner, 1982; Maguire, Hirsh-Pasek, & Golinkoff, 2006). Yet, verbs appear in children's earliest vocabularies, creating a seeming paradox. This paper examines one hypothesis about the difference between noun and verb acquisition. Perhaps the advantage nouns have is not a function of grammatical form class but rather related to a word's imageability. Here, word imageability ratings and form class (nouns and verbs) were correlated with age of acquisition according to the MacArthur-Bates Communicative Development Inventory (CDI) (Fenson et al., 1994). CDI age of acquisition was negatively correlated with words' imageability ratings. Further, a word's imageability contributes to the variance of the word's age of acquisition above and beyond form class, suggesting that at the beginning of word learning, imageability might be a driving factor.     

Processing of English inflectional morphology

The present paper explores the representation of inflectional morphology in the English lexicon. There has been a long-standing debate about how these inflectional relationships might be involved during on-line processing. Inflected forms may be derived from an uninflected base form by rule application; by contrast, both regular and irregular inflection may be treated in the same way, with morphological patterns emerging from mappings between base and inflected forms. The present series of experiments investigated these issues using a lexical decision task. The first experiment showed that response latencies to nouns were significantly shorter than those to verbs. A possible explanation for these results can be found in differences in inflectional structure between English nouns and verbs. Namely, the relative frequency of uninflected compared with inflected forms is greater for nouns than for verbs. Two additional experiments compared noun stimuli with different inflectional structures. In all cases, differences in response latencies were predicted by the frequency of the surface form, whether uninflected or inflected. The pattern of results lends support for a unitary associative system for processing regular inflection of nouns in English and argues against the view that regular inflected plurals are derived by rule from a single, uninflected lexical entry.     

Comparing Nouns and Verbs in a Lexical Task

We analyzed the differential processing of nouns and verbs in a lexical decision task. Moderate and high-frequency nouns and verbs were compared. The characteristics of our material were specified at the formal level (number of letters and syllables, number of homographs, orthographic neighbors, frequency and age of acquisition), and at the semantic level (imagery, number and strength of associations, number of meanings, context dependency). A regression analysis indicated a classical frequency effect and a word-type effect, with latencies for verbs being slower than for nouns. The regression analysis did not permit the conclusion that semantic effects were involved (particularly imageability). Nevertheless, the semantic opposition between nouns as prototypical representations of objects, and verbs as prototypical representation of actions was not tested in this experiment and remains a good candidate explanation of the response time discrepancies between verbs and nouns.     

A Connectionist Model of English Past Tense and Plural Morphology

The acquisition of English noun and verb morphology is modeled using a single-system connectionist network. The network is trained to produce the plurals and past tense forms of a large corpus of monosyllabic English nouns and verbs. The developmental trajectory of network performance is analyzed in detail and is shown to mimic a number of important features of the acquisition of English noun and verb morphology in young children. These include an initial error-free period of performance on both nouns and verbs followed by a period of intermittent over-regularization of irregular nouns and verbs. Errors in the model show evidence of phonological conditioning and frequency effects. Furthermore, the network demonstrates a strong tendency to regularize denominal verbs and deverbal nouns and masters the principles of voicing assimilation. Despite their incorporation into a single-system network, nouns and verbs exhibit some important differences in their profiles of acquisition. Most importantly, noun inflections are acquired earlier than verb inflections. The simulations generate several empirical predictions that can be used to evaluate further the suitability of this type of cognitive architecture in the domain of inflectional morphology.     

Age of acquisition and imageability ratings for a large set of words, including verbs and function words

Age of acquisition and imageability ratings were collected for 2,645 words, including 892 verbs and 213 function words. Words that were ambiguous as to grammatical category were disambiguated: Verbs were shown in their infinitival form, and nouns (where appropriate) were preceded by the indefinite article (such asto crack anda crack). Subjects were speakers of British English selected from a wide age range, so that differences in the responses across age groups could be compared. Within the subset of early acquired noun/verb homonyms, the verb forms were rated as later acquired than the nouns, and the verb homonyms of high-image ability nouns were rated as significantly less imageable than their noun counterparts. A small number of words received significantly earlier or later age of acquisition ratings when the 20–40 years and 50–80 years age groups were compared. These tend to comprise words that have come to be used more frequently in recent years (either through technological advances or social change), or those that have fallen out of common usage. Regression analyses showed that although word length, familiarity, and concreteness make independent contributions to the age of acquisition measure, frequency and imageability are the most important predictors of rated age of acquisition.     

Semantic context influences memory for verbs more than memory for nouns

Three experiments revealed that memory for verbs is more dependent on semantic context than is memory for nouns. The participants in Experiment 1 were asked to remember either nouns or verbs from intransitive sentences. A recognition test included verbatim sentences, sentences with an old noun and a new verb, sentences with an old verb and a new noun, and entirely new sentences. Memory for verbs was significantly better when the verb was presented with the same noun at encoding and at retrieval. This contextual effect was much smaller for nouns. Experiments 2 and 3 replicated this effect and provided evidence that context effects reflect facilitation from bringing to mind the same meaning of a verb at encoding and at retrieval. Memory for verbs may be more dependent on semantic context because the meanings of verbs are more variable across semantic contexts than are the meanings of nouns.     

Different time courses of integrative semantic processing for plural and singular nouns: implications for theories of sentence processing

The research investigated the time course of integrative semantic processing during sentence processing. Reading time was measured on sentences containing an NP composed of an adjective and a noun whose combined meaning was plausible or anomalous (Experiment 1) or was typical or atypical (Experiment 2). The noun in the NP was either plural or singular. Plural nouns were expected to be more rapidly integrated with a preceding adjective than singular nouns because plural nouns can be ruled out as the first noun in a noun compound more rapidly than singular nouns. The results confirmed this prediction, showing that the effects of semantic plausibility and typicality were observed immediately during the processing of plural nouns, but were observed at a delay following the processing of singular nouns. Implications for theories of sentence processing are discussed.     

The influence of age of acquisition,root frequency,and context availability in processing nouns and verbs

In the Italian language there is a higher number of inflectional suffixes in verbs than in nouns, and this might imply that verbs are more likely to undergo a morphological analysis in terms of root and suffix as compared to nouns (Traficante & Burani, unpublished observations). Moreover, verbs tend to be more abstract than nouns, and this aspect might make verb processing more difficult. Finally, the developmental gap in the production of nouns and verbs suggests that age of acquisition might affect noun and verbs differently. Nouns and verbs were presented in a lexical decision and in a naming task. The morphological variable root frequency in addition to word frequency, length and word age of acquisition, and the semantic variables concreteness and context availability (Schwanenflugel, Harnishfeger, & Stowe, 1988) were used as predictors in multiple-regression analyses in which lexical decision and naming latencies were the dependent variables. The results showed that age of acquisition, context availability, and root frequency are all important in predicting both lexical decision and naming latencies for nouns and verbs, but age of acquisition and root frequency are better predictors of the differences in processing Italian nouns and verbs.     

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.     

Sometimes a noun is just a noun: comments on Bird, Howard, and Franklin (2000)

Bird, Howard, and Franklin (2000) have proposed a semantic-conceptual explanation of grammatical category-specific deficits that attributes impairments in noun and verb processing to two distinct mechanisms. According to their account, apparent deficits in verb production are not category specific, but rather result from the lower imageability of verbs compared to concrete nouns. Noun deficits are said to result from differences in the distribution of semantic feature types such that damage to sensory features results in disproportionate impairments in naming nouns, especially animate nouns, compared to verbs. However, this hypothesis, which we call the "extended sensory/functional theory" (ESFT), fails on several counts. First, the assumption that representations of living things are more heavily freighted with sensory features than are those of nonliving objects does not have any reliable empirical basis. Second, the ESFT incorrectly predicts associations between deficits in processing sensory features and living things or functional features and nonliving things. Finally, there are numerous cases of patients with grammatical category-specific deficits that do not seem to be consistent with damage at the semantic level. All of this suggests that the ESFT is not a useful model for considering grammatical (or semantic) category-specific deficits.     

The role of meaning in past-tense inflection: evidence from polysemy and denominal derivation

Although English verbs can be either regular (walk-walked) or irregular (sing-sang), "denominal verbs" that are derived from nouns, such as the use of the verb ring derived from the noun a ring, take the regular form even if they are homophonous with an existing irregular verb: The soldiers ringed the city rather than *The soldiers rang the city. Is this regularization due to a semantic difference from the usual verb, or is it due to the application of the default rule, namely VERB+ -ed suffix? In Experiment 1, participants rated the semantic similarity of the extended senses of polysemous verbs and denominal verbs to their central senses. Experiment 2 examined the acceptability of the regular and irregular past tenses of the different verbs. The results showed that all the denominal verbs were rated as more acceptable for the regular inflection than the same verbs used polysemously, even though the two were semantically equally similar to the central meaning. Thus, the derivation of the verb (nominal or verbal) determined the past-tense preference more than semantic variables, consistent with dual-route models of verb inflection.     

身体部位与早期习得的汉语动词的联结及其对动词习得年龄的影响

在英语等语言中, 动词习得被认为比名词习得更困难, 而汉语儿童在3岁以前却习得了大量动词, 仅表现出微弱的“名词优势”。Ma, Golinkoff, Hirsh-Pasek, McDonough和Tardif (2009)发现, 早期习得的汉语动词比英语动词具有更高的可表象性, 且可表象性可部分解释两种语言中动词习得年龄的变异。但是, 目前尚未有研究揭示汉语动词为何具有较高的可表象性。本研究假设, 早期动词与身体部位具有强烈的联结关系, 从而导致汉语动词具有较高的可表象性。研究1通过成人词汇联想任务, 考察了汉语儿童早期习得的169个行为动词与身体区域的联结关系。研究2请成人评定了这些动词的可表象性, 进一步考察动词-身体部位联结、可表象性和习得年龄之间的关系。研究结果验证了我们的假设。研究发现：1)汉语儿童早期习得的大部分动词都与特定身体区域有联结关系; 2)汉语儿童先习得关于手部区域(包括手和手臂)的动词, 其次是关于口部、腿部以及其他身体区域的动词; 3)动词联结的身体区域数可解释可表象性12%的变异; 4)动词-身体部位联结关系以可表象性为部分中介作用, 影响早期动词的习得年龄。研究结果表明, 汉语儿童早期习得动词与身体区域有较一致的联结关系, 且联结强度通过提高动词的可表象性而影响习得年龄。该结果对解释为何汉语儿童早期习得大量动词具有一定的启示作用。     

The dynamic influence of emotional words on sentence comprehension: An ERP study

In the present study, we explored the influence of emotional words on the semantic integration of their following neutral nouns during sentence comprehension. We manipulated the emotionality of verbs and the semantic congruity of their following (neutral) object nouns in sentences. Event-related potentials were recorded to the verbs, which were either negative or neutral, and to the object nouns, which were either semantically congruent or incongruent relative to the preceding contexts. We found an N400 and a P600 effect in response to the semantic congruity of the nouns when they followed the neutral verbs. However, the P600 (but not the N400) semantic congruity effect may have been attenuated when the nouns followed the negative verbs. Meanwhile, the negative verbs elicited a larger P2 and N400 than did the neutral verbs. The results indicate that the attention captured by emotional words impaired reanalysis of the following incongruent information, demonstrating a dynamic influence of emotional words on the semantic processing of following information during sentence comprehension.     

Semantic similarity and grammatical class in naming actions

Italian speakers were asked to name pictures of actions (e.g. "bere", to drink). Pictures were presented at the same time as distracter words that were semantically related or unrelated to the picture names, and were of the same or different grammatical class (verbs or nouns). Half of the participants named the actions as verbs in citation form, the other half as verbs inflected for third person singular or plural. We found a reliable semantic interference effect. Crucially, we also observed a significant interaction between naming context and grammatical class: naming latencies were slower for verb distracters in the inflected form condition, but not in the citation form condition. The results are taken to provide evidence for the separability of semantics and grammatical class.     

A common mechanism in verb and noun naming deficits in Alzheimer’s patients

We tested the ability of Alzheimer’s patients and elderly controls to name living and non-living nouns, and manner and instrument verbs. Patients’ error patterns and relative performance with different categories showed evidence of graceful degradation for both nouns and verbs, with particular domain-specific impairments for living nouns and instrument verbs. Our results support feature-based, semantic representations for nouns and verbs and support the role of inter-correlated features in noun impairment, and the role of noun knowledge in instrument verb impairment.     

Priming nouns and verbs: differential influences of semantic and grammatical cues in the two cerebral hemispheres

The current experiment investigated how sentential form-class expectancies influenced lexical-semantic priming within each hemisphere. Sentences were presented that led readers to expect a noun or a verb and the sentence-final target word was presented to one visual field/hemisphere for a lexical decision response. Noun and verb targets in the semantically related condition were compared to an unrelated prime condition, which also predicted part of speech but did not contain any lexical-semantic associates of the target word. The semantic priming effect was strongly modulated by form-class expectancy for RVF/LH targets, for both nouns and verbs. In the LVF/RH, semantic priming was obtained in all conditions, regardless of whether the form-class expectancy was violated. However, the nouns that were preceded by a noun-predicting sentence showed an extremely high priming value in the LVF/RH, suggesting that the RH may have some sensitivity to grammatical predictions for nouns. Comparisons of LVF/RH priming to calculations derived from the LSA model of language representation, which does not utilize word order, suggested that the RH might derive message-level meaning primarily from lexical-semantic relatedness.