Verb deficits in Alzheimer's disease and agrammatism: implications for lexical organization

This study examined the nature of verb deficits in 14 individuals with probable Alzheimer's Disease (PrAD) and nine with agrammatic aphasia. Production was tested, controlling both semantic and syntactic features of verbs, using noun and verb naming, sentence completion, and narrative tasks. Noun and verb comprehension and a grammaticality judgment task also were administered. Results showed that while both PrAD and agrammatic subjects showed impaired verb naming, the syntactic features of verbs (i.e., argument structure) influenced agrammatic, but not Alzheimer's disease patients' verb production ability. That is, agrammatic patients showed progressively greater difficulty with verbs associated with more arguments, as has been shown in previous studies (e.g., Kim & Thompson, 2000; Thompson, 2003; Thompson, Lange, Schneider, & Shapiro, 1997), and suggest a syntactic basis for verb production deficits in agrammatism. Conversely, the semantic complexity of verbs affected PrAD, but not agrammatic, patients' performance, suggesting "bottom-up" breakdown in their verb lexicon, paralleling that of nouns, resulting from the degradation or loss of semantic features of verbs.     

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.     

The Role of Semantic Features in Verb Processing

The present study examined the general hypothesis that, as for nouns, stable representations of semantic knowledge relative to situations expressed by verbs are available and accessible in long term memory in normal people. Regular associations between verbs and past tenses in French adults allowed to abstract two superordinate semantic features in the representation of verb meaning: durativity and resultativity. A pilot study was designed to select appropriate items according to these features: durative, non-resultative verbs and non-durative, resultative verbs. An experimental study was then conducted to assess semantic priming in French adults with two visual semantic-decision tasks at a 200- and 100-ms SOA. In the durativity decision task, participants had to decide if the target referred to a durable or non-durable situation. In the resultativity decision task, they had to decide if it referred to a situation with a directly observable outcome or without any clear external outcome. Targets were preceded by similar, opposite, and neutral primes. Results showed that semantic priming can tap verb meaning at a 200- and 100-ms SOA, with the restriction that only the positive value of each feature benefited from priming, that is the durative and resultative values. Moreover, processing of durativity and resultativity is far from comparable since facilitation was shown on the former with similar and opposite priming, whereas it was shown on the latter only with similar priming. Overall, these findings support Le Ny’s (in: Saint-Dizier, Viegas (eds) Computational lexical semantics, 1995; Cahier de Recherche Linguistique LanDisCo 12:85–100, 1998; Comment l’esprit produit du sens, 2005) general hypothesis that classificatory properties of verbs could be interpreted as semantic features and the view that semantic priming can tap verb meaning, as noun meaning.     

Usage frequencies of complement-taking verbs in Spanish and English: Data from Spanish monolinguals and Spanish—English bilinguals

Verb bias, or the tendency of a verb to appear with a certain type of complement, has been employed in psycholinguistic literature as a tool to test competing models of sentence processing. To date, the vast majority of sentence processing research involving verb bias has been conducted almost exclusively with monolingual speakers, and predominantly with monolingual English speakers, despite the fact that most of the world’s population is bilingual. To test the generality of competing theories of sentence comprehension, it is important to conduct cross-linguistic studies of sentence processing and to add bilingual data to theories of sentence comprehension. Given this, it is critical for the field to develop verb bias estimates from monolingual speakers of languages other than English and from bilingual populations. We begin to address these issues in two norming studies. Study 1 provides verb bias norming data for 135 Spanish verbs. A second aim of Study 1 was to determine whether verb bias estimates remain stable over time. In Study 2, we asked whether Spanish—English speakers are able to learn verb-specific information, such as verb bias, in their second language. The answer to this question is critical to conducting studies that examine when, during the course of sentence comprehension, bilingual speakers exploit verb information specific to the second language. To facilitate cross-linguistic work, we compared our verb bias results with those provided by monolingual English speakers in a previous norming study conducted by Garnsey, Lotocky, Pearlmutter, and Myers (1997). Our Spanish data demonstrated that individual verbs showed significant similarities in their verb bias across the 3 years of data collection. We also show that bilinguals are able to learn the biases of verbs in their second language, even when immersed in the first language environment. Appendixes A–C, containing the bilingual norms discussed in the article, may be downloaded from http://brm.psychonomic-journals.org/content/supplemental.     

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.     

Psycholinguistic measures for German verb pairs: Semantic transparency,semantic relatedness,verb family size,and age of reading acquisition

A central issue in visual and spoken word recognition is the lexical representation of complex words—in particular, whether the lexical representation of complex words depends on semantic transparency: Is a complex verb like understand lexically represented as a whole word or via its base stand, given that its meaning is not transparent from the meanings of its parts? To study this issue, a number of stimulus characteristics are of interest that are not yet available in public databases of German. This article provides semantic association ratings, lexical paraphrases, and vector-based similarity measures for German verbs, measuring (a) the semantic transparency between 1,259 complex verbs and their bases, (b) the semantic relatedness between 1,109 verb pairs with 432 different bases, and (c) the vector-based similarity measures of 846 verb pairs. Additionally, we include the verb regularity of all verbs and two counts of verb family size for 184 base verbs, as well as estimates of age of acquisition and age of reading for 200 verbs. Together with lemma and type frequencies from public lexical databases, all measures can be downloaded along with this article. Statistical analyses indicate that verb family size, morphological complexity, frequency, and verb regularity affect the semantic transparency and relatedness ratings as well as the age of acquisition estimates, indicating that these are relevant variables in psycholinguistic experiments. Although lexical paraphrases, vector-based similarity measures, and semantic association ratings may deliver complementary information, the interrater reliability of the semantic association ratings for each verb pair provides valuable information when selecting stimuli for psycholinguistic experiments.     

Verbs in space: Axis and direction of motion norms for 299 English verbs

A strong body of work has explored the interaction between visual perception and language comprehension; for example, recent studies exploring predictions from embodied cognition have focused particularly on the common representation of sensory—motor and semantic information. Motivated by this background, we provide a set of norms for the axis and direction of motion implied in 299 English verbs, collected from approximately 100 native speakers of British English. Until now, there have been no freely available norms of this kind for a large set of verbs that can be used in any area of language research investigating the semantic representation of motion. We have used these norms to investigate the interaction between language comprehension and low-level visual processes involved in motion perception, validating the norming procedure’s ability to capture the motion content of individual verbs. Supplemental materials for this study may be downloaded from brm.psychonomic-journals.org/content/supplemental.     

Interplay of emotional valence and concreteness in word processing: An event-related potential study with verbs

The functional locus of emotional valence in word processing remains an open question. In event-related potentials, emotion has been found to elicit an early posterior negativity (EPN), which is assumed to reflect attention catching by the words’ meaning. Previously, the EPN was modulated by word category with verbs exhibiting longer EPN latencies compared with other word categories. Here we examined whether concreteness, a semantic variable, influences emotion processing. Within a lexical decision task for verbs, emotional valence (positive, negative, and neutral) was orthogonally combined with concreteness (concrete and abstract). EPN onset was found already at 250 ms post-stimulus for concrete verbs, whereas it started 50 ms later for abstract verbs. Concreteness effects occurred after the start of main effects of emotion. Thus, the elicitation of the EPN seems to be based on semantic processes, with emotional valence being accessed before other semantic aspects such as concreteness of verbs.     

Une base de données en sémantique du verbe : Semasit

In this article, we present Semasit, a semantic database for French verbs developed for the purposes of experimental research in psycholinguistics and neuropsychology. This database features the distribution of the agents and patients of 96 verbs of interpersonal relations, and 60 verbs of change of state, based on their probability of occurence for 100 participants. It also provides the free-association norms of these 156 verbs. The degree of imagery is also presented for some of them. For 24 verbs of interpersonal relations, this semantic database is completed by the distribution of the patients, when an agent and a verb are presented together. It also provides the free association norms of the patients in this case. This database in freely accessible and can be downloaded from the Internet: http://www.mshs.univ-poitiers.fr/lmdc/semasit/frame-index.htm.     

Checking and bootstrapping lexical norms by means of word similarity indexes

In psychology, lexical norms related to the semantic properties of words, such as concreteness and valence, are important research resources. Collecting such norms by asking judges to rate the words is very time consuming, which strongly limits the number of words that compose them. In the present article, we present a technique for estimating lexical norms based on the latent semantic analysis of a corpus. The analyses conducted emphasize the technique??s effectiveness for several semantic dimensions. In addition to the extension of norms, this technique can be used to check human ratings to identify words for which the rating is very different from the corpus-based estimate.     

Verb Comprehension Deficits in Probable Alzheimer's Disease

Studies of lexical comprehension in probable Alzheimer's disease (pAD) have focused almost exclusively on nouns. In the following preliminary study, we examined whether lexical comprehension for verbs is also impaired in 25 pAD patients. The semantic meaning of motion verbs, cognition verbs, and perception verbs was assessed with a triadic comparison task. Structural meaning associated with these verbs was evaluated by asking the patients to judge the coherence of sentence frames that accept these verbs naturally or awkwardly. We found that pAD patients are significantly impaired at identifying semantic relations among verbs. pAD patients also encountered significantly more difficulty judging the coherence of sentences than control subjects. Correlation and regression analyses demonstrated that semantic characteristics of verbs are projected from the verbs' sentence frames in control subjects, but there was minimal evidence for such a structural–semantic relationship in pAD. We consider several possible explanations for our preliminary observations of an impairment that has consequences for processing both semantic and structural aspects of verb meaning.     

Event templates in the lexical representations of verbs

Four experiments support the hypothesis that syntactically relevant information about verbs is encoded in the lexicon in semantic event templates. A verb's event template represents the participants in an event described by the verb and the relations among the participants. The experiments show that lexical decision times are longer for verbs with more complex templates than verbs with less complex templates and that, for both transitive and intransitive sentences, sentences containing verbs with more complex templates take longer to process. In contrast, sentence processing times did not depend on the probabilities with which the verbs appear in transitive versus intransitive constructions in a large corpus of naturally produced sentences.     

Category norm data and relationships with lexical frequency and typicality within verb semantic categories

The aim of the present study was to expand the scope of category norm and typicality data to include verbs for use when investigating semantic memory in fields such as linguistics, psychology, and aphasiology. Two experiments were conducted. In the first, participants were asked to list verbs within 10 semantic categories (e.g. breaking, cleaning, cooking, etc.) and 10 noun categories (e.g. animals, fruit, tools, etc.). In the second experiment, participants were asked to rate the typicality of verbs within 8 of the previously investigated verb categories. Although participants listed fewer verbs in verb categories than nouns in noun categories, the overall patterns with regard to correlation analyses between production frequency, mean rank of responses, lexical frequency, and typicality were consistent with those observed in noun categories. These patterns are also consistent with those observed in previous research. Potential similarities and differences between nouns and verbs, as well as future applications of such data, are discussed.     

Selection demands versus association strength in the verb generation task

Neuroimaging and neuropsychological data from Thompson-Schill and colleagues (Thompson-Schill, D’Esposito, Aguirre, & Farah, 1997; Thompson-Schill et al., 1998) showed that in the verb generation task, the left inferior frontal gyrus (left IFG) was more involved in a high-selection condition, in which the noun had two verb responses of equal association strength, than in a low-selection condition, in which the noun had only one strongly associated verb. They proposed that the left IFG was involved in selecting semantic information from competing alternatives. The present study compared verb generation in two high-selection conditions that varied in the association strength of the most frequently produced verbs. The results from neurally intact participants and a patient with a lesion that included the left IFG indicated that association strength between nouns and the most frequently produced verb, rather than competition during verb selection, affected verb generation. The degree of involvement of the left IFG may depend on the difficulty of verb retrieval as reflected in association strength.     

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.     

The role of entrenchment in children’s and adults’ performance on grammaticality judgment tasks

Between the ages of 3 and 7 years, children have been observed to produce verb argument structure overgeneralization errors (e.g., Don’t giggle me; Bowerman, 1982, 1988; Pinker, 1989). A number of recent studies have begun to find evidence that the precise distributional properties of the input may provide an important part of the explanation for why children retreat from overgeneralization errors (Brooks & Tomasello, 1999; Brooks, Tomasello, Dodson, & Lewis, 1999). The current study evaluates the role of entrenchment (Braine & Brooks, 1995) in constraining argument structure overgeneralization errors using a grammaticality judgment task. The 5-year-olds, 8-year-olds, and adults were presented with examples of argument structure errors containing high and low frequency verbs matched for semantic class and asked to indicate whether, or the extent to which they found the sentences to be grammatical. The data show that across all groups, sentences with argument structure errors containing low frequency verbs were judged to be significantly more grammatical than those containing high frequency verbs. These findings provide further support for the entrenchment hypothesis and suggest that verb frequency plays an important and continuing role in determining a speaker’s choice of verb argument structure.     

The input to verb learning in Mandarin Chinese: a role for syntactic bootstrapping

The authors investigated the role of syntax in verb learning in Mandarin Chinese, which allows pervasive ellipsis of noun arguments. Two questions were investigated using the Beijing corpus on CHILDES: (a) Does the input to young children manifest syntactic-semantic correspondences as needed for acquiring verb meanings? (b) Are verbs presented in multiple frames? Over 6,000 child-directed utterances were parsed. Analyses revealed that transitive verbs, motion verbs, and internal/communication verbs were distinguished syntactically; moreover, the 60 target verbs were used in multiple sentence frames. These findings support a role for syntactic bootstrapping in Mandarin verb learning.     

Semantic weight and verb retrieval in aphasia

Individuals with agrammatic aphasia may have difficulty with verb production in comparison to nouns. Additionally, they may have greater difficulty producing verbs that have fewer semantic components (i.e., are semantically "light") compared to verbs that have greater semantic weight. A connectionist verb-production model proposed by Gordon and Dell (2003) learns through error correction to "divide the labor" between syntax and semantics. Verbs that are semantically heavier come to depend less on syntax and more on semantics. For lighter verbs, the reverse is true. We performed this study to clarify the role of semantic weight in aphasic verb production and to test the prediction from Gordon and Dell that a brain lesion that impairs the syntactic input to verb retrieval will impair lighter verbs more than heavier ones. Consistent with this prediction, we found that the decrement for lighter verbs was present in a group with agrammatic aphasia but not in a matched group without agrammatism.     

The influence of semantic and morphological complexity of verbs on sentence recall: Implications for the nature of conceptual representation and category-specific deficits

One hundred and forty normal undergraduate students participated in a Proactive Interference (PI) experiment with sentences containing verbs from four different semantic and morphological classes (lexical causatives, morphological causatives, and morphologically complex and simplex perception verbs). Past research has shown significant PI build-up effects for semantically and morphologically complex verbs in isolation (de Almeida & Mobayyen, 2004). The results of the present study show that, when embedded into sentence contexts, semantically and morphologically complex verbs do not produce significant PI build-up effects. Different verb classes, however, yield different recall patterns: sentences with semantically complex verbs (e.g., causatives) were recalled significantly better than sentences with semantically simplex verbs (e.g., perception verbs). The implications for the nature of both verb-conceptual representations and category-specific semantic deficits are discussed.     

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.