The neural representation of abstract words: the role of emotion.

It is generally assumed that abstract concepts are linguistically coded, in line with imaging evidence of greater engagement of the left perisylvian language network for abstract than concrete words (Binder JR, Desai RH, Graves WW, Conant LL. 2009. Where is the semantic system? A critical review and meta-analysis of 120 functional neuroimaging studies. Cerebral Cortex. 19:2767-2796; Wang J, Conder JA, Blitzer DN, Shinkareva SV. 2010. Neural representation of abstract and concrete concepts: A meta-analysis of neuroimaging studies. Hum Brain Map. 31:1459-1468). Recent behavioral work, which used tighter matching of items than previous studies, however, suggests that abstract concepts also entail affective processing to a greater extent than concrete concepts (Kousta S-T, Vigliocco G, Vinson DP, Andrews M, Del Campo E. The representation of abstract words: Why emotion matters. J Exp Psychol Gen. 140:14-34). Here we report a functional magnetic resonance imaging experiment that shows greater engagement of the rostral anterior cingulate cortex, an area associated with emotion processing (e.g., Etkin A, Egner T, Peraza DM, Kandel ER, Hirsch J. 2006. Resolving emotional conflict: A role for the rostral anterior cingulate cortex in modulating activity in the amygdala. Neuron. 52:871), in abstract processing. For abstract words, activation in this area was modulated by the hedonic valence (degree of positive or negative affective association) of our items. A correlation analysis of more than 1,400 English words further showed that abstract words, in general, receive higher ratings for affective associations (both valence and arousal) than concrete words, supporting the view that engagement of emotional processing is generally required for processing abstract words. We argue that these results support embodiment views of semantic representation, according to which, whereas concrete concepts are grounded in our sensory-motor experience, affective experience is crucial in the grounding of abstract concepts.

The road to language learning is iconic: evidence from British Sign Language.

An arbitrary link between linguistic form and meaning is generally considered a universal feature of language. However, iconic (i.e., nonarbitrary) mappings between properties of meaning and features of linguistic form are also widely present across languages, especially signed languages. Although recent research has shown a role for sign iconicity in language processing, research on the role of iconicity in sign-language development has been mixed. In this article, we present clear evidence that iconicity plays a role in sign-language acquisition for both the comprehension and production of signs. Signed languages were taken as a starting point because they tend to encode a higher degree of iconic form-meaning mappings in their lexicons than spoken languages do, but our findings are more broadly applicable: Specifically, we hypothesize that iconicity is fundamental to all languages (signed and spoken) and that it serves to bridge the gap between linguistic form and human experience.

The hands and mouth do not always slip together in British sign language: dissociating articulatory channels in the lexicon.

In contrast to the single-articulatory system of spoken languages, sign languages employ multiple articulators, including the hands and the mouth. We asked whether manual components and mouthing patterns of lexical signs share a semantic representation, and whether their relationship is affected by the differing language experience of deaf and hearing native signers. We used picture-naming tasks and word-translation tasks to assess whether the same semantic effects occur in manual production and mouthing production. Semantic errors on the hands were more common in the English-translation task than in the picture-naming task, but errors in mouthing patterns showed a different trend. We conclude that mouthing is represented and accessed through a largely separable channel, rather than being bundled with manual components in the sign lexicon. Results were comparable for deaf and hearing signers; differences in language experience did not play a role. These results provide novel insight into coordinating different modalities in language production.

The link between form and meaning in American Sign Language: lexical processing effects.

Signed languages exploit iconicity (the transparent relationship between meaning and form) to a greater extent than spoken languages. where it is largely limited to onomatopoeia. In a picture-sign matching experiment measuring reaction times, the authors examined the potential advantage of iconicity both for 1st- and 2nd-language learners of American Sign Language (ASL). The results show that native ASL signers are faster to respond when a specific property iconically represented in a sign is made salient in the corresponding picture, thus providing evidence that a closer mapping between meaning and form can aid in lexical retrieval. While late 2nd-language learners appear to use iconicity as an aid to learning sign (R. Campbell, P. Martin, & T. White, 1992), they did not show the same facilitation effect as native ASL signers, suggesting that the task tapped into more automatic language processes. Overall, the findings suggest that completely arbitrary mappings between meaning and form may not be more advantageous in language and that, rather, arbitrariness may simply be an accident of modality.

Investigating linguistic relativity through bilingualism: the case of grammatical gender.

The authors investigated linguistic relativity effects by examining the semantic effects of grammatical gender (present in Italian but absent in English) in fluent bilingual speakers as compared with monolingual speakers. In an error-induction experiment, they used responses by monolingual speakers to establish a baseline for bilingual speakers and show that gender affects the semantic substitution errors made by monolingual Italian speakers compared with monolingual English speakers. They then showed that Italian-English bilingual speakers behave like monolingual English speakers when the task is in English and like monolingual Italian speakers when the task is in Italian, hence exhibiting appropriate semantic representations for each language. These results show that for bilingual speakers there is intraspeaker relativity in semantic representations and, therefore, that gender does not have a conceptual, nonlinguistic effect. The results also have implications for models of bilingual semantic memory and processing.

Language and imagery: effects of language modality.

Across spoken languages, properties of wordforms (e.g. the sounds in the word hammer) do not generally evoke mental images associated to meanings. However, across signed languages, many signforms readily evoke mental images (e.g. the sign HAMMER resembles the motion involved in hammering). Here we assess the relationship between language and imagery, comparing the performance of English speakers and British sign language (BSL) signers in meaning similarity judgement tasks. In experiment 1, we found that BSL signers used these imagistic properties in making meaning similarity judgements, in contrast with English speakers. In experiment 2, we found that English speakers behaved more like BSL signers when asked to develop mental images for the words before performing the same task. These findings show that language differences can bias users to attend more to those aspects of the world encoded in their language than to those that are not; and that language modality (spoken versus signed) can affect the degree to which imagery is involved in language.

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.

Grammatical gender effects on cognition: implications for language learning and language use.

In 4 experiments, the authors addressed the mechanisms by which grammatical gender (in Italian and German) may come to affect meaning. In Experiments 1 (similarity judgments) and 2 (semantic substitution errors), the authors found Italian gender effects for animals but not for artifacts; Experiment 3 revealed no comparable effects in German. These results suggest that gender effects arise as a generalization from an established association between gender of nouns and sex of human referents, extending to nouns referring to sexuated entities. Across languages, such effects are found when the language allows for easy mapping between gender of nouns and sex of human referents (Italian) but not when the mapping is less transparent (German). A final experiment provided further constraints: These effects during processing arise at a lexical-semantic level rather than at a conceptual level.

Semantic distance effects on object and action naming.

Graded interference effects were tested in a naming task, in parallel for objects and actions. Participants named either object or action pictures presented in the context of other pictures (blocks) that were either semantically very similar, or somewhat semantically similar or semantically dissimilar. We found that naming latencies for both object and action words were modulated by the semantic similarity between the exemplars in each block, providing evidence in both domains of graded semantic effects.

Role of grammatical gender and semantics in German word production.

Semantic substitution errors (e.g., saying "arm" when "leg" is intended) are among the most common types of errors occurring during spontaneous speech. It has been shown that grammatical gender of German target nouns is preserved in the errors (E. Mane, 1999). In 3 experiments, the authors explored different accounts of the grammatical gender preservation effect in German. In all experiments, semantic substitution errors were induced using a continuous naming paradigm. In Experiment 1, it was found that gender preservation disappeared when speakers produced bare nouns. Gender preservation was found when speakers produced phrases with determiners marked for gender (Experiment 2) but not when the produced determiners were not marked for gender (Experiment 3). These results are discussed in the context of models of lexical retrieval during production.

The breakdown of semantic knowledge: insights from a statistical model of meaning representation.

Investigations of patients with semantic category-specific deficits have revealed a wide range of performance and variability in categories that are impaired or spared; this variability presents a challenge to accounts of category specificity. Accounts based only on impairment to semantic features of a particular type (e.g., visual), as well as accounts based only on featural properties (e.g., feature intercorrelations), are insufficient to explain the variability of patients' performance. A first goal of the paper is to discuss how a hybrid account incorporating both a level of organization according to feature types (a level of nonlinguistic conceptual representations) and a level of organization dictated by featural properties may provide a more comprehensive account of the cases reported in the literature. The second and most novel goal of the study reported here is to derive from our hybrid account a series of novel predictions concerning the representation and impairment of a different domain of knowledge: knowledge of actions and events, a domain of knowledge that has received remarkably little attention to date.

Nouns and verbs in the brain: a review of behavioural, electrophysiological, neuropsychological and imaging studies.

In the past 30 years there has been a growing body of research using different methods (behavioural, electrophysiological, neuropsychological, TMS and imaging studies) asking whether processing words from different grammatical classes (especially nouns and verbs) engage different neural systems. To date, however, each line of investigation has provided conflicting results. Here we present a review of this literature, showing that once we take into account the confounding in most studies between semantic distinctions (objects vs. actions) and grammatical distinction (nouns vs. verbs), and the conflation between studies concerned with mechanisms of single word processing and those studies concerned with sentence integration, the emerging picture is relatively clear-cut: clear neural separability is observed between the processing of object words (nouns) and action words (typically verbs), grammatical class effects emerge or become stronger for tasks and languages imposing greater processing demands. These findings indicate that grammatical class per se is not an organisational principle of knowledge in the brain; rather, all the findings we review are compatible with two general principles described by typological linguistics as underlying grammatical class membership across languages: semantic/pragmatic, and distributional cues in language that distinguish nouns from verbs. These two general principles are incorporated within an emergentist view which takes these constraints into account.

The representation of abstract words: why emotion matters.

Although much is known about the representation and processing of concrete concepts, knowledge of what abstract semantics might be is severely limited. In this article we first address the adequacy of the 2 dominant accounts (dual coding theory and the context availability model) put forward in order to explain representation and processing differences between concrete and abstract words. We find that neither proposal can account for experimental findings and that this is, at least partly, because abstract words are considered to be unrelated to experiential information in both of these accounts. We then address a particular type of experiential information, emotional content, and demonstrate that it plays a crucial role in the processing and representation of abstract concepts: Statistically, abstract words are more emotionally valenced than are concrete words, and this accounts for a residual latency advantage for abstract words, when variables such as imageability (a construct derived from dual coding theory) and rated context availability are held constant. We conclude with a discussion of our novel hypothesis for embodied abstract semantics.

The link between form and meaning in British sign language: effects of iconicity for phonological decisions.

Signed languages exploit the visual/gestural modality to create iconic expression across a wide range of basic conceptual structures in which the phonetic resources of the language are built up into an analogue of a mental image (Taub, 2001). Previously, we demonstrated a processing advantage when iconic properties of signs were made salient in a corresponding picture during a picture and sign matching task (Thompson, Vinson, & Vigliocco, 2009). The current study investigates the extent of iconicity effects with a phonological decision task (does the sign involve straight or curved fingers?) in which the meaning of the sign is irrelevant. The results show that iconicity is a significant predictor of response latencies and accuracy, with more iconic signs leading to slower responses and more errors. We conclude that meaning is activated automatically for highly iconic properties of a sign, and this leads to interference in making form-based decisions. Thus, the current study extends previous work by demonstrating that iconicity effects permeate the entire language system, arising automatically even when access to meaning is not needed.

Emotion words, regardless of polarity, have a processing advantage over neutral words.

Despite increasing interest in the interface between emotion and cognition, the role of emotion in cognitive tasks is unclear. According to one hypothesis, negative valence is more relevant for survival and is associated with a general slowdown of the processing of stimuli, due to a defense mechanism that freezes activity in the face of threat. According to a different hypothesis which does not posit a privileged role for the aversive system, valence, regardless of polarity, facilitates processing due to the relevance of both negative and positive stimuli for survival and for the attainment of goals. Here, we present evidence that emotional valence has an overall facilitatory role in the processing of verbal stimuli, providing support for the latter hypothesis. We found no asymmetry between negative and positive words and suggest that previous findings of such an asymmetry can be attributed to failure to control for a number of critical lexical variables and to a sampling bias.

Semantic feature production norms for a large set of objects and events.

Semantic features produced by speakers of a language when given a word corresponding to a concept have provided insight into numerous behavioral phenomena concerning semantic representation in language-impaired and -unimpaired speakers. A number of theories concerning the organization of semantic memory have used features as their starting point. Here, we provide a set of feature norms collected from approximately 280 participants for a total of 456 words (169 nouns referring to objects, 71 nouns referring to events, and 216 verbs referring to events). Whereas a number of feature norms for object concepts already exist, we provide the first set of norms for event concepts. We have used these norms (for both objects and events) in research addressing questions concerning the similarities and differences between the semantic representation of objects and events and in research concerning the interface between semantics and syntax, given that events can be expressed in language as nouns or verbs. Some of this research is summarized here. These norms may be downloaded from www.psychonomic.org/archive.

The British Sign Language (BSL) norms for age of acquisition, familiarity, and iconicity.

Research on signed languages offers the opportunity to address many important questions about language that it may not be possible to address via studies of spoken languages alone. Many such studies, however, are inherently limited, because there exist hardly any norms for lexical variables that have appeared to play important roles in spoken language processing. Here, we present a set of norms for age of acquisition, familiarity, and iconicity for 300 British Sign Language (BSL) signs, as rated by deaf signers, in the hope that they may prove useful to other researchers studying BSL and other signed languages. These norms may be downloaded from www.psychonomic.org/archive.

The role of grammatical class on word recognition.

The double dissociation between noun and verb processing, well documented in the neuropsychological literature, has not been supported in imaging studies. Recent imaging studies, in fact, suggest that once confounding with semantics is eliminated, grammatical class effects only emerge as a consequence of building frames. Here we assess this hypothesis behaviorally in two visual word recognition experiments. In Experiment 1, participants made lexical decisions on verb targets. We manipulated the grammatical class of the prime words (either nouns or verbs and always introduced in a minimal phrasal context, i.e., "the+N" or "to+V"), and their semantic similarity to a target (related vs. unrelated). We found reliable effects of grammatical class, and no interaction with semantic similarity. Experiment 2 further explored this grammatical class effect, using verb targets preceded by semantically unrelated verb vs. noun primes. In one condition, prime words were presented as bare words; in the other, they were presented in the minimal phrasal context used in Experiment 1. Grammatical class effects only arose in the latter but not in the former condition thus providing evidence that word recognition does not recruit grammatical class information unless it is provided to the system.

Representing the meanings of object and action words: the featural and unitary semantic space hypothesis.

This paper presents the Featural and Unitary Semantic Space (FUSS) hypothesis of the meanings of object and action words. The hypothesis, implemented in a statistical model, is based on the following assumptions: First, it is assumed that the meanings of words are grounded in conceptual featural representations, some of which are organized according to modality. Second, it is assumed that conceptual featural representations are bound into lexico-semantic representations that provide an interface between conceptual knowledge and other linguistic information (syntax and phonology). Finally, the FUSS model employs the same principles and tools for objects and actions, modeling both domains in a single semantic space. We assess the plausibility of the model by showing that it can capture generalizations presented in the literature, in particular those related to category-related deficits, and show that it can predict semantic effects in behavioral experiments for object and action words better than other models such as Latent Semantic Analysis (Landauer & Dumais, 1997) and similarity metrics derived from Wordnet (Miller & Fellbaum, 1991).