A close call: Interference from semantic neighbourhood density and similarity in language production.

The present study investigated how lexical selection is influenced by the number of semantically related representations (semantic neighbourhood density) and their similarity (semantic distance) to the target in a speeded picture-naming task. Semantic neighbourhood density and similarity as continuous variables were used to assess lexical selection for which competitive and noncompetitive mechanisms have been proposed. Previous studies found mixed effects of semantic neighbourhood variables, leaving this issue unresolved. Here, we demonstrate interference of semantic neighbourhood similarity with less accurate naming responses and a higher likelihood of producing semantic errors and omissions over accurate responses for words with semantically more similar (closer) neighbours. No main effect of semantic neighbourhood density and no interaction between semantic neighbourhood density and similarity was found. We assessed further whether semantic neighbourhood density can affect naming performance if semantic neighbours exceed a certain degree of semantic similarity. Semantic similarity between the target and each neighbour was used to split semantic neighbourhood density into two different density variables: The number of semantically close neighbours versus distant neighbours. The results showed a significant effect of close, but not of distant, semantic neighbourhood density: Naming pictures of targets with more close semantic neighbours led to longer naming latencies, less accurate responses, and a higher likelihood for the production of semantic errors and omissions over accurate responses. The results show that word inherent semantic attributes such as semantic neighbourhood similarity and the number of coactivated close semantic neighbours modulate lexical selection supporting theories of competitive lexical processing.

From "some butter" to "a butter": an investigation of mass and count representation and processing.

This paper investigates the representation of mass and count nouns at the lexical-syntactic level, an issue that has not been addressed to date in psycholinguistic theories. A single case study is reported of a man with aphasia, R.A.P., who showed a countability specific deficit that affected processing of mass noun grammar. R.A.P. frequently substituted mass noun determiners (e.g., some, much) with count noun determiners (e.g., a, many). Experimental investigations determined that R.A.P. had a modality-neutral lexical-syntactic impairment. Furthermore, a series of novel experiments revealed that R.A.P.'s processing of mass noun determiners varied depending on how mass nouns were depicted (single vs. multiple depictions) and how congruent these were with the conceptual-semantic information of target determiners (e.g., "some" corresponds to multiple but not single concepts). R.A.P.'s determiner difficulties emerged only when mass nouns and determiners were number incongruent. The results of this research clearly indicate that nouns are lexical-syntactically specified for countability, but that the derivation of countability can additionally be influenced by conceptual-semantics.

Effects of semantic variables on word production in aphasia.

Words differ in the complexity of their semantic representations and their relationships to other words and these differences can be operationalised as a variety of semantic variables. The research presented here investigates how word production in aphasia is influenced by six feature-based semantic variables (number of near semantic neighbours, semantic similarity, number of semantic features, typicality, intercorrelational density, and distinctiveness). Previous research has reported inconsistent findings for some of the semantic variables, while others have not been previously studied in aphasia. Spoken picture naming data from a large group of individuals with aphasia with mixed spoken word production impairments (n = 175) and a sub-group who produced few phonological errors (n = 60) was analysed. We examined effects of the semantic variables on overall naming accuracy and on the occurrence of different error types (semantic errors overall, coordinate errors, omissions), while controlling for other psycholinguistic variables using generalised linear mixed effects models and Bayesian correlations. Across analyses, number of semantic features was the most important predictor with a facilitatory main effect on naming accuracy in the sub-group analysis. Number of semantic features, along with typicality and semantic similarity, also predicted error types and in some analyses these effects depended on the integrity of semantic processing. Effects of the semantic variables and their theoretical explanations and implications are discussed in light of previous research and models of word production.

The relationship between response consistency in picture naming and storage impairment in people with semantic variant primary progressive aphasia.

OBJECTIVE: The progressive loss of stored knowledge about word meanings in semantic variant primary progressive aphasia (svPPA) has been attributed to an amodal "storage" deficit of the semantic system. Performance consistency has been proposed to be a key characteristic of storage deficits but has not been examined in close detail and larger participant cohorts. METHOD: We assessed whether 10 people with svPPA showed consistency in picture naming across 3 closely consecutive sessions. We examined item-by-item consistency of naming accuracy and specific error types, while controlling for the effects of word-related variables such as word frequency, familiarity, and age of acquisition. RESULTS: Participants were very consistent in their accurate and inaccurate responses over and above any effects of the word-related variables. Analyses of error types that compared consistency of semantic errors, correct responses, and other error types (e.g., phonologically related errors, unrelated errors) revealed lower consistency. CONCLUSIONS: Our findings support the assumption that semantic features constituting semantic representations of objects are progressively lost in people with svPPA and are therefore consistently unavailable during naming. Variability in the production of error types occurs when distinctive features of an object are lost, resulting in the selection of semantically or visually similar items or in the failure to select an item and a response omission. The assessment of performance consistency sheds light on the underlying impairment of people with semantic deficits (semantic storage vs. access deficit). This can support the choice of an appropriate treatment technique to maintain or reteach semantic information. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Garlic and ginger are not like apples and oranges: Effects of mass/count information on the production of noun phrases in English.

In this study a picture-word interference paradigm was used to investigate how grammatical mass/count information is processed during noun phrase production in English. Theories of lexical processing distinguish between two different types of lexical-syntactic information: variable extrinsic lexical-syntactic features, such as number (singular, plural), and fixed intrinsic lexical-syntactic properties, such as grammatical gender (e.g., masculine, feminine). Previous research using the picture-word interference paradigm has found effects of distractor lexical-syntactic congruency for grammatical gender but no congruency effects for number. We used this phenomenon to investigate whether mass/count information is processed similarly to grammatical gender. In two experiments, participants named pictures of mass or count objects using determiner noun phrases (e.g., Experiment 1 with mass and plural count nouns: "not muchmass ricemass", "not manycount pegscount"; Experiment 2 with mass and singular count nouns: "some ricemass", "a pegcount"), while ignoring distractors that were countability congruent or incongruent nouns. The results revealed a countability congruency effect for mass and plural count nouns in Experiment 1 and for singular count nouns, but not mass nouns in Experiment 2. This is similar to grammatical gender suggesting that countability processing is predominantly driven by a noun's lexical-syntactic information.

How 'some garlic' becomes 'a garlic' or 'some onion': Mass and count processing in aphasia.

This paper informs our understanding of the representation and processing of mass and count nouns through an investigation of the underlying causes of mass/count specific impairments in in two people with aphasia, DEH and GEC. The factors influencing the production of mass and count nouns and noun phrases was comprehensively assessed. The results showed that GEC's impairment affected mass noun naming, resulting in the production of semantic paraphasias and no responses. In contrast, DEH frequently substituted mass determiners with count determiners leading to ungrammatical noun phrases. In comparison to younger control group, a control group of older adults showed similar difficulties to DEH with mass noun phrases, although less severe, indicating effects of cognitive ageing on lexical and semantic processing. DEH and the elderly controls' results replicate and support previous findings regarding the lexical-syntactic representation of mass/count information. GEC's difficulties extend these findings by providing additional evidence for a semantic component in the representation of countability (e.g., a semantic feature/concept COUNTABLE for count nouns, UNCOUNTABLE for mass nouns) which contributes to mass and count noun selection. GEC's mass noun difficulties are suggested to result from weaker connection strength between noun lemmas and mass concepts compared to count concepts as a result of the overall lower frequency distribution of mass nouns.

Validation of the Emotiv EPOC EEG system for research quality auditory event-related potentials in children.

Background. Previous work has demonstrated that a commercial gaming electroencephalography (EEG) system, Emotiv EPOC, can be adjusted to provide valid auditory event-related potentials (ERPs) in adults that are comparable to ERPs recorded by a research-grade EEG system, Neuroscan. The aim of the current study was to determine if the same was true for children. Method. An adapted Emotiv EPOC system and Neuroscan system were used to make simultaneous EEG recordings in nineteen 6- to 12-year-old children under "passive" and "active" listening conditions. In the passive condition, children were instructed to watch a silent DVD and ignore 566 standard (1,000 Hz) and 100 deviant (1,200 Hz) tones. In the active condition, they listened to the same stimuli, and were asked to count the number of 'high' (i.e., deviant) tones. Results. Intraclass correlations (ICCs) indicated that the ERP morphology recorded with the two systems was very similar for the P1, N1, P2, N2, and P3 ERP peaks (r = .82 to .95) in both passive and active conditions, and less so, though still strong, for mismatch negativity ERP component (MMN; r = .67 to .74). There were few differences between peak amplitude and latency estimates for the two systems. Conclusions. An adapted EPOC EEG system can be used to index children's late auditory ERP peaks (i.e., P1, N1, P2, N2, P3) and their MMN ERP component.

Representation and processing of mass and count nouns: a review.

Comprehension and/or production of noun phrases and sentences requires the selection of lexical-syntactic attributes of nouns. These lexical-syntactic attributes include grammatical gender (masculine/feminine/neuter), number (singular/plural) and countability (mass/count). While there has been considerable discussion regarding gender and number, relatively little attention has focused on countability. Therefore, this article reviews empirical evidence for lexical-syntactic specification of nouns for countability. This includes evidence from studies of language production and comprehension with normal speakers and case studies which assess impairments of mass/count nouns in people with acquired brain damage. Current theories of language processing are reviewed and found to be lacking specification regarding countability. Subsequently, the theoretical implications of the empirical studies are discussed in the context of frameworks derived from these accounts of language production (Levelt, 1989; Levelt et al., 1999) and comprehension (Taler and Jarema, 2006). The review concludes that there is empirical support for specification of nouns for countability at a lexical-syntactic level.