Representing meaning: a feature-based model of object and action words

The representation of word meaning has received substantial attention in the psycholinguistic literature over the past decades, yet the vast majority of studies have been limited to words referring to concrete objects. The aim of the present work is to provide a theoretically and neurally plausible model of lexical-semantic representations, not only for words referring to concrete objects but also for words referring to actions and events using a common set of assumptions across domains. In order to do so, features of meaning are generated by naïve speakers, and used as a window into important aspects of representation. A first series of analyses test how the meanings of words of different types are reflected in features associated with different modalities of sensory-motor experience, and how featural properties may be related to patterns of impairment in language-disordered populations. The features of meaning are then used to generate a model of lexical-semantic similarity, in which these different types of words are represented within a single system, under the assumption that lexical-semantic representations serve to provide an interface between conceptual knowledge derived in part from sensory-motor experience, and other linguistic information such as syntax, phonology and orthography. Predictions generated from this model are tested in a series of behavioural experiments designed to test two main questions: whether similarity measures based on speaker- generated features can predict fine-grained semantic similarity effects, and whether the predictive quality of the model is comparable for words referring to objects and words referring to actions. The results of five behavioural experiments consistently reveal graded semantic effects as predicted by the feature-based model, of similar magnitude for objects and actions. The model's fine-grained predictive performance is also found to be superior to other word-based models of representation (Latent Semantic Analysis, and similarity measures derived from Wordnet)

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

Introduction: The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures. Methods: In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025. Findings: Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2–6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p5mg/L, OR 3·55 [1·23–11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation. Interpretation: After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification. Funding: UK Research and Innovation and National Institute for Health Research

Representing meaning: a feature-based model of object and action words .

The representation of word meaning has received substantial attention in the psycholinguistic literature over the past decades, yet the vast majority of studies have been limited to words referring to concrete objects. The aim of the present work is to provide a theoretically and neurally plausible model of lexical-semantic representations, not only for words referring to concrete objects but also for words referring to actions and events using a common set of assumptions across domains. In order to do so, features of meaning are generated by naïve speakers, and used as a window into important aspects of representation. A first series of analyses test how the meanings of words of different types are reflected in features associated with different modalities of sensory-motor experience, and how featural properties may be related to patterns of impairment in language-disordered populations. The features of meaning are then used to generate a model of lexical-semantic similarity, in which these different types of words are represented within a single system, under the assumption that lexical-semantic representations serve to provide an interface between conceptual knowledge derived in part from sensory-motor experience, and other linguistic information such as syntax, phonology and orthography. Predictions generated from this model are tested in a series of behavioural experiments designed to test two main questions: whether similarity measures based on speaker- generated features can predict fine-grained semantic similarity effects, and whether the predictive quality of the model is comparable for words referring to objects and words referring to actions. The results of five behavioural experiments consistently reveal graded semantic effects as predicted by the feature-based model, of similar magnitude for objects and actions. The model's fine-grained predictive performance is also found to be superior to other word-based models of representation (Latent Semantic Analysis, and similarity measures derived from Wordnet).

Representing meaning

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Word learning in two languages: Neural overlap and representational differences

Contains fulltext : 227415.pdf (publisher's version ) (Closed access)We investigated the neural basis of newly learned words in Spanish as a mother tongue (L1) and English as a second language (L2). Participants acquired new names for real but unfamiliar concepts in both languages over the course of two days. On day 3, they completed a semantic categorization task during fMRI scanning. The results revealed largely overlapping brain regions for newly learned words in Spanish and English. However, Spanish showed a heightened BOLD response within prefrontal cortex (PFC), due to increased competition of existing lexical representations. In contrast, English displayed higher activity than Spanish within primary auditory cortex, which suggests increased phonological processing due to more irregular phonological-orthographic mappings. Overall, these results suggest that novel words are learned similarly in Spanish L1 and English L2, and that they are represented in largely overlapping brain regions. However, they differ in terms of cognitive control and phonological processes.10 p

Role of grammatical gender and semantics in German word production

Contains fulltext : 64468.pdf (publisher's version ) (Closed access)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. Marx, 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.15 p