A systematic definition of sentence topic

Bibliography: leaves 43-46Supported in part by the National Institute of Education under contract no. HEW-NIE-C-400-76-011

Towards an Indexical Model of Situated Language Comprehension for Cognitive Agents in Physical Worlds

We propose a computational model of situated language comprehension based on the Indexical Hypothesis that generates meaning representations by translating amodal linguistic symbols to modal representations of beliefs, knowledge, and experience external to the linguistic system. This Indexical Model incorporates multiple information sources, including perceptions, domain knowledge, and short-term and long-term experiences during comprehension. We show that exploiting diverse information sources can alleviate ambiguities that arise from contextual use of underspecific referring expressions and unexpressed argument alternations of verbs. The model is being used to support linguistic interactions in Rosie, an agent implemented in Soar that learns from instruction.Comment: Advances in Cognitive Systems 3 (2014

Anhedonia and depression severity dissociated by dmPFC resting-state functional connectivity in adolescents

Introduction: Given the heterogeneity within depression, in this study we aim to examine how RSFC in adolescents is related to anhedonia and depression severity on a continuum in line with the RDoC approach. Methods: We examined how RSFC in the dorsal medial prefrontal cortex (dmPFC), nucleus accumbens (NAcc) and pregenual anterior cingulate cortex (pgACC) was related to anhedonia and depression severity in eighty six adolescents (13-21 yrs.). Results: We found both anhedonia and depression severity related to decreased dmPFC RSFC with the precuneus, a part of the default mode network. However we also found that increased dmPFC connectivity with the ACC/paracingulate gyrus related to anhedonia whereas increased RSFC with the frontal pole related to depression severity. Discussion: This work extends the view that the dmPFC is a potential therapeutic target for depression in two ways. 1. We report dmPFC connectivity in adolescents and 2. We show different dmPFC RSFC specific to anhedonia and depression severity, providing neural targets for intervention in young people at risk of depression

Gaze following, gaze reading, and word learning in children at-risk for autism

We investigated gaze following abilities as a prerequisite for word learning, in a population expected to manifest a wide range of individual variability – children with a family history of autism. Three-year-olds with or without a family history of autism took part in a word-learning task that required following gaze to find the correct referent of a novel word. Using an eye-tracker to monitor children’s gaze behavior we show that the ability to follow an adult’s gaze was necessary but not sufficient for successful word learning. Those children that had poor social and communicative skills could follow gaze to the correct object, but did not then learn the word associated with that object. These findings shed light on the conditions that lead to successful or less successful word learning in typical and atypical populations

When a stone tries to climb up a slope:The interplay between lexical and perceptual animacy in referential choices

Several studies suggest that referential choices are influenced by animacy. On the one hand, animate referents are more likely to be mentioned as subjects than inanimate referents. On the other hand, animate referents are more frequently pronominalized than inanimate referents. These effects have been analyzed as effects of conceptual accessibility. In this paper, we raise the question whether these effects are driven only by lexical concepts, such that referents described by animate lexical items (e.g., “toddler”) are more accessible than referents described by inanimate lexical items (e.g., “shoe”), or can also be influenced by context-derived conceptualizations, such that referents that are perceived as animate in a particular context are more accessible than referents that are not. In two animation-retelling experiments, conducted in Dutch, we investigated the influence of lexical and perceptual animacy on the choice of referent and the choice of referring expression. If the effects of animacy are context-dependent, entities that are perceived as animate should yield more subject references and more pronouns than entities that are perceived as inanimate, irrespective of their lexical animacy. If the effects are tied to lexical concepts, entities described with animate lexical items should be mentioned as the subject and pronominalized more frequently than entities described with inanimate lexical items, irrespective of their perceptual animacy. The results show that while only lexical animacy appears to affect the choice of subject referent, perceptual animacy may overrule lexical animacy in the choice of referring expression. These findings suggest that referential choices can be influenced by conceptualizations based on the perceptual context

Slowing down fast mapping:Redefining the dynamics of word learning

In this article, we review literature on word learning and propose a theoretical account of how lexical knowledge and word use emerge and develop over time. We contend that the developing lexical system is built on processes that support children's in-the-moment word usage interacting with processes that create long-term learning. We argue for a new characterization of word learning in which simple mechanisms like association and competition, and the interaction between the two, guide children's selection of referents and word use in the moment. This in turn strengthens and refines the network of relationships in the lexicon, improving referent selection and use in future encounters with words. By integrating in-the-moment word use with long-term learning through simple domain-general mechanisms, this account highlights the dynamic nature of word learning and creates a broader framework for understanding language and cognitive development more generally

On Socio-Cultural Situatedness in Style Attribution: A Study of Style in Hungarian

Building upon the theoretical foundations of social cognitive linguistics, this paper makes the case for considering the speaker’s socio-cultural situatedness in the intersubjective context of joint attention as a key factor in the process of style attribution. Specifically, socio-cultural situatedness is regarded as a crucial component of the speaker’s perspective, playing a decisive role in the construal of style. In order to support this central assumption, the paper presents a two-phase empirical study of style in Hungarian. In the first phase, the authors conducted a questionnaire study to find out which everyday, intuitive labels of style give evidence of the speaker’s socio-cultural situatedness. The questionnaire made use of 12 excerpts of Hungarian university seminars to elicit reflections on style attributions. In the second phase, relying on the results of the first survey, a subsequent questionnaire was conducted. The aim of the second questionnaire was to operationalize folk categories of style attested in the first phase to describe style and measure stylistic markedness. Reconsidering earlier descriptive models, we found that the folk categories of style foreground different aspects of the speaker’s socio-cultural situatedness which – on a more abstract level – can be successfully described by the heuristic scientific categories of socio-cultural factors, which imply the speaker’s socio-cultural attitude to different aspects of style in the recipient’s interpretation. The speaker’s socio-cultural attitude comprises her attitude to the formation of discourse, to the discourse partner, to the value of the topic, to the temporality of constructions and to the norms of the register of the discourse

Failure to learn from feedback underlies word learning difficulties in toddlers at risk for autism

Children’s assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child’s object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word–object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism