Language acquisition as sparse foraging: mapping path-dependence in word

How does the acquisition of a new word affect the successive acquired ones? We model language acquisition interms of foraging in an unprecedentedly fine-grained 1-child corpus (0-3y, RoyEtAl2015). We assess whether successive wordsare learned in close semantic clusters or not (exploitation vs. exploration) and the structure of these clusters. Words are definedin terms of topic distribution in the parental input (Latent Dirichlet Allocation). Distance between successively learned wordsis measured as cosine distance between their topic distribution.Word acquisition can be accurately described as foraging in a sparse resource environment with very local path dependence(power law distribution: alpha=3.9±0.2; detrended fluctuation analysis: alpha=0.6). Words are acquired in semantically closeclusters of 2-4 successive words (Recurrence Quantification Analysis: L=2, LMAX=4, V=2, VMAX=4). The effects remainwhen controlling for shuffled baselines and temporal distance between word acquisition

Rethinking Meaning: An Ecological Perspective on Language

Abstract In a view of language as part of embodied and situated cognition, reduction of its meaning to individual mental representations ceases to be sufficient. Language relies on and at the same time enables distributed cognition thus the key aspects of meaning are in the interaction of individuals within their world. This special issue is an outcome of a workshop, which gathered representatives of several disciplines in a common effort to find appropriate theoretical concepts for the characterization of those aspects of meaning that lie in the mutual constraining between language and collective practice. The emerging picture is complex, involving multimodal participatory construction of meaning in multiple systems and on multiple timescales. The Authors, however propose also several innovative methods to navigate this complexity. In this short introduction we aim at placing the works contained in this issue on a broader map of ongoing efforts to understand language as a proper part of human ecology

Joint perceptual decision-making: a case study in explanatory pluralism.

Traditionally different approaches to the study of cognition have been viewed as competing explanatory frameworks. An alternative view, explanatory pluralism, regards different approaches to the study of cognition as complementary ways of studying the same phenomenon, at specific temporal and spatial scales, using appropriate methodological tools. Explanatory pluralism has been often described abstractly, but has rarely been applied to concrete cases. We present a case study of explanatory pluralism. We discuss three separate ways of studying the same phenomenon: a perceptual decision-making task (Bahrami et al., 2010), where pairs of subjects share information to jointly individuate an oddball stimulus among a set of distractors. Each approach analyzed the same corpus but targeted different units of analysis at different levels of description: decision-making at the behavioral level, confidence sharing at the linguistic level, and acoustic energy at the physical level. We discuss the utility of explanatory pluralism for describing this complex, multiscale phenomenon, show ways in which this case study sheds new light on the concept of pluralism, and highlight good practices to critically assess and complement approaches

Interaction, abstraction and complexity

In an experimental study, we test the hypothesis that constitutive properties of social interaction - such as diversityin cognitive styles, knowledge and experience - enhance cognitive processes of abstraction. Through three sessions, individualsand dyads categorized aliens based on combinations of features such as the shape and color of their body parts. We manipulatedrelations among the features to elicit increasingly complex categories. Furthermore, to assess the character of participants’evolving categories, after each training session they were presented to a new test set of aliens that differed in appearance, butshared relations among features with aliens from the training set. We found that dyads outcompete individuals in categorizationaccuracy across levels of complexity. We also found that this effect is due to the more abstract and rule-based character ofdyads emerging representations as evidenced by their performance on test items

Enhanced automatic action imitation and intact imitation- inhibition in schizophrenia

Imitation plays a key role in social learning and in facilitating social interactions and likely constitutes a basic building block of social cognition that supports higher-level social abilities. Recent findings suggest that patients with schizophrenia have imitation impairments that could contribute to the social impairments associated with the disorder. However, extant studies have specifically assessed voluntary imitation or automatic imitation of emotional stimuli without controlling for potential confounders. The imitation impairments seen might therefore be secondary to other cognitive, motoric or emotional deficits associated with the disorder. To overcome this issue, we used an automatic imitation paradigm with nonemotional stimuli to assess automatic imitation and the top-down modulation of imitation where participants were required to lift one of two fingers according to a number shown on the screen whilst observing the same or the other finger movement. In addition, we used a control task with a visual cue in place of a moving finger, to isolate the effect of observing finger movement from other visual cueing effects. Data from 33 patients (31 medicated) and 40 matched healthy controls were analyzed. Patients displayed enhanced imitation and intact top-down modulation of imitation. The enhanced imitation seen in patients may have been medication induced as larger effects were seen in patients receiving higher antipsychotic doses. In sum, we did not find an imitation impairment in schizophrenia. The results suggest that previous findings of impaired imitation in schizophrenia might have been due to other cognitive, motoric and/or emotional deficits

Applying the cultural ratchet to a social artefact: The cumulative cultural evolution of a language game

Material artefacts evolve by cumulative cultural evolution (CCE), the accumulation of adaptive modifications over time. We present a large-scale experiment investigating the CCE of a social artefact in transmission chains, each containing 8 adult human participants (N = 408). The social artefact is what Wittgenstein calls a 'language game', the subset of language used to perform a particular activity; in the present study the language game is to communicate a route on a map. Two social learning conditions were compared: Observational Learning and Social Coordinative Learning. Participants tried to accurately communicate a route on a map to the next person in their transmission chain. Over the experimental generations the routes were reproduced with progressively higher accuracy in both conditions, demonstrating the CCE of the language game. The rate of CCE was comparable across conditions, but route reproduction accuracy was consistently higher in the Social Coordination condition compared to the Observation condition. In both conditions performance improved due to the accumulation of adaptive patterns of verbal route descriptions, and the progressive elimination of non-adaptive patterns. Whereas change in the content of the language game was similar across conditions, change to the communication process differed between the Observation and Social Coordination conditions. In conclusion, like material artefacts, social artefacts, in our case the language game, evolve by cumulative cultural evolution