Learning and generalizing non-adjacent dependencies in 18-month-olds: A mechanism for language acquisition?

Ileana Grama,Frank Wijnen

doi:10.1371/journal.pone.0204481

Ileana Grama, Frank Wijnen

Open Access

https://doi.org/10.1371/journal.pone.0204481

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Abstract

The ability to track non-adjacent dependencies (the relationship between ai and bi in an aiXbi string) has been hypothesized to support detection of morpho-syntactic dependencies in natural languages (‘The princess is reluctantly kissing the frog’). But tracking such dependencies in natural languages entails being able to generalize dependencies to novel contexts (‘The general is angrily berating his troops’), and also tracking co-occurrence patterns between functional morphemes like is and ing (a class of elements that often lack perceptual salience). We use the Headturn Preference Procedure to investigate (i) whether infants are capable of generalizing dependencies to novel contexts, and (ii) whether they can track dependencies between perceptually non-salient elements in an artificial grammar aXb. Results suggest that 18-month-olds extract abstract knowledge of a_b dependencies between non-salient a and b elements and use this knowledge to subsequently re-familiarize themselves with specific ai_bi combinations. However, they show no evidence of generalizing ai_bi dependencies to novel aiYbi strings.

Highlights

The remarkable ability of children to acquire their native language within a few years has often been attributed, at least partially, to their ability to detect distributional properties of the input
The current study is concerned with the learning ability that allows both adults and infants to identify non-adjacent dependencies (NADs): co-occurrence patterns between elements that are non-adjacent in a sequence
This study was approved by the Ethische Toetsings Commissie Linguïstiek (ETCL) of Utrecht University

Summary

Introduction

The remarkable ability of children to acquire their native language within a few years has often been attributed, at least partially, to their ability to detect distributional properties of the input. Kerkhoff & Wijnen [14] extended Newport & Aslin’s [13] discussion of the relevance of NAD-learning to language acquisition They showed that adult learners were capable of generalization of aiXbi dependencies to novel contexts (aiYbi), where the intervening element Y was withheld from familiarization. Experiment 2 investigates whether 18-month-olds are capable of detecting dependencies between prosodically reduced elements in the same way that adults are, and whether Gestalt principles of perception guide learning in infant learners, not just adults This experiment investigates the ability to generalize patterns between non-adjacent words to novel contexts. Strings were approximately 2s in duration and were played separated by 750ms pauses

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