Verb bias and verb-specific competition effects on sentence production.

Malathi Thothathiri,Sonali Poudel,Daniel G Evans,Frederic Dick

doi:10.1371/journal.pone.0180580

Abstract

How do speakers choose between structural options for expressing a given meaning? Overall preference for some structures over others as well as prior statistical association between specific verbs and sentence structures (“verb bias”) are known to broadly influence language use. However, the effects of prior statistical experience on the planning and execution of utterances and the mechanisms that facilitate structural choice for verbs with different biases have not been fully explored. In this study, we manipulated verb bias for English double-object (DO) and prepositional-object (PO) dative structures: some verbs appeared solely in the DO structure (DO-only), others solely in PO (PO-only) and yet others equally in both (Equi). Structural choices during subsequent free-choice sentence production revealed the expected dispreference for DO overall but critically also a reliable linear trend in DO production that was consistent with verb bias (DO-only > Equi > PO-only). Going beyond the general verb bias effect, three results suggested that Equi verbs, which were associated equally with the two structures, engendered verb-specific competition and required additional resources for choosing the dispreferred DO structure. First, DO production with Equi verbs but not the other verbs correlated with participants’ inhibition ability. Second, utterance duration prior to the choice of a DO structure showed a quadratic trend (DO-only < Equi > PO-only) with the longest durations for Equi verbs. Third, eye movements consistent with reimagining the event also showed a quadratic trend (DO-only < Equi > PO-only) prior to choosing DO, suggesting that participants used such recall particularly for Equi verbs. Together, these analyses of structural choices, utterance durations, eye movements and individual differences in executive functions shed light on the effects of verb bias and verb-specific competition on sentence production and the role of different executive functions in choosing between sentence structures.

Highlights

The observed pattern is consistent with an expected dispreference for DO overall combined with modulation according to verb bias
Inhibition scores correlated with proportion of DO produced with equally in both (Equi) verbs
Using unscaled difference scores yielded a similar pattern, with the sole exception being that switching scores did not correlate with proportion of DO produced with Equi verbs (r = 0.19 CI = [-0.02 0.39])

Summary

Introduction

Switching appears to involve flexibility in using different task rules in different contexts, which is distinct from the ability to inhibit distracting information [20,21] Consistent with such a dissociation and directly related to sentence production, a previous study found that structural choice in different verb bias conditions in an artificial language correlated differently with inhibition and switching performance [9]. Our results shed light on how verb bias and verb-specific competition influence sentence production and highlight the potential role of different executive functions in making structural choices

Method Participants

Results

Discussion

Summary