Semantic Processing in Deaf and Hard-of-Hearing Children: Large N400 Mismatch Effects in Brain Responses, Despite Poor Semantic Ability.

Petter Kallioinen,Elisabet Engström,Jonas Olofsson,Magnus Lindgren,Cecilia Nakeva Von Mentzer,Inger Uhlén,Björn Lyxell,Birgitta S Sahlén,Marianne Ors

doi:10.3389/fpsyg.2016.01146

Abstract

Difficulties in auditory and phonological processing affect semantic processing in speech comprehension for deaf and hard-of-hearing (DHH) children. However, little is known about brain responses related to semantic processing in this group. We investigated event-related potentials (ERPs) in DHH children with cochlear implants (CIs) and/or hearing aids (HAs), and in normally hearing controls (NH). We used a semantic priming task with spoken word primes followed by picture targets. In both DHH children and controls, cortical response differences between matching and mismatching targets revealed a typical N400 effect associated with semantic processing. Children with CI had the largest mismatch response despite poor semantic abilities overall; Children with CI also had the largest ERP differentiation between mismatch types, with small effects in within-category mismatch trials (target from same category as prime) and large effects in between-category mismatch trials (where target is from a different category than prime), compared to matching trials. Children with NH and HA had similar responses to both mismatch types. While the large and differentiated ERP responses in the CI group were unexpected and should be interpreted with caution, the results could reflect less precision in semantic processing among children with CI, or a stronger reliance on predictive processing.

Highlights

In a spoken language environment, impaired hearing can limit the development of words, concepts and language comprehension and communication in children
Four more children participated in the study but were excluded from the present analysis
Semantic processing in deaf and hard-of-hearing (DHH) children has been largely unexplored at the neural level

Summary

Introduction

In a spoken language environment, impaired hearing can limit the development of words, concepts and language comprehension and communication in children. An underdeveloped semantic structure (i.e., the taxonomic, associative or similaritybased relations between words) could be expected, but research indicates a large heterogeneity among DHH children (Peterson et al, 2010; Löfkvist et al, 2012; Kenett et al, 2013; Li et al, 2013; Nakeva von Mentzer, 2014). Semantic and other cognitive cues may play a more important role in linguistic processing of DHH children, as a means to compensate for poor phonological skills (Lyxell et al, 2009; Nakeva von Mentzer et al, 2014a). Predicting semantic content might be of importance for DHH persons, due to their difficulties in extracting semantic content from speech input

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Conclusion