The Neurobiology of Rhyme Judgment by Deaf and Hearing Adults: An ERP Study

Abstract

We used electrophysiology to determine the time-course and distribution of neural activation during an English word rhyme task in hearing and congenitally deaf adults. Behavioral performance by hearing participants was at ceiling and their ERP data replicated two robust effects repeatedly observed in the literature. First, a sustained negativity, termed the contingent negative variation (CNV), was elicited following the first stimulus word. This negativity was asymmetric, being more negative over the left than right sites. The second effect we replicated in hearing participants was an enhanced negativity (N450) to non-rhyming second stimulus words. This was largest over medial, parietal regions of the right hemisphere. Accuracy on the rhyme task by the deaf group as a whole was above chance level, yet significantly poorer than hearing participants. We examined only ERP data from deaf participants who performed the task above chance level (n=9). We observed indications of subtle differences in ERP responses between deaf and hearing groups. However, overall the patterns in the deaf group were very similar to that in the hearing group. Deaf participants, just as hearing participants, showed greater negativity to non-rhyming than rhyming words. Furthermore the onset latency of this effect was the same as that observed in hearing participants. Overall, the neural processes supporting explicit phonological judgments are very similar in deaf and hearing people, despite differences in the modality of spoken language experience. This supports the suggestion that phonological processing is to a large degree amodal or supramodal.

The N170 ERP component differs in laterality, distribution, and association with continuous reading measures for deaf and hearing readers

“…More recently, MacSweeney, Goswami, and Neville (2013) contrasted ERP responses in deaf and hearing adults as they performed rhyme judgments to sequentially presented written words (e.g., chair/bear pairs in which the rhyme decision could only be made using phonological knowledge). Only data from deaf participants who performed above chance ( n = 9) were analyzed (hearing participants were at ceiling).…”

Dealing with Digits : Arithmetic, Memory and Phonology in Deaf Signers

“…The lack of behavioural differences between the groups further indicates that the tasks are comparable with each other. Previous work on deaf signers and hearing individuals has shown that there are similarities between the neural substrates of phonological processing across the modalities of sign and speech (Aparicio, Gounot, Demont, & Metz-Lutz, 2007;Macsweeney et al, 2013;MacSweeney et al, 2008), suggesting an amodal representation. In the present work, a different pattern was obtained.…”

“…Evidence from both electrophysiological and brain imaging studies has shown similarities in the engagement of neural networks across the language modalities of speech and sign during phonological processing, suggesting that phonology may be represented amodally or supramodally (Macsweeney, Goswami, & Neville, 2013;MacSweeney, Waters, Brammer, Woll, & Goswami, 2008). However, there are modality-specific elements in phonological processing, evidenced by activation modulation relating to language-modality and hearing status (MacSweeney et al, 2008).…”

Representing sounds and spellings: Phonological decline and compensatory working memory in acquired hearing impairment

“…Interestingly, a recent publication examined phonological processing using behavioral and ERP measures of text-based rhyme judgments in prelingually deafened adults who were native sign language users (MacSweeney et al, 2013). MacSweeney et al (2013) found similar N400 (referred to as N450) distribution, amplitude modulation and onset latencies in the deaf and the normally hearing participants, when only individuals who had performed above chance level behaviorally (n = 9) were included. This was in spite of a significantly lower performance when measured by rhyme judgment accuracy in the deaf participants.…”

“…The present results show that the R-O+ condition may be important to include when examining rhyme judgments in individuals with HI. The study by MacSweeney et al (2013) described above did not use this condition but it would be interesting to investigate if an N2-like response would also be elicited in deaf participants.…”