The Effect of Presentation Mode and Production Type on Word Memory for Hearing Impaired Signers.

BACKGROUND: Production effect (PE) is a memory phenomenon referring to better memory for produced (vocalized) than for non-produced (silently read) items. Reading aloud was found to improve verbal memory for normal-hearing individuals, as well as for cochlear implant users, studying visually and aurally presented material. PURPOSE: The present study tested the effect of presentation mode (written or signed) and production type (vocalization or signing) on word memory in a group of hearing impaired young adults, sign-language users. RESEARCH DESIGN: A PE paradigm was used, in which participants learned lexical items by two presentation modes, written or signed. We evaluated the efficacy of two types of productions: vocalization and signing, using a free recall test. STUDY SAMPLE: Twenty hearing-impaired young adults, Israeli sign language (ISL) users, participated in the study, ten individuals who mainly use manual communication (MC) (ISL as a first language), and ten who mainly use total communication (TC). DATA COLLECTION AND ANALYSIS: For each condition, we calculated the proportion of study words recalled. A mixed-design analysis of variance was conducted, with learning condition (written-vocalize, written-signed, and manual-signed) and production type (production and no-production) as within-subject variables, and group (MC and TC) as a between-subject variable. RESULTS: Production benefit was documented across all learning conditions, with better memory for produced over non-produced words. Recall rates were higher when learning written words relative to signed words. Production by signing yielded better memory relative to vocalizing. CONCLUSIONS: The results are explained in light of the encoding distinctiveness account, namely, the larger the number of unique encoding processes involved at study, the better the memory benefit.

Evidence for a right cochlear implant advantage in simultaneous bilateral cochlear implantation.

OBJECTIVES/HYPOTHESIS: To compare speech perception performance with right versus left cochlear implants (CIs) in children with bilateral CIs implanted simultaneously. STUDY DESIGN: Prospective case series of patients undergoing simultaneous bilateral cochlear implantation. METHODS: Speech perception performance was tested in 10, right-handed children who received bilateral CIs simultaneously between 11 and 36 months (mean, 21 months), had at least 18 months of bilateral CI use, and were 5.3 years of age during testing. All children exhibited bilateral symmetrical severe-to-profound hearing loss prior to implantation and did not benefit from hearing aids. Speech perception performance was evaluated with the right CI and the left CI by means of an open-set monosyllabic word test in quiet presented at 45 dB HL in a sound field. RESULTS: All children exhibited higher performance with the right CI compared to the left CI. Group mean performance with the right CI was 66.5% compared to 52% with the left CI (P = .002), yielding a 14.5% difference. With increasing duration of bilateral CI use and age at evaluation, the right-left difference increased (r = 0.72, P = .019 and r = 0.74, P = .014, respectively). CONCLUSIONS: Current preliminary data indicate that children with bilateral CIs implanted simultaneously exhibit a significant right ear advantage for speech. Similarly to reports on normal-hearing children, right ear preference for speech increased with increasing age and auditory-linguistic experience. Thus, simultaneous bilateral cochlear implantation may lead to normal development of auditory pathways and may be an important contributor to the superior auditory, language, and communication skills reported in children with bilateral versus unilateral CIs.