Multisensory stimuli enhance 3-year-old children's executive function: A three-dimensional object version of the standard Dimensional Change Card Sort.

A three-dimensional object version of the standard Dimensional Change Card Sort (DCCS) was developed to examine the influence of multisensory stimuli on 3-year-old children's executive function. Whereas the developmental phenomenon marking 3-year-olds' difficulties with rule use in the standard DCCS can be attributed to several cognitive factors, we examined the possibility that better encoding of object features could facilitate children's rule-switching behavior. We examined whether 3-year-olds might be able to capitalize on cues available to multiple senses to create a more robust representation of object features that would enable them to overcome previous difficulties with rule switching in the standard DCCS. Participants were randomly assigned to the standard two-dimensional DCCS or the three-dimensional object version that was designed to match the rabbit and boat images used in the card version. The 3-year-olds who completed the object version outperformed those who completed the standard card version, succeeding in switching rules more accurately when provided with visual, auditory-verbal labeling, and tactile information of object features. Notably, more children achieved perfect accuracy and fewer children achieved floor-level performance in the object version than in the card version. We attribute 3-year-olds' success in the object version to greater cognitive control made possible by the enhanced encoding of the stimulus properties through multisensory input and enhanced cognitive processing of ecologically valid three-dimensional objects.

Multimodal and Spectral Degradation Effects on Speech and Emotion Recognition in Adult Listeners.

For cochlear implant (CI) users, degraded spectral input hampers the understanding of prosodic vocal emotion, especially in difficult listening conditions. Using a vocoder simulation of CI hearing, we examined the extent to which informative multimodal cues in a talker's spoken expressions improve normal hearing (NH) adults' speech and emotion perception under different levels of spectral degradation (two, three, four, and eight spectral bands). Participants repeated the words verbatim and identified emotions (among four alternative options: happy, sad, angry, and neutral) in meaningful sentences that are semantically congruent with the expression of the intended emotion. Sentences were presented in their natural speech form and in speech sampled through a noise-band vocoder in sound (auditory-only) and video (auditory-visual) recordings of a female talker. Visual information had a more pronounced benefit in enhancing speech recognition in the lower spectral band conditions. Spectral degradation, however, did not interfere with emotion recognition performance when dynamic visual cues in a talker's expression are provided as participants scored at ceiling levels across all spectral band conditions. Our use of familiar sentences that contained congruent semantic and prosodic information have high ecological validity, which likely optimized listener performance under simulated CI hearing and may better predict CI users' outcomes in everyday listening contexts.

Dance Movements Enhance Song Learning in Deaf Children with Cochlear Implants.

Music perception of cochlear implants (CI) users is constrained by the absence of salient musical pitch cues crucial for melody identification, but is made possible by timing cues that are largely preserved by current devices. While musical timing cues, including beats and rhythms, are a potential route to music learning, it is not known what extent they are perceptible to CI users in complex sound scenes, especially when pitch and timbral features can co-occur and obscure these musical features. The task at hand, then, becomes one of optimizing the available timing cues for young CI users by exploring ways that they might be perceived and encoded simultaneously across multiple modalities. Accordingly, we examined whether training tasks that engage active music listening through dance might enhance the song identification skills of deaf children with CIs. Nine CI children learned new songs in two training conditions: (a) listening only (auditory learning), and (2) listening and dancing (auditory-motor learning). We examined children's ability to identify original song excerpts, as well as mistuned, and piano versions from a closed-set task. While CI children were less accurate than their normal hearing peers, they showed greater song identification accuracies in versions that preserved the original instrumental beats following learning that engaged active listening with dance. The observed performance advantage is further qualified by a medium effect size, indicating that the gains afforded by auditory-motor learning are practically meaningful. Furthermore, kinematic analyses of body movements showed that CI children synchronized to temporal structures in music in a manner that was comparable to normal hearing age-matched peers. Our findings are the first to indicate that input from CI devices enables good auditory-motor integration of timing cues in child CI users for the purposes of listening and dancing to music. Beyond the heightened arousal from active engagement with music, our findings indicate that a more robust representation or memory of musical timing features was made possible by multimodal processing. Methods that encourage CI children to entrain, or track musical timing with body movements, may be particularly effective in consolidating musical knowledge than methods that engage listening only.

Multisensory training improves auditory spatial processing following bilateral cochlear implantation.

Cochlear implants (CIs) partially restore hearing to the deaf by directly stimulating the inner ear. In individuals fitted with CIs, lack of auditory experience due to loss of hearing before language acquisition can adversely impact outcomes. For example, adults with early-onset hearing loss generally do not integrate inputs from both ears effectively when fitted with bilateral CIs (BiCIs). Here, we used an animal model to investigate the effects of long-term deafness on auditory localization with BiCIs and approaches for promoting the use of binaural spatial cues. Ferrets were deafened either at the age of hearing onset or as adults. All animals were implanted in adulthood, either unilaterally or bilaterally, and were subsequently assessed for their ability to localize sound in the horizontal plane. The unilaterally implanted animals were unable to perform this task, regardless of the duration of deafness. Among animals with BiCIs, early-onset hearing loss was associated with poor auditory localization performance, compared with late-onset hearing loss. However, performance in the early-deafened group with BiCIs improved significantly after multisensory training with interleaved auditory and visual stimuli. We demonstrate a possible neural substrate for this by showing a training-induced improvement in the responsiveness of auditory cortical neurons and in their sensitivity to interaural level differences, the principal localization cue available to BiCI users. Importantly, our behavioral and physiological evidence demonstrates a facilitative role for vision in restoring auditory spatial processing following potential cross-modal reorganization. These findings support investigation of a similar training paradigm in human CI users.

Cross-modal perception of rhythm in music and dance by cochlear implant users.

Two studies examined adult cochlear implant (CI) users' ability to match auditory rhythms occurring in music to visual rhythms occurring in dance (Cha Cha, Slow Swing, Tango and Jive). In Experiment 1, adults CI users (n = 10) and hearing controls matched a music excerpt to choreographed dance sequences presented as silent videos. In Experiment 2, participants matched a silent video of a dance sequence to music excerpts. CI users were successful in detecting timing congruencies across music and dance at well above-chance levels suggesting that they were able to process distinctive auditory and visual rhythm patterns that characterized each style. However, they were better able to detect cross-modal timing congruencies when the reference was an auditory rhythm than when the reference was a visual rhythm. Learning strategies that encourage cross-modal learning of musical rhythms may have applications in developing novel rehabilitative strategies to enhance music perception and appreciation outcomes of child implant users.

Age-related changes in talker recognition with reduced spectral cues.

Temporal information provided by cochlear implants enables successful speech perception in quiet, but limited spectral information precludes comparable success in voice perception. Talker identification and speech decoding by young hearing children (5-7 yr), older hearing children (10-12 yr), and hearing adults were examined by means of vocoder simulations of cochlear implant processing. In Experiment 1, listeners heard vocoder simulations of sentences from a man, woman, and girl and were required to identify the talker from a closed set. Younger children identified talkers more poorly than older listeners, but all age groups showed similar benefit from increased spectral information. In Experiment 2, children and adults provided verbatim repetition of vocoded sentences from the same talkers. The youngest children had more difficulty than older listeners, but all age groups showed comparable benefit from increasing spectral resolution. At comparable levels of spectral degradation, performance on the open-set task of speech decoding was considerably more accurate than on the closed-set task of talker identification. Hearing children's ability to identify talkers and decode speech from spectrally degraded material sheds light on the difficulty of these domains for child implant users.

Children With Cochlear implants recognize their mother's voice.

OBJECTIVES: The available research indicates that cochlear implant (CI) users have difficulty in differentiating talkers, especially those of the same gender. The goal of this study was to determine whether child CI users could differentiate talkers under favorable stimulus and task conditions. We predicted that the use of a highly familiar voice, full sentences, and a game-like task with feedback would lead to higher performance levels than those achieved in previous studies of talker identification in CI users. DESIGN: In experiment 1, 21 CI users aged 4.8 to 14.3 yrs and 16 normal-hearing (NH) 5-yr-old children were required to differentiate their mother's scripted utterances from those of an unfamiliar man, woman, and girl in a four-alternative forced-choice task with feedback. In one condition, the utterances incorporated natural prosodic variations. In another condition, nonmaternal talkers imitated the prosody of each maternal utterance. In experiment 2, 19 of the child CI users and 11 of the NH children from experiment 1 returned on a subsequent occasion to participate in a task that required them to differentiate their mother's utterances from those of unfamiliar women in a two-alternative forced-choice task with feedback. Again, one condition had natural prosodic variations and another had maternal imitations. RESULTS: Child CI users in experiment 1 succeeded in differentiating their mother's utterances from those of a man, woman, and girl. Their performance was poorer than the performance of younger NH children, which was at ceiling. Child CI users' performance was better in the context of natural prosodic variations than in the context of imitations of maternal prosody. Child CI users in experiment 2 differentiated their mother's utterances from that of other women, and they also performed better on naturally varying samples than on imitations. CONCLUSIONS: We attribute child CI users' success on talker differentiation, even on same-gender differentiation, to their use of two types of temporal cues: variations in consonant and vowel articulation and variations in speaking rate. Moreover, we contend that child CI users' differentiation of speakers was facilitated by long-term familiarity with their mother's voice.

Bilateral cochlear implantation in the ferret: a novel animal model for behavioral studies.

Bilateral cochlear implantation has recently been introduced with the aim of improving both speech perception in background noise and sound localization. Although evidence suggests that binaural perception is possible with two cochlear implants, results in humans are variable. To explore potential contributing factors to these variable outcomes, we have developed a behavioral animal model of bilateral cochlear implantation in a novel species, the ferret. Although ferrets are ideally suited to psychophysical and physiological assessments of binaural hearing, cochlear implantation has not been previously described in this species. This paper describes the techniques of deafening with aminoglycoside administration, surgical implantation of an intracochlear array and chronic intracochlear electrical stimulation with monitoring for electrode integrity and efficacy of stimulation. Experiments have been presented elsewhere to show that the model can be used to study behavioral and electrophysiological measures of binaural hearing in chronically implanted animals. This paper demonstrates that cochlear implantation and chronic intracochlear electrical stimulation are both safe and effective in ferrets, opening up the possibility of using this model to study potential protective effects of bilateral cochlear implantation on the developing central auditory pathway. Since ferrets can be used to assess psychophysical and physiological aspects of hearing along with the structure of the auditory pathway in the same animals, we anticipate that this model will help develop novel neuroprosthetic therapies for use in humans.

Music in the lives of deaf children with cochlear implants.

Present-day cochlear implants provide good temporal cues and coarse spectral cues. In general, these cues are adequate for perceiving speech in quiet backgrounds and for young children's acquisition of spoken language. They are inadequate, however, for conveying the rich pitch-patterning of music. As a result, many adults who become implant users after losing their hearing find music disappointing or unacceptable. By contrast, child implant users who were born deaf or became deaf as infants or toddlers typically find music interesting and enjoyable. They recognize popular songs that they hear regularly when the test materials match critical features of the original versions. For example, they can identify familiar songs from the original recordings with words and from versions that omit the words but preserve all other cues. They also recognize theme songs from their favorite television programs when presented in original or somewhat altered form. The motivation of children with implants for listening to music or melodious speech is evident well before they understand language. Within months after receiving their implant, they prefer singing to silence. They also prefer speech in the maternal style to typical adult speech and the sounds of their native language-to-be to those of a foreign language. An important task of future research is to ascertain the relative contributions of perceptual and motivational factors to the apparent differences between child and adult implant users.

Effect of age on F0 difference limen and concurrent vowel identification.

PURPOSE: To investigate the effect of age on voice fundamental frequency (F0) difference limen (DL) and identification of concurrently presented vowels. METHOD: Fifteen younger and 15 older adults with normal audiometric thresholds in the speech range participated in 2 experiments. In Experiment 1, F0 DLs were measured for a synthesized vowel. In Experiment 2, accuracy in identifying concurrently presented vowel pairs was measured. Vowel pairs were formed from 5 synthesized vowels with F0 separations ranging from 0 to 4 semitones. RESULTS: Younger adults had smaller (better) F0 DLs than older adults. For the older group, age was significantly correlated with F0 DLs. Younger adults identified concurrent vowels more accurately than older adults. When the vowels in the pairs had different formants, both age groups benefited similarly from F0 separation. Interestingly, when both constituent vowels had identical formants, F0 separation was deleterious, especially for older adults. Pure-tone average threshold did not correlate significantly with either F0 DL or accuracy in concurrent vowel identification. CONCLUSION: Age-related declines were confirmed for F0 DLs, identification of concurrently spoken vowels, and benefit from F0 separation between vowels with identical formants. This pattern of findings is consistent with age-related deficits in periodicity coding.

Song recognition by children and adolescents with cochlear implants.

PURPOSE: To assess song recognition and pitch perception in prelingually deaf individuals with cochlear implants (CIs). METHOD: Fifteen hearing children (5-8 years) and 15 adults heard different versions of familiar popular songs-original (vocal + instrumental), original instrumental, and synthesized melody versions-and identified the song in a closed-set task (Experiment 1). Ten CI users (8-18 years) and age-matched hearing listeners performed the same task (Experiment 2). Ten CI users (8-19 years) and 10 hearing 8-years-olds were required to detect pitch changes in repeating-tone contexts (Experiment 3). Finally, 8 CI users (6-19 years) and 13 hearing 5-year-olds were required to detect subtle pitch changes in a more challenging melodic context (Experiment 4). RESULTS: CI users performed more poorly than hearing listeners in all conditions. They succeeded in identifying the original and instrumental versions of familiar recorded songs, and they evaluated them favorably, but they could not identify the melody versions. Although CI users could detect a 0.5-semitone change in the simple context, they failed to detect a 1-semitone change in the more difficult melodic context. CONCLUSION: Current implant processors provide insufficient spectral detail for some aspects of music perception, but they do not preclude young implant users' enjoyment of music.