Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing(DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateraland bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamentalexecutive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differencesin brain functioning regarding the impact of monaural and binaural listening in CIs compared with normalhearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditoryand visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker patterndifferences in visual and auditory VWM performances in CIs compared to NH peers and possible differences betweenunilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differencesin theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivationof theta in the frontal area during the most complex condition of the auditory task and a correlation of the sameactivation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemispherewhen compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the lattertwo, a correlation was found between left hemispheric gamma oscillation and performance in the audio task.These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditoryVWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmarkfor NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targetedapproach, the diagnosis and rehabilitation of VWM in DHH children.
Two are better than one: differences in cortical EEG patterns during auditory and visual verbal working memory processing between unilateral and bilateral cochlear implanted children
Giulia Cartocci;
2024-01-01
Abstract
Despite the proven effectiveness of cochlear implant (CI) in the hearing restoration of deaf or hard-of-hearing(DHH) children, to date, extreme variability in verbal working memory (VWM) abilities is observed in both unilateraland bilateral CI user children (CIs). Although clinical experience has long observed deficits in this fundamentalexecutive function in CIs, the cause to date is still unknown. Here, we have set out to investigate differencesin brain functioning regarding the impact of monaural and binaural listening in CIs compared with normalhearing (NH) peers during a three-level difficulty n-back task undertaken in two sensory modalities (auditoryand visual). The objective of this pioneering study was to identify electroencephalographic (EEG) marker patterndifferences in visual and auditory VWM performances in CIs compared to NH peers and possible differences betweenunilateral cochlear implant (UCI) and bilateral cochlear implant (BCI) users. The main results revealed differencesin theta and gamma EEG bands. Compared with hearing controls and BCIs, UCIs showed hypoactivationof theta in the frontal area during the most complex condition of the auditory task and a correlation of the sameactivation with VWM performance. Hypoactivation in theta was also observed, again for UCIs, in the left hemispherewhen compared to BCIs and in the gamma band in UCIs compared to both BCIs and NHs. For the lattertwo, a correlation was found between left hemispheric gamma oscillation and performance in the audio task.These findings, discussed in the light of recent research, suggest that unilateral CI is deficient in supporting auditoryVWM in DHH. At the same time, bilateral CI would allow the DHH child to approach the VWM benchmarkfor NH children. The present study suggests the possible effectiveness of EEG in supporting, through a targetedapproach, the diagnosis and rehabilitation of VWM in DHH children.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
