| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 3043531 | Clinical Neurophysiology | 2013 | 8 Pages |
ObjectiveTo investigate 1: plasticity due to partial unilateral deafness of slow onset and 2: the time course of plasticity following abrupt, profound unilateral deafness in adult humans using cortical auditory evoked potentials.MethodsBaseline data were measured from six participants with partial unilateral deafness due to an acoustic neuroma and compared with data from six controls. Further measurements were made in the unilaterally deaf group at 1-, 3- and 6-months post surgery for acoustic neuroma removal and consequent profound unilateral deafness. Data were recorded from 30 channels in response to pure tones presented to the intact ear.ResultsBaseline data revealed statistically higher amplitudes in unilaterally deaf participants but with normal hemispheric asymmetry. Longitudinal data revealed further increases in P1 amplitudes by 1-month post-surgery, and in N1 and P2 amplitudes by 6-months post-surgery, with statistically different scalp field topographies indicating reduced hemispheric asymmetries.ConclusionDifferent patterns of plasticity occur following partial and profound unilateral deafness. Plasticity occurs both relatively rapidly and more gradually over at least 6-months post-surgery.SignificanceThe different patterns of change over time are consistent with multiple physiological mechanisms of plasticity. Unravelling these mechanisms and their time course in humans may be relevant in understanding and, ultimately, influencing plasticity for therapeutic gain.
► Experience-related plasticity is apparent in adult humans with both partial and profound unilateral deafness, reflected by altered cortical evoked potentials. ► Changes occur within 1-month post-onset of profound unilateral deafness, and continue for at least 6-months. ► Differences in the pattern of change between partial and profound deafness, and the time course of changes after onset of profound deafness, suggest the presence of multiple physiological triggers and mechanisms of plasticity in humans.
