Abstract
Using visual evoked potentials (VEP), the cortical network engaged by apparent motion in the central and peripheral visual field in twenty subjects with normal hearing was compared with that in five patients who received a cochlear implant (CI) after a period of profound deafness. All the patients wore the CI for two years, but they did not react in the same manner to the reintroduction of the auditory input. The three first patients (SL, SB and JFR) quickly learned to use the device whereas the fourth patient (JD) resigned after having attempted unsuccessfully for a full year, and the fifth (JME) and the sixth (JSG) patients had mitigated success using the CI. The visual evoked potentials of the three most successful CI users showed supranormal amplitudes in their VEP but only after the CI implantation; the waveforms of the other CI users did not strikingly differ from those of the control participants. These results are interpreted and discussed in terms of intermodal plasticity.
This research was supported by grants from the FRSQ, CRSNG and IRSC.