Uyrtyut

PET, have prevented the imaging of neural changes associated with initial perceptual and linguistic processing of the novel-sounding CI input. The current study used fMRI and a simulation of the spectral resolution and spectral shifting of a cochlear implant. Its aim was to identify cortical changes in naive, hearing listeners as they learnt to understand this novel input over the course of a training session,

Cochlear implants (CIs) can restore hearing after sensorineural hearing loss, or provide auditory input to children born deaf. These prostheses deliver tonotopically distributed electrical stimulation to the auditory nerve via an electrode array that is inserted into the cochlea. CIs provide a limited degree of spectral resolution, sufficient for good speech intelligibility in quiet

Differences in the engagement of left inferior prefrontal cortex, and its covariation with posterior parietal areas, may thus underlie some of the variation in speech perception skills that have been observed in clinical populations of CI users.

AG and IFG was modulated by the learnability of the stimuli. These results suggest that variation in listeners' ability to adjust to vocoded and spectrally shifted speech is partly reflected in differences in the recruitment of higher-level language processes in prefrontal cortex, and that this variability may further depend on functional links between the left inferior frontal gyrus and angular gyrus.

Neurally, left-lateralized regions in superior temporal sulcus and inferior frontal gyrus (IFG) were sensitive to the learnability of the simulations, but only the activity in prefrontal cortex correlated with interindividual variation in intelligibility scores and phonological working memory. A region in left angular gyrus (AG) showed an activation pattern that reflected learning over the course of the experiment, and covariation of activity

This study investigated the neural plasticity associated with perceptual learning of a cochlear implant (CI) simulation. Normal-hearing listeners were trained with vocoded and spectrally shifted speech simulating a CI while cortical responses were measured with functional magnetic resonance imaging (fMRI). A condition in which the vocoded speech was spectrally inverted provided a control for learnability and adaptation. Behavioral measures showed considerable individual variability both in the ability to learn to understand the degraded speech, and in phonological working memory capacity.