fNIRS Changes in the Middle Temporal and Occipital Cortices After a Cochlear Implant

Objectives The relationship between the middle temporal (MTG) and occipital cortices in post‐lingually deaf (PLD) individuals is unclear. This study aimed to investigate changes in the MTG and occipital cortices excitability and their effects on the occipital cortex in individuals with PLD after receiving a cochlear implant (CI). Methods Twenty‐six individuals with severe‐to‐profound binaural sensorineural PLD were assessed clinically. Nine individuals had received a unilateral cochlear implant over 6 months, while 17 had not. Brodmann area 19 (BA19, extra‐striate occipital cortex) and MTG (auditory‐related area of cortex) were selected as regions of interest. The excitability of the ROI was observed and compared in the surgery and no‐surgery groups by functional near‐infrared spectroscopy (fNIRS) in the resting state, and correlations between connectivity of the MTG and occipital cortex, and as well as the duration of time that had elapsed following CI surgery, were investigated. Results fNIRS revealed enhanced global cortical connectivity in the BA19 and MTG on the operative side (p