Disinhibited feedback as a cause of synesthesia: Evidence from a functional connectivity study on auditory-visual synesthetes

► Different functional connectivity has been detected according to synesthesia. ► Inferior parietal cortex is stronger connected to auditory and visual cortex. ► No stronger connectivity could be detected between auditory and visual cortex. ► The results provide evidence for the model of disinhibited feedback in synesthesia. ► No evidence is found for the model of cross-activation.