Impaired face recognition is associated with abnormal gray matter volume in the posterior cingulate cortex in congenital amusia.

Congenital amusia is as a neurodevelopment disorder primarily defined by impairment in pitch discrimination and pitch memory. Interestingly, it has been reported that individuals with congenital amusia also exhibit deficits in face recognition (prosopagnosia). One explanation of such comorbidity is that the neural substrates of pitch recognition and face recognition may be similar. To test this hypothesis, face recognition ability was assessed using the Cambridge Face Memory Test (CFMT) and gray matter volume was determined through voxel-based morphometry (VBM) among participants with and without congenital amusia. As expected, participants with amusia performed worse on the CFMT test and showed reduced gray matter volume (GMV) in the middle temporal gyrus (MTG), the superior temporal gyrus (STG), and the posterior cingulate cortex (PCC) in the right hemisphere, when compared with matched controls. Furthermore, correlation analyses demonstrated that the CFMT score was positively related to MTG, STG, and PCC GMV in all participants, while separate analyses of each group found a positive correlation of CFMT score and PCC GMV in amusics. These findings suggest that face recognition is associated with a widely distributed microstructural network in the human brain and the PCC plays an important role in both pitch recognition and face recognition in amusics. In addition, neurodevelopmental disorders such as congenital amusia and prosopagnosia may share a common neural substrate.