MAPT and supranuclear palsy, progressive, 1: With regard to PSP and CBS, also belonging to the FTLD spectrum of neurodegeneration (i.e., abnormal function/levels of the microtubule associated protein tau), patients affected by PSP may exhibit impaired facial (i.e., sadness and sadness) and voice emotion recognition [188, 189] as well as CBS patients, who may exhibit difficulties in recognizing disgust, sadness, surprise, and happiness, but not anger and fear [163].