Abstract: A wearable device for recording biometric information from a person's brain can be embodied in a pair of smart headphones with electrodes or in a biauricular headset with electrodes. This wearable device can position a plurality of electrodes on a person's head at a subset of the following MCN electrode placement sites: CP1, CP2, CP3, CP4, CP5, CP6, CPz, FC1, FC2, FC3, FC4, FC5, FC6, FCz, O1, O2, Oz, P7, P8, PO7, PO8, TP7 and TP8.