A head set (2) comprises a brain electrical activity (EEG) sensing device (3) comprising EEG sensors (22) configured to be mounted on a head of a wearer so as to position the EEG sensors (22) at selected positions of interest over the wearers scalp, the EEG sensing device comprising a sensor support (4) and a flexible circuit (6) assembled to the sensor support. The sensor support and flexible circuit comprise a central stem (4a, 6a) configured to extend along a center plane of the top of the head in a direction from a nose to a centre of the back of a wearers head, a front lateral branch (4b, 6b) configured to extend across a front portion of a wearer's head extending laterally from the central stem, a center lateral branch (4c, 6c) configured to extend across a top portion of a wearer's head essentially between the wearer's ears, and a rear lateral branch (4d, 6d) configured to extend across a back portion of a wearer's head.
