1. A device comprising: a first elongated band coupled to a first housing to be located near a first ear of a subject and a second housing to be located near a second ear of the subject, the first elongated band comprising a first set of electrodes having at least eight electrodes; a second elongated band coupled to the first housing and to the second housing, the second elongated band comprising a second set of electrodes having at least eight electrodes; a third elongated band coupled to the first housing and to the second housing, the third elongated band comprising a third set of electrodes having at least eight electrodes; and a fourth elongated band coupled to the first housing and to the second housing, the fourth elongated band comprising a fourth set of electrodes having at least eight electrodes.