Abstract: An apparatus for diagnosing or treating a neurological disorder, usually associated with a lack of attentiveness, in a subject by detecting the subject's eye movement. The apparatus includes a helmet for blocking visual stimuli from the subject's visual field; at least three visual cues disposed inside the helmet within the visual field of the subject when the helmet is placed on the subject's head, the visual cues capable of being switched from on to off states; at least two electrodes for attaching to the subject's face, the electrodes producing electrical signals corresponding to the subject's eye movements; signal processing means for controlling on and off states of the visual cues, receiving and processing electrical signals produced by the electrodes, and producing output signals corresponding to the subject's eye movements; and means for displaying output signals produced by the signal processing means.