A device for measuring intracortical brain activity of a subject is provided. The device includes a support member configured for intracranial insertion in the subject. The device comprises a plurality of electrodes are positioned in an electrode region of the support member, which is configured to traverse the cerebral cortex of the subject when the support member is inserted intracranially in the subject. In certain embodiments, the device further comprises drainage region positioned on the support member such that two or more electrodes in the electrode region contact the cerebral cortex of the subject when the drainage region of the support member is in fluid contact with cerebrospinal fluid in the brain ventricle of the subject. In certain embodiments, the device further comprises a detector or probe for monitoring an additional brain parameter.
