Brain Networks Responsible for Sense of Agency

This study of healthy normal volunteers will examine the brain networks involved in people's sense that they control their own movements (sense of agency). Although almost everyone has a sense of agency, some patients (for example, patients with schizophrenia, alien limb phenomena, and others) have movements they think are not under their control. This study will use electroencephalography (EEG) to determine how the normal brain produces the sense of agency. This information will provide a first step in understanding patients with an impaired sense of agency. Healthy, right-handed men and women 18 years of age and older may be eligible for this study. Candidates are screened with a medical history and neurological examination. Participants are fitted with a cyberglove device (a lightweight glove with flexible sensors that measure the position and movement of the fingers and wrist) on their right hand. The glove is used to transform the subject's hand and finger motions into real-time digital joint-angle information. Subjects slowly open and close their hand while watching an artificial hand projected on a monitor. They continue practicing the exercise until they are comfortable with the cyberglove and have the sense that the artificial hand is a mirror representation of their own hand, accurately reflecting their hand's movements. After practicing with the cyberglove, subjects have a functional EEG. For this test, electrodes are placed on the scalp, and brain waves are recorded while the subject opens and closes his or her hand or just watches the computer monitor. The EEG recording takes about 60 minutes. ...