Brain Networks Responsible for Sense of Agency
Condition: Spatiotemporal Patterns
Study type: Observational

Summary: 
      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.

      ...
    

Detailed description: 
      Objective

      The purpose of this study is to investigate spatiotemporal patterns of brain networks
      involved in the sense of agency using high-resolution electroencephalography (EEG).

      Study Population

      We intend to use 20 right-hand dominant, adult healthy subjects.

      Design

      The sense of agency (SA) will be modulated using a visual task-based stimulus asking subjects
      to manipulate the position of an artificial hand projected onto a display. Subjects will use
      their own right hand to make slow opening/closing movements randomly which will be
      represented visually with the aid of a Cyberglove. During a behavioral training phase,
      subjects will practice using the apparatus. The level of control will be randomly changed to
      one of five states: 100%, 75%, 50%, 25%, 0% control. For secondary analysis, subjects will be
      asked to report the percentage of control they subjectively feel over the displayed hand.
      After subjects are comfortable with the apparatus and endorse SA over the displayed hand,
      they will undergo EEG.

      The experimental phase will have five sets of 10 minute recording sessions where the subject
      is instructed to slowly open and close their hand randomly. The level of control will be
      changed pseudo-randomly throughout the recording sessions. A control contrast consisting of
      the subject observing a moving hand will also be integrated into the blocks. An additional
      control contrast involving the subject moving their hand without visual feedback will also be
      included. These contrasts will serve in the analysis phase to help eliminate
      electrophysiological activity related to visual-motor feedback.

      A Magnetic Resonance Imaging (MRI) scan of brain will be performed to co-register this EEG
      data with the anatomical structure. We will integrate physiological (EEG) and anatomical
      (MRI) data to characterize the regionalization of the task-related brain EEG activity.

      Outcome Measures

      The primary outcome of this study is the effective connectivity of brain in response to a
      loss of SA. For this purpose, we will measure the difference of EEG power spectral analysis
      as well as coherence between 0% and 100 % control. In a secondary analysis, we will
      investigate the correlation of the EEG measurements with the percent of actual control, and
      also utilize the individual subject perceptions of percent control during the behavioral
      training phase as the regressors for activation rather than the objective control settings.
    

Keywords: Electroencephalogram (EEG); Sense of Agency; Coherence; Voluntary Movement; Self-Agency; Healthy Volunteer; HV