The Disability Rating Scale (DRS) was developed by Michael Rappaport and colleagues in 1977 to correlate levels of disability with evoked brain potentials and chart the progress of patients who fall in the midrange spectrum of recovery, generally described as being in MCS. The DRS is broken into four categories as evidenced by specific constituent behaviors: arousability, awareness and responsivity  (eye opening, verbalization, motor response); cognitive ability for self-care activities (feeding, toileting, grooming); dependence  on others (level of functioning) and psychosocial adaptability (employability).  Each item gets its own score, with a zero indicating normal functioning, with a possible total of 29, which indicates the lowest level of functioning.