Most patients with minimal consciousness status in Critical Care Units (CCU) are considered as an 'unconscious patient' with a neurological examination. A study showed that only 5% of intensive care nurses communicate with the unconscious patients and the content of the communication with them is to explain only the procedures to apply. Lack of communication with these patients can be transformed into the sense of 'non-responsive patient' among healthcare providers. Evaluating these patients as unconscious patients may lead to neglect of psychosocial needs in patient-care, a continuation of unchanged treatment protocols for a long time and desperate evaluation of prognosis. Moreover, it may lead to burnout syndrome over time for physicians and nurses in the CCU. In particular, the futile care perception of caregiving about unconscious patient prolongs the recovery process and length of stay in CCU. On the other hand, it may lead to the occupation of beds and increases the costs. Coma and sedation scoring systems such as Glasgow Coma Scale (GCS), Ramsey Sedation Scale (RSS) and Full Outline of Unresponsiveness (FOUR) have traditionally been used to assess the consciousness in CCU. These scoring systems may be insufficient to assess the psychophysiological status of the patients. Some researches on the unconscious patients have shown that these patients are aware of their surroundings. However, the data for these studies were obtained from interviews with patients who were previously experiencing unconsciousness, or with caregivers in CCU. The balance between sympathetic and parasympathetic systems is controlled by the autonomic nervous system. The response of the sympathetic system to external stimuli is different in many organs of the body. For example, a painful stimulus causes myosis in the eyes, hypertension, and tachycardia. Emotional stimuli also activate the sympathetic system. Fear and excitement lead to mydriasis, elevation of blood pressure and tachycardia, and activation of eccrine gland increase to release of sweating. Electrophysiological tests are objective methods in which the physiological signals and psychological states of emotion are acquired by noninvasively connected superficial electrodes. Through this method, the R-R interval (velocity analysis) can be evaluated by the Poincare Plot analysis in the electrocardiogram (ECG) to measure the electrical activity of the heart. Electrooculography (EOG) is a test that evaluates the eyes movements. In EOG, the source of the signals is the stationary electrical potential between the cornea and the retina. The EOG is composed of the changes of the electricity based on the movements of the eyeball around the eye center. Galvanic skin response (GSR) is a test used to measure skin conductivity and reflects electrodermal activity. In addition, blood pressure and pulse rate (PR) measurements provide information about the psychophysiological status of patients as a result of a sympathetic activity. In this study, the investigators aimed to evaluate the emotional responses of patients who were considered by the healthcare providers and relatives of patients as an 'unconscious patient' by using electrophysiological tests.