PURPOSE: Chronic obstructive pulmonary disease (COPD) is a condition characterized by progressive airway obstruction and recurrent attacks. Multisystem involvement with extra-pulmonary manifestations has been seen in COPD patients. Numerous neurological involvement like cerebrovascular diseases, polyneuropathies, motor neuron diseases and cognitive impairement has been reported in COPD patients. Cognitive dysfunction is usually associated with hypoxia or hypercapnia in COPD patients. To our knowledge there is no study about sensory gating in COPD patients. We performed p50 test to COPD patients and we investigate sensory gating in COPD patients.