In electroencephalography, the P50 is an event related potential occurring approximately 50 ms after the presentation of a stimulus, usually an auditory click.[1] The P50 response is used to measure sensory gating, or the reduced neurophysiological response to redundant stimuli.
Research has found an abnormal P50 suppression in people with schizophrenia, making it an example of a biological marker for the disorder.[2][3] Besides schizophrenia, abnormal P50 suppression has been found in patients with traumatic brain injury, recreational drug use, and post-traumatic stress disorder.[4]