sensory gating phenomenon. Other areas of the brain associated with sensory gating include the amygdala, striatum, medial prefrontal cortex, and mid-brain dopamine cell region (GABAergic neurons only). Research on sensory gating has been primarily occurring in cortical areas where the stimulus is consciously identified because it is a less invasive means of studying sensory gating. Studies on rats also show the brain stem, thalamus, and primary auditory cortex play a role in sensory gating for auditory stimuli. Techniques for measurement Paired-click paradigm The paired-click paradigm is a common non-invasive technique used to measure sensory gating, a type of event-related potential. For normal sensory gating, if a person hears a pair of clicks within 500 ms of one another, the person will gate out the second click because it is perceived as being redundant. Evidence of the gating can be seen in the P50 wave, occurring in the brain 50 ms after the click. Low values of the P50 wave indicate that sensory gating has occurred. High values of the P50 wave indicate a lack of sensory gating. Individuals with schizophrenia only reduce the amplitude of S2 by 10–20%, whereas individuals without schizophrenia reduce the amplitude of S2 by 80–90%. Other techniques Electroencephalography (EEG) and magnetoencephalographies (MEG) are used to measure brain responses and are common techniques for studying sensory gating. One type of EEG measure used for sensory gating research is the event-related potential (ERP). EEG research on sensory gating shows that gating starts almost immediately after receiving a stimulus. Positron emission tomography (PET) studies have shown that an increased need to gate information is accompanied by increased engagement of the thalamus. P50 wave testing is one of many auditory event-related potential studies. Sensory gating deficits and mental illness Schizophrenia A large interest in sensory gating research is directed at improving deficits among people diagnosed with schizophrenia. People with schizophrenia often have deficits in gating the neuronal response of the P50 wave, which is why P50 is the most widespread method of diagnosis. The test is conducted through having the patients hear two uniform sounds with an interval of 500 milliseconds. While the patients are hearing the sound, an EEG cap is used to measure the brain activity in response to those sounds. A normal subject shows a decrease in brain activity while hearing a second sound, while a subject showing equal brain activity to the first sound is more