In neuropsychology, a phenomenon in which a person is able to detect a stimulus from one side if it is presented separately, but does not notice it when a competing stimulus from the opposite side appears at the same time. It is more often observed with lesions of the parietal lobe, especially the right hemisphere, and is often combined with spatial negligence. Extinction can manifest itself in visual, tactile, or auditory modalities and reflects a disturbance of attention rather than primary sensory processing.