Recent studies have used measures such as ERPs and fMRI and it is believed that the parietal lobe mediates the internal representation of both body and space. They found that in their sample, a cortical lesion was almost always found in the right parietal angula gyrus region. Patients typically showed damage to the inferior parietal areas of the brain. There can also be preserved function in the superior parietal lobe, even with inferior parietal damage. Parietal regions include some neurons with ipsilateral receptive fields, so that while the representation within one hemisphere emphasizes contralateral space overall, some ipsilateral representation is present also. More specifically, the number of left-hemisphere neurons with visual receptive fields at a particular location decreases monotonically as one considers increasingly peripheral locations in the left visual field, and vice versa in the right hemisphere. This might go some way towards explaining why extinction is more severe after right-hemisphere lesions in people, leaving the patient with just the steep gradient of the intact left hemisphere. Types Tactile Patients with tactile extinction are aware of being touched on a contralesional limb, but seem unaware of similar contralesional touch if touched simultaneously on their ipsilesional limb. In the tactile, extinction occurs in the domains of at the level of the hands, the face-neck, the arms-legs, both in case of symmetrical and asymmetrical stimulations, or between the two sides of a single body-part. Extinguished tactile stimulus does not access consciousness but it may interfere with perception of the ipsilesional one. Considerable processing can still take place prior to the level at which loss of awareness arises. The extinction can also rise in bilateral conditions. In a patient study, bilateral trials with extinction still revealed residual early components over the right hemisphere in response to the extinguished left touches. When somatosensory neural activity in the right hemisphere was reduced in amplitude when compared to the one by right hand stimulation on the left hemisphere. So it can be concluded that tactile extinction is defined in conditions of bilateral stimulation and perhaps unilateral stimulation as well. Extinction arises at a high level of tactile input processing. Visual extinction Visual/spatial extinction, also known as pseudohemianopia, is the inability to perceive two simultaneous stimuli in each visual field. Those who show spatial extinction can detect a single item in both the left and right visual fields but, under certain conditions of bilateral double simultaneous stimulation