<unk>  or callosal syndrome is a type of disconnection syndrome when the corpus callosum connecting the two hemispheres of the<unk>  is severed to some degree. It is an association of symptoms produced by disruption of, or interference with, the connection between the hemispheres of the<unk> . The surgical operation to produce this condition (corpus callosotomy) involves transection of the corpus callosum, and is usually a last resort to treat refractory epilepsy. Initially, partial callosotomies are performed; if this operation does not succeed, a complete callosotomy is performed to mitigate the risk of accidental physical injury by reducing the severity and violence of epileptic seizures. Before using callosotomies, epilepsy is instead treated through pharmaceutical means. After surgery, neuropsychological assessments are often performed. After the right and left<unk>  are separated, each hemisphere will have its own separate perception, concepts, and impulses to act. Having two<unk> s" in one body can create some interesting dilemmas. When one<unk>  patient dressed himself, he sometimes pulled his pants up with one hand (that side of his<unk>  wanted to get dressed) and down with the other (this side did not). He also reported to have grabbed his wife with his left hand and shaken her violently, at which point his right hand came to her aid and grabbed the aggressive left hand. However, such conflicts are very rare. If a conflict arises, one hemisphere usually overrides the other. When<unk>  patients are shown an image only in the left half of each eye's visual field, they cannot vocally name what they have seen. This is because the image seen in the left visual field is sent only to the right side of the<unk>  (see optic tract), and most people's speech-control center is on the left side of the<unk> . Communication between the two sides is inhibited, so the patient cannot say out loud the name of that which the right side of the<unk>  is seeing. A similar effect occurs if a<unk>  patient touches an object with only the left hand while receiving no visual cues in the right visual field; the patient will be unable to name the object, as each cerebral hemisphere of the primary somatosensory cortex only contains a tactile representation of the opposite side of the body. If the speech-control center is on the right side of the<unk> , the same effect can be achieved by presenting the image or object to only the right visual field or hand. The same effect occurs for visual pairs and reasoning. For example, a patient with<unk>  is shown a picture of a chicken foot and a snowy field in separate visual fields and asked to choose from a list of words the best association with the pictures. The patient would choose a chicken to associate with the chicken foot and a shovel to associate with the snow; however, when asked to reason why the patient chose the shovel, the response would relate to the chicken (e.g. "the shovel is for cleaning out the chicken coop").
Split-brain
Neural clique
Saint Hubert's Key
Cortical homunculus
Surgisphere
Neurodiversity
Curette
Carbuncle