certain specific instances while others more). Focal, isolated, and pure retrograde amnesia Focal isolated, and pure retrograde amnesia are terms used to describe a pure form of RA, with an absence of anterograde amnesia (AA). In addition, Focal RA in particular, has also been used to describe a RA situation in which there is a lack of observable physical deficit as well. This could be described as a psychogenic form of amnesia with mild anterograde and retrograde loss. A case study of DH revealed that the patient was unable to provide personal or public information, however there was no parahippocampal or entorhinal damage found. Individuals with focal brain damage have minimal RA. Isolated RA is associated with a visible thalamic lesion. Consistent with other forms of RA, the isolated form is marked by the inability to recall past information. Pure retrograde amnesia (PRA) refers to the behavioral syndrome that is characterized by the inability to retrieve remote information in the face of a normal ability to learn new information, with no other ecological or psychometric evidence of cognitive impairment. It should not be confused with brief periods of peritraumatic amnesia that are common in mild concussive head traumas. The findings of pure retrograde amnesia have helped form the dissociation between mechanisms for RA and AA. Several studies have found numerous causes for PRA like vascular diseases, head traumas ranging from mild to severe, encephalitis, as well as purely psychological conditions and totally unidentifiable etiologies. Most people who have PRA can function normally and learn new information A pure form of RA is rare as most cases of RA co-occur with AA. A famous example is that of patient ML. The patient's MRI revealed damage to the right ventral frontal cortex and underlying white matter, including the uncinate fasciculus, a band of fibers previously thought to mediate retrieval of specific events from one's personal past. During consolidation, the hippocampus acts as an intermediate tool that quickly stores new information until it is transferred to the neocortex for the long-term. The temporal lobe, which holds the hippocampus, entorhinal, perirhinal and parahippocampal cortices, has a reciprocal connection with the neocortex. The temporal lobe is temporarily needed when consolidating new information; as the learning becomes stronger, the neocortex becomes more independent of the temporal lobe. Studies on specific cases demonstrate how particular impaired areas of the hippocampus are associated with the severity of RA.