His recovery of memory was progressive and spontaneous, where after several months the amnesia was limited to the two years preceding the trauma. This was a classic case of PRA. [57]
GC was a 38 year old accountant that was found in a town square unable to remember anything about himself and unaware of where he was and how he got there. He was eventually able to recall basic information about himself and his family, but could not recall emotionally charged autobiographical events pertaining to the last 7 years of his life. Within 3–4 days, it was determined that his autobiographical amnesia was clearly and strictly selective for professional events, as he could remember everything that was not related to his job. It was ultimately learned that the job had created severe emotional stress and anxiety due to the extreme hours that triggered a sudden fugue state. He was eventually able to recover most of his memories minus a single work event where he had stolen money from the company. This was a classic case of psychogenic amnesia. [57]
AF is a 15-year-old boy who hit his head and lost consciousness. He could not remember anything but was able to play songs on the piano, showing that his procedural memory was still intact. He gradually recovered some memories within the first 2–3 days but had autobiographical amnesia as well as significant memory loss for famous public facts and events for the 2 years prior to the injury.
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. Damage can be limited to the CA1 field of the hippocampus, causing very limited RA for about one to two years. More extensive damage limited to the hippocampus causes temporally graded amnesia for 15 to 25 years. Another study suggests that large medial temporal lobe lesions, that extend laterally to include other regions, produce more extensive RA, covering 40 to 50 years. These findings suggest that density of RA becomes more severe and long-term as the damage extends beyond the hippocampus to surrounding structures. The common studied causes of RA do not always lead to the onset of RA. It may even be that in some cases both conscious feigning and unconscious processes are at play. Traumatic brain injury (TBI) or post-traumatic amnesia
Traumatic brain injury (TBI), also known as post-traumatic amnesia, occurs from an external force that causes structural damage to the brain, such as a sharp blow to the head, a diffuse axonal injury, or childhood brain damage (e.g., shaken baby syndrome). In cases of sudden rapid acceleration, the brain continues moving around in the skull, harming brain tissue as it hits internal protrusions.TBI varies according to impact of external forces, location of structural damage, and severity of damage ranging from mild to severe.