been told to him. Other forms of amnesia Other forms of amnesia exist and may be confused with RA. For instance, anterograde amnesia (AA) is the inability to learn new information. This describes a problem encoding, storing, or retrieving information that can be used in the future. It is important to note that these two conditions can, and often do both occur in the same patient simultaneously, but are otherwise separate forms of amnesia. RA can also be an inherent aspect of other forms of amnesia, namely transient global amnesia (TGA). TGA is the sudden onset of AA and RA caused by a traumatic event, however it is short lived, typically lasting only 4 to 8 hours. TGA is very difficult to study because of the patients' quick recovery. This form of amnesia, like AA, remains distinct from RA. Post-traumatic amnesia (PTA) is a state of confusion that occurs immediately following a traumatic brain injury in which the injured person is disoriented and unable to remember events that occur after the injury. Psychogenic amnesia, or dissociative amnesia, is a memory disorder characterized by sudden retrograde autobiographical memory loss, said to occur for a period of time ranging from hours to years. See also Amnesia Anterograde amnesia Dissociative amnesia Scott Bolzan – One of the most severe cases of retrograde amnesia on record References External links Journal of Neuroscience The strange case of Jonathan Overfeld from The State We're In radio show Amnesia