Amnesia (Retrograde)

Real and Not So Real Retrograde Amnesia

Retrograde amnesia (RA) is the impairment in memory retrieval for information acquired normally before the event that caused the amnesia (Cohen 2011). RA varies in its degree and temporal extent while also varying in its aspects of memory impairment. Memory for facts, personal events, world knowledge, skills, personality, and personal identity are specific aspects of memory that may be affected (Cohen 2011). In the case of Clive Wearing, almost all aspects of his memory of the remote past are lost except for his ability to play the piano exceptionally well (Wilson 1995). This gives us an idea of just how independently our brain stores the different types of information and how diverse amnesiac patients can be.

There are two types of RA, organic and functional amnesia. Organic RA is cause by structural brain damage and varies in temporal extent and is associated with some kind of anterograde amnesia. Organic RA can extend from a couple weeks as is seen in traumatic brain injuries, to several decades as seen in the movie The Music Never Stopped, where the main character, Greg, had organic RA that extended back decades. It is also typically graded due to memory consolidation mechanisms that increase the ability to hold on to older memories while more recent memories are more likely to be affected by brain disruptions.

Organic RA is also typically graded due to memory consolidation mechanisms. The brain has an increased hold on remote memories, while more recent memories are not as strongly held onto and are thus more likely to be lost due to brain disruptions. Temporally limited and temporally extensive organic RA's differ in the length of the time period of memory loss, but are similar in that the more recent past is worse than the more remote past memory. Temporally limited RA can be seen in individual's who have had bilateral ECT treatments in which graded memory loss extends back 1-3 years (Cohen 2011). Temporally extensive RA can be seen in individuals suffering from Korsakoff's disease where they have graded memory loss extending several decades (Cohen 2011). In the article "The lost Mariner", the patient, Jimmie G., had lost several decades of his life due to Korsakoff's disease to the point where he still believed he was a teenage boy.

Another type of organic RA is temporally graded in its recovery. This type is typical of traumatic brain injuries, which begin as a temporally extensive RA and slowly recovers remote memories working towards the more recent memories. As stated in lecture, most brain trauma ends up with RA extending back less than a week in 80% of patients. Although this is one of the most common types of organic amnesia, it is often one of the most inaccurately portrayed in the media. In moves such as the Bourne Identity, and the Addams Family, the main character suffers a loss of identity with virtually no anterograde amnesia that would be expected of an organic RA. They also show selective memory loss instead of general memory loss such as Jason Bourne's loss of identity but perfectly preserved skills as well as Gomez's ability to regain world knowledge despite his identity loss.

The ability of Gomez to regain his knowledge by a simple hit on the head is also not accurate since memory is regained gradually over time and not suddenly by such means as more trauma. In the movie Overboard, the character Joanna recovers from her functional retrograde amnesia suddenly when her real husband shows up at her doorstep to reclaim her. Memory does not recover in such a way.

The symptoms from the two examples in the previous examples are actually representative of symptoms seen in functional RA. Functional RA is caused by a psychological trauma where there is no structural damage to the brain or anterograde amnesia