The Brain and Memory: Learn It 3—Amnesia

amnesia

Amnesia is the loss of long-term memory that occurs as a result of disease, physical trauma, or psychological trauma.

Psychologist Endel Tulving (2002) and his colleagues at the University of Toronto studied K.C. for years. K.C. suffered a traumatic head injury in a motorcycle accident and then had severe amnesia. Tulving writes,

the outstanding fact about K.C.’s mental make-up is his utter inability to remember any events, circumstances, or situations from his own life. His episodic amnesia covers his whole life, from birth to the present. The only exception is the experiences that, at any time, he has had in the last minute or two. (Tulving, 2002, p. 14)

There are two common types of amnesia: anterograde amnesia and retrograde amnesia (Figure 1).

Appropriate alternative text can be found in the caption for this photo.
Figure 1. This diagram illustrates the timeline of retrograde and anterograde amnesia. Memory problems that extend back in time before the injury and prevent retrieval of information previously stored in long-term memory are known as retrograde amnesia. Conversely, memory problems that extend forward in time from the point of injury and prevent the formation of new memories are called anterograde amnesia.

anterograde amnesia

Anterograde amnesia is commonly caused by brain trauma, such as a blow to the head. With anterograde amnesia, you cannot remember new information, although you can remember information and events that happened prior to your injury. The hippocampus is usually affected (McLeod, 2011). This suggests that damage to the brain has resulted in the inability to transfer information from short-term to long-term memory; that is, the inability to consolidate memories.

Anterograde Amnesia in the movies

Dory, from the movies “Finding Nemo” (2003) and “Finding Dory” (2016), is an example of a movie character with anterograde amnesia. Dory is a friendly and lovable regal blue tang fish. She has a kind heart but often struggles with remembering things. Anterograde amnesia affects her ability to form new memories and retain information for an extended period. Dory’s condition leads her to forget things quickly, including recent events, names, and important details. Despite her challenges, Dory remains optimistic and resilient, relying on her friends to help her navigate the world and overcome obstacles. The movies showcase Dory’s journey to find her family and the adventures and friendships she forms along the way, emphasizing the importance of perseverance and friendship.

Remember that the prefix anter- or antero- means “in front” or “before”. In anterograde amnesia, people are able to recall memories from before the injury, but cannot commit new memories to long-term memory.

Many people with this form of amnesia are unable to form new episodic or semantic memories, but are still able to form new procedural memories (Bayley & Squire, 2002). This was true of H. M., who was discussed earlier. The brain damage caused by his surgery resulted in anterograde amnesia. H. M. would read the same magazine over and over, having no memory of ever reading it—it was always new to him. He also could not remember people he had met after his surgery. If you were introduced to H. M. and then you left the room for a few minutes, he would not know you upon your return and would introduce himself to you again. However, when presented with the same puzzle several days in a row, although he did not remember having seen the puzzle before, his speed at solving it became faster each day (because of relearning) (Corkin, 1965, 1968).

retrograde amnesia

Retrograde amnesia is loss of memory for events that occurred prior to the trauma. People with retrograde amnesia cannot remember some or even all of their past. They have difficulty remembering episodic memories.

You can also think of the prefix retro- as “old” (e.g., that lamp from the 70’s is so retro) to help remind you that retrograde amnesia deals with forgetting old memories.

What if you woke up in the hospital one day and there were people surrounding your bed claiming to be your spouse, your children, and your parents? The trouble is you don’t recognize any of them. You were in a car accident, suffered a head injury, and now have retrograde amnesia. You don’t remember anything about your life prior to waking up in the hospital. 

Retrograde amnesia in the movies

In “The Bourne Identity” (2002) and its subsequent sequels, the main character Jason Bourne, portrayed by Matt Damon, experiences retrograde amnesia. Jason Bourne is found floating in the ocean with two gunshot wounds and no memory of his identity or past. Retrograde amnesia affects his ability to recall his previous life, including his name, personal history, and skills. As the story unfolds, Bourne discovers that he possesses exceptional combat and espionage abilities, indicating prior training and involvement in covert operations. However, he struggles to remember the details of his past and his role within the secret organization he was part of. Throughout the film series, Bourne embarks on a quest to uncover his true identity, gradually piecing together fragments of his past while evading dangerous enemies. The concept of retrograde amnesia adds intrigue and mystery to the character, as he fights to reclaim his lost memories and understand the truth about his own existence.

However, for real-life sufferers of retrograde amnesia, like former NFL football player Scott Bolzan, the story is not a Hollywood movie. Bolzan fell, hit his head, and deleted 46 years of his life in an instant. He is now living with one of the most extreme cases of retrograde amnesia on record. 

Watch this video about Jing Wu and her experience with retrograde amnesia. These led her to create the MindReset blog to help others through similar types of experiences or other traumas.