Psychological Research: The Eternal Sunshine of the Mundane Mind

In this post, I would like to talk about memory and offer some examples of its portrayal in science fiction.

Research psychologists have a great deal to say about human memory, and while we know little about memory in absolute terms, academic psychology (and related disciplines) has, in the last few years, made great progress towards advancing our knowledge about what memory actually is, how it works, and how we help people whose memories have been impaired developmentally or through trauma.

One aspect of memory that attracts writers of fiction for its dramatic potential is amnesia. Note, however, that the type of amnesia most frequently portrayed is properly termed retrograde amnesia. Let's look at some of the types.

Retrograde amnesia:
A difficulty in recalling experiences prior to the onset of amnesia. The character Jason Bourne from the film The Bourne Identity is an example of this form of memory loss.

Antereograde amnesia:
A difficulty in consolidating new experiences. Typically, sufferers of this type of amnesia can recall only those experiences laid down before the traumatic (physical or psychological) event.

Lacunar amnesia:
A difficulty in recalling information relating to a specific event. Joel Barish had specific memories erased from his brain in the film Eternal Sunshine of the Spotless Mind (remember the name of the memory-wiping company?).

Global amnesia:
A complete failure of memory for experiences. New experiences are not consolidated and old experiences cannot be recalled or recognised. Leonard Shelby from the film Memento suffered from global amnesia. He could neither recall autobiographical information (instead he had to read it from tattoos) nor lay down new memories (instead he took Polaroids).

These forms of amnesia, while interesting in themselves, have provided clues about how memory works. First of all, the apparatus of memory appears to be divided into a short-term component and a long-term component. We're sure that this is a categorical distinction because short-term memory (STM) can be damaged independently of long-term memory (LTM) and vice versa. For example, in the case of Clive Wearing, hippocampal damage destroyed the 'bridge' between his STM and LTM; he is forced to live in a permanent present.

Secondly, the content of LTM memory appears to be divided into semantic information (Lima is the capital of Peru), episodic (yesterday I had eggs for breakfast), and procedural (how to ride a bike or drive a car). There is compelling evidence that these forms of knowledge are distinct. Thus the portrayal of Leonard Shelby's character in Memento is quite plausible: he has not forgotten some semantic information (he knows how to check in to a hotel) and his procedural knowledge appears intact (he can drive a car), but his episodic memory (of himself and his wife) is damaged.

Science fiction and other forms of literature have concentrated on amnesia-related memory problems, but there is another, rarer memory condition in which the sufferer cannot forget. The Russian mnemonist Shereshevsky was diagnosed late in life with a condition known as synaesthesia, in which his senses would combine. Thus he would 'see' smells and 'taste' sounds. For him, everyday experience was so memorable that he found it almost impossible to forget things that happened to him. Was this such a bad thing? Well, if he read a sentence of prose the sensations blooming with each word would make it impossible for him to read a piece of fiction.

Further links:

Short-term memory: A demonstration

The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information

Memory: In Our Time

The Journal of Memory and Cognition