What we may not realize as much are the times when our memory works splendors. Just imagine – we can remember the time when we fell down and scraped our knee on concrete at seven. We can remember that World War I happened between 1914 and 1918, and, perhaps less impressively, that the current president of the United States is Barack Obama. Although these seem like diminutive abilities, brain-injured patients with amnesia show us that memory is extraordinary and that memory deficits have a great impact on our ability to function in daily life.
One of the divisions of long-term memory, our permanent store of facts and knowledge, is declarative memory. Declarative memory consists of semantic and episodic memory. Semantic memory consists of general knowledge, like “George Washington was the first president of the United States.” On the other hand, episodic memory encompasses the events we have experienced at a specified time and place. Semantic and episodic memory are important concepts to understand when talking about brain-injured patients because, depending on the injury, semantic memory could be affected, but not episodic memory, and vice versa.
Many studies have shown that the sense of self is also closely related to long-term memory (Baddeley, 1988; Conway and Pleydell-Pearce, 2000). There is a great amount of evidence for the self-reference effect (SRE). Simply put, there seems to be an advantage of processing to-be-remembered information in terms of how it relates to ourselves – our personality traits, our social identity roles, our unique experiences and the emotions felt during those experiences. A recent finding is that the SRE extends to memory-impaired populations, such as older adults and brain-injured patients (Dulas, Newsome and Duarte, 2011). The SRE can be used to help strengthen memory by prompting an individual to connect a piece of information to their personality traits or to a past experience.
A variation of this self-referential strategy was recently studied by Matthew Grilli and Elizabeth Glisky at the University of Arizona, and is known as self-imagination. In the study, 15 brain-injured patients and 15 healthy controls were shown 24 trait adjectives, one after the other, and then immediately prompted to recall aloud the adjectives they could remember. The same participants were asked to carry out this memory task under five different instructions prompts – they were asked to think of words that rhymed with the traits, the definitions of the traits, an event when they acted out the trait (episodic self-referencing), how well the trait described them (semantic self-referencing) and, in the self-imagining condition, themselves acting out the trait in their mind.
For both groups, the study found that the self-imagining technique resulted in better recall compared to all other conditions. In a separate task, the participants were asked to rate how well each of the traits displayed described them. Based on this measure, the patients were found to have only remembered more self-descriptive traits in the self-imagining and semantic self-referential conditions, and not in the episodic self-referential condition. This suggests that perhaps self-referential strategies need to target a specific type of processing in patients with acquired brain injury.
Why might the self-imagination technique work better than other mnemonic strategies? One possibility is that self-imagination is flexible and allows us to tap into several episodic memories at once, and not just a single event. The technique also allows one to tap into semantic self-knowledge by encouraging an individual to think about whether this action would fit their social role or personality.
What this finding means for memory-impaired populations is that there may be a more targeted and efficient way of improving memory. Because the imagined events are associated with one's self-schema, self-imagination could ultimately lead to treatments for other psychological conditions, too, such as emotional disorders. Furthermore, this sets the stage for further investigations into the common mechanism of semantic self-referencing and self-imagination. In the meantime, you can try this technique out yourself. Maybe imagining yourself as one of the framers of the Constitution will help you remember some of its amendments for history next semester.
Further Reading (opens in a new window):
- Clinical Psychological Science's inaugural issue, January 2013: http://cpx.sagepub.com/content/current
- Levels of Processing: http://www.simplypsychology.org/levelsofprocessing.html
- Amnesic Patient, K.C. (Semantic memory intact, but not episodic memory) http://en.wikipedia.org/wiki/KC_(patient)
Grilli, M.; Glizky, E. "Imagining a Better Memory: Self-Imagination in Memory-Impaired Patients." Clinical Psychological Science 1(1) (2013): 93-99.