Can episodic memory be a (narrow) cognitive ability?

Shing, Y. L . et al. Episodic memory across the lifespan: the contributions of associative and strategic components.Neuroscience and Behavioral Reviews, 34 (2010) 1080-1091http://www.sciencedirect.com/science/article/pii/S0149763409001687

Episodic memory is memory for life events that we experienced in a specific place at a specific time.  Autobiographical memory is composed of episodic memory and semantic knowledge about ourselves and about things that took place in the world during our lifetimes.

Can episodic memory be a (narrow) cognitive ability?  Maybe so!  To do that, episodic memory has to fulfill a few conditions suggested by Schneider .  In this post we will discuss one of these conditions:  developmental across the lifespan.

All cognitive abilities identified hitherto (Fluid ability, Comprehension Knowledge, Processing Speed etc.) develop across the lifespan.   What about episodic memory?

Shing and his colleagues argue that the ability to remember lifetime events as personal experiences begins at about the age of six.  Episodic memory continues to improve from age six to adolescence, and deteriorates in elderly people.

There are different ways to recall life events (like the ways we retrieve semantic knowledge):  recognition ("Have you been to the Eifel tower?"), free recall ("Which sites in Paris did you visit?"), or cued recall ("Did you visit places in Paris from which there is a panoramic view?")

Recognition is the easiest form of remembering.  It requires less cognitive effort of searching in memory.  Free recall and cued recall require more cognitive effort and strategies for retrieval of information from memory.  Recognition develops in children at an earlier age than retrieval and cued recall.   Older adults show poorer performance than younger adults on memory tasks, with the difference in performance being largest in free recall, followed by cued recall and recognition.

 When we attempt to retrieve information from episodic memory we have to be able to discriminate between events we know had happened (but we did not experience them, since they did not happen to us personally), imagined events, and events that we'd actually experienced.  In other words, we have to be able to determine the source of the memory (something someone told us, something we imagined or something that happened to us).   We determine the memory source by retrieving contextual information from memory (what we did before and after the event, who else was there, what the physical environment in which it took place looked like etc.)

Children under six are poor at judging whether they imagined a specific activity or really performed it.  Old people are also poor at judging the source of memory.

Another distinction is between  recollection and familiarity.  There are events that we know happened to us, but we don’t experience them as episodic memory.  We don't have an experience of ourselves in these events.  We are familiar with these events but don't recollect them.

 The development of recollection extends into adolescence, whereas familiarity matures earlier during childhood.  When old people retrieve episodic memories, they rely more on familiarity and less on recollection.  They remember less specific details of the event, experience themselves less in the event itself, but can tell about the event since they are familiar with it and know they experienced it.

Strategies for organizing and retrieving episodic memories develop throughout the lifespan.  Coginitive control processes, such as elaborating and organizing the memory content, validating it with contextual knowledge, controlling the memory content (what content belongs to which event), creating a search strategy for a specific event in autobiographical memory– all these are active both during encoding and during retrieval.  Children younger than 6 are poor at organizing the memory content, even when they are instructed to do so.  Only by the end of elementary school, children begin to organize information they learn without being prompted to do so, and to activate strategies for memory search and retrieval.  Older people are poor at activating efficient strategies both during learning and during encoding and retrieval.

To summarize, we see that episodic memory is present by the age of six and deteriorates in old age.  Young children and old people have difficulty identifying the memory source more than adolescents or adults.  Small children and old people rely more on familiarity than on recollection when they recall episodic memories.  Efficient strategies for storage and retrieval develop during elementary school and deteriorate in old age. 

This is how episodic memory fulfills one of the conditions for being a cognitive ability – a pattern of development across the lifespan. 

Does it satisfy other conditions?  I hope to write about that in the future.