Cognitive Skills and Aging

Investigators have used various approaches to the study of adult cognition over the years. Until the 1960s, the associative approach dominated the field. Here, learning was thought to involve the acquisition of stimulus-response (S-R) associations during conditioning. This approach assumed a single underlying memory system, and age-related decline in conditioning was interpreted to mean general systemwide decline. In the 1970s and 1980s, stage theories of learning and memory emerged. These theories focused on stages referred to as encoding, storage, and retrieval. In this approach, encoding is the process of getting information into memory; storage is the manner in which information is kept in memory; and getting information out of memory is referred to as retrieval.

It is clear that learning, forgetting, and memory are closely interrelated. In a sense, without learning there is no memory, and without memory there is no learning. Material is added to memory as learning takes place, and forgetting results from either the loss of information or the inability to recover material from memory. Contemporary cognitive theory assumes a much more central and varied role of memory than was used in previous years (Bäckman, 2001). By the mid-1990s, several major systems of human memory had been identified (see, for example, Hultsch, Hertzog, Dixon, & Small, 1998). Included among these are working memory and several systems of long-term memory, including episodic memory, semantic memory, procedural memory, and prospective memory. Each of these will be examined in turn.