Age differences in the rate of processing in short-term memory.

A probe-recognition task compared the speed and accuracy of visual, phonemic, and semantic recognition processes in younger and older adults. Each trial consisted of the sequential presentation of 10 words at a rate of either 350, 700, or 1400 msec per word. Following each study list, a probe word was given that could be identical to any word in the preceding study list or a homonym or a synonym. The two age groups were equivalent in their ability to identify recently presented identical words, homonyms , and synonyms. Age differences, however, were observed in the speed of access to information, and these differences were greatest on tasks requiring retrieval of semantic information from the secondary memory component of short-term memory.