MBS 93-11
Retention Curves of Artificial and Natural Memory: Tight and Soft Models
Tarow Indow
Theoretical equations were fitted to retention curves of two kinds:
artificial memories in traditional experiments and natural memories concerning
past episodes and experiences. the former includes data of classical experiments
by Ebbinghaus, Strong, Luh, etc., and retention curves on muscular skill.
The latter includes memories of street names, city landmarks, Spanish learned
in school, etc., in Bahrik's studies as well as retention curves generated
from a study of Warrington and Sanders (1971), which range up to 40 years
for subjects of 20 to 60 years old when memory was input. Two kinds of
model are discussed: one is based upon differential equation of an assumed
underlying process and the other upon two extreme statistics about life
span of memory-supporting cues for elements. an element becomes unretrievable
when either one cue or all the cues are lost. Goodness of fits and changes
of the parameters are discussed in relation to the nature of memory, the
method of testing memory, and the age of subjects.