Summary: From Ebbinghaus to Encoding

Hermann Ebbinghaus began a long tradition in memory research with his work on memory for nonsense syllables, published in 1883. Ebbinghaus wanted to study memory of things learned for the first time, uncontaminated by the effects of associations from past experience. His nonsense syllables were intended as new, meaningless stimuli.

Ebbinghaus documented the forgetting curve, which shows rapid loss of information from memory shortly after a retention interval begins, followed by progressively slower rates of forgetting. This forgetting curve holds true for many types of material, although one researcher (Linton) found that memory for personal experiences followed more of a straight line, showing a steady loss.

Tests of recall include serial learning (which requires the subject to preserve the order of stimuli) and free recall (which requires recall of items in any order). Free recall is the least constrained type of memory, because the order of items recalled is left up to the subject.

Tests of recognition differ from tests of recall because, in recognition tests, the subject is presented with the to-be-remembered-item and asked whether or not it is familiar. The yes/no method is less accurate than the forced choice method, because if you ask for a yes or no recognition judgment, people adopt different levels of confidence for saying, "Yes." If you require a forced choice between alternatives, then people must pick one and only one item as the old item they recognize. Forced choice testing removes the effects of response bias and proves to be a sensitive test of recognition memory. Using pictures as stimuli, with forced-choice recognition testing, recognition memory appears to have "almost limitless" capacity.

The new era of memory research that emphasized encoding also drew psychologists' attention to constructed nature of memory. It is far more efficient to store the code for producing a memory rather than storing the whole experience. If the memories we experience are like cakes, then the memory traces we store in our brains are like recipes. Each time we re-live a memory, we are making a fresh construction, and it is possible to introduce errors into the reconstruction. False memories can feel completely genuine. False memories are a problem for therapists, who cannot easily tell whether a memory of childhood trauma is accurate, and for lawyers, who encounter memory distortions in the courtroom.


Write to Dr. Dewey at psywww@gmail.com.

Don't see what you need? Psych Web has over 1,000 pages, so it may be elsewhere on the site. Do a site-specific Google search using the box below.

Custom Search

Copyright © 2007 Russ Dewey