Positional uncertainty in the Brown-Peterson paradigm.

Since McGeoch's (1932) influential article, no accounts of long-term memory have invoked decay as a cause of forgetting. In contrast, multiple accounts of short-term memory (STM) invoke decay, with many appealing to results from the Brown-Peterson paradigm as offering support. Two experiments are reported that used a standard Brown-Peterson task but which scored the data in 2 ways. With traditional scoring (was the entire 3-letter consonant trigram recalled?) performance decreased with increasing delay. With immediate serial recall scoring (e.g., was the first letter recalled first, was the second letter recalled second?), standard position error gradients (Experiment 1), and protrusion gradients (Experiment 2) were observed. That is, when the first letter of the consonant trigram was not recalled first, it was more likely to be recalled second than last. In addition, if a letter from a previous list was mistakenly recalled in a later list, it most likely retained its original position. The presence of such gradients is inconsistent with claims of decay but is predicted by SIMPLE, a local distinctiveness model of memory. Moreover, the presence of such gradients is consistent with the claim that forgetting in the Brown-Peterson paradigm follows the same principles observed in other memory tasks.