EASE OF ACCESS TO LIST ITEMS IN SHORT-TERM MEMORY DEPENDS ON THE ORDER OF THE RECOGNITION PROBES

We report data from four experiments using a recognition design with multiple probes, to be matched to specific study positions. Items could be accessed rapidly, independent of set-size, when the test order matched the study order (forward condition). When the order of testing was random, or backward, or in a pre-learned irregular sequence (re-ordered conditions), the classic Sternberg result was obtained, response times were slow and increased linearly with set size. A number of explanations for forward-condition facilitation were ruled out, such as the predictability of the study order (Experiment 2), the predictability of the probe order (Experiment 1), the covariation of study and test orders (Experiments 1, 2, 4), processes of probe encoding and perception that did not rely on STM access (Experiments 1, 2, 4), specific support of the forward condition by articulatory processes (Experiment 3), or condition-dependent strategic differences (Experiment 4). More detailed analyses demonstrated that fast forward responses could not be accounted for by the effects of input position and output position that modulated random responses, effects that did account for the slower responses of the re-ordered conditions (Experiments 1, 3, 4). A final analysis of probe-to-probe transitions as a function of encodin