The time course of precueing effects in probed immediate recall

Abstract

In immediate probed recall of a single item from a six-letter list, some of the serial positions (SPs) were precued at various intervals in advance of recall. Rival predictions on effects of precueing were tested, derived from Sanders's (1975) ‘Positional Cueing Theory’ (PCT) and from Raaijmakers and Shiffrin's (1980) SAM theory (‘Search of Associative Memory’). Vocal recall was prompted by a probe signal, which indicated the position of the requested item. The probe started the reaction time (RT) interval and was presented at various intervals after a precue signal (300–900 msec). The precue indicated a subset of serial positions in which the probe would occur. In SAM theory, prerecent items are retrieved by a cue-dependent probabilistic search, while in PCT these items are retrieved by a deterministic inter-item serial search. Since a previous study had shown that precueing preactivates memory retrieval, predictions on how this preactivation would affect recall were derived from PCT and SAM theory. According to PCT, precueing does not change but merely preactivates the retrieval pathway, while in SAM theory, precueing provides additional and more specific retrieval cues. Consequently, PCT predicts only an advantage for latency, while SAM predicts a precueing advantage for both latency and accuracy. Accuracy results clearly supported positional cueing theory instead of SAM theory. Although both theories were in line with the findings on latency, positional cueing theory predicted the particular time course of the precueing effects observed across increasing precue-probe intervals.