Context effects in short-term memory: confirmatory evidence from recall of visually presented lists

Thirty-two subjects had tests of serial recall of visually presented nine-digit lists which were either presented in a single block of trials (constant context) or in between lists of much longer length (variable context). Other variables were vocalization-during-presentation versus silent memorization (within subject) and order of recall (between subjects). The results showed a negative effect of variable context on the penultimate serial positions in the case of silent memorization but not in the case of vocalization. Context had no effect on the first and middle parts of the list, which confirms earlier results with auditorily presented lists (Bunt 1976), but which disagrees with the original evidence from Crowder (1969). Subjects preferred forward recall in the case of silent memorization and echobox recall in the case of vocalization during presentation, irrespective of context.

The results are discussed within the framework of the notion of precategorical acoustic storage (PAS) and of positional retrieval cues. The latter theory seems to provide a better and more comprehensive account.