Auditory Memory-Search

Abstract

A methodology for an auditory analogue to the visual memory-search task first reported by Sternberg in 1966 was developed to test the effects of processing load with high levels of practice using auditory stimuli and to examine the generality of hypotheses of processing mode based on visual memory search. Simultaneously presented pure tones discriminable by frequency and location were used in a single-presentation, search task. The number of tones in the memory and test sets, the presence or absence of a match, and categorical differences between targets and distractors were varied in a fixed-set procedure using consistent mapping of stimuli to responses such that tones used in the memory set were never used as distractors. Results demonstrated that subjects were able to perform the search tasks even when as many as four pure tones were presented simultaneously. Under conditions in which target and distractor ensembles were composed of a mixture of high and low tones, accuracy and mean reaction time continued to show load effects after extensive practice. Under conditions in which targets were categorically different from distractors, low tones versus high tones, load effects were nonsignificant even at the beginning of practice. Implications for search-task paradigms and for a theory of automaticity are discussed. Parameters that relate automatic and controlled processing to an underlying quantitative continuum ate emphasized.