Without surreptitious rehearsal, information in short-term memory decay

Abstract

Reitman (1971) found that subjects could retain three words perfectly for 15 sec while detecting tones in noise and supposedly avoiding rehearsal. These results were taken to indicate lack of support for the decay principle of STM. Two studies reported here test two assumptions in the Reitman study: that 100% recall reflects not a ceiling effect but the absence of forgetting, and the lack of disruption of interpolated detection performance indicates lack of rehearsal. Major results indicated that (1) the 1971 study did involve a ceiling effect; (2) tonal detection is measurably disrupted when subjects rehearse; and (3) when subjects detect equally well in the retention interval as in a control interval they forget 33% of what they can recall immediately, and when they detect syllables instead of tones, they forget about 44% more. There is clear evidence for both decay and simple interference in STM.