LOCUS OF THE IRRELEVANT SPEECH EFFECT IN SHORT-TERM-MEMORY

The impairment by irrelevant speech on immediate, serial recall of visually presented items may be interpreted as an effect at either encoding or storage. Experiment 1 presented speech at input, rehearsal, or recall stages of a serial recall task and showed impairments of equal magnitude at both input and rehearsal. Experiment 2 demonstrated that articulatory suppression modified this impairment equally at both stages, but there was no independent impairment by speech. Experiment 3, using written rather than keyed recall, replicated these findings, with an additional independent impairment by speech, suggesting that the mode of response influenced the rehearsal strategy adopted. The experiments lend unequivocal support to the storage interpretation of the irrelevant speech effect.