Recognition memory for tactile sequences.

In three experiments participants were required to compare the similarity in item order for two temporally separated sequences of tactile stimuli presented to the fingers of the hand. Between-sequence articulatory suppression but not tactile interference impaired recognition accuracy (Experiment 1), and the null effect of tactile interference was not due to the second tactile sequence overwriting the sensory record of the first sequence (Experiment 2). Experiment 3 showed that compared to a condition where the second sequence was presented in the tactile modality only, recognition was enhanced when the second sequence was seen presented either to the hand or on a diagrammatic representation of a hand. A final experiment showed that the effects of Experiment 1 were replicated when the underside of the forearm was used for stimulus presentation, suggesting that the data are not idiosyncratic to the first method of presentation. The pattern of results suggests memory for a sequence of tactile stimuli involves the deployment of strategies utilising a combination of verbal rehearsal and visuo-spatial recoding rather than relying solely on the retention of sensory traces. This is taken to reflect limitations in both the capacity and duration of tactile sensory memory.