Differential maintenance of auditory and tactile working memory: evidence from the cross-modal selective interference task

The maintenance of working memory (WM) representations relies on both specific and general components. The specific component is related to distinct WM subsystems with different domains or modalities, while the general component is shared across the whole WM process, regardless of domain and modality. However, the mechanisms underlying the contributions of these two components remain unclear. To address this question, we examined the effects of sensory modalities while controlling for the influence of the domain of stimuli. Specifically, we examined this question through the selective interference task with information from the same domain (frequency information) but different modalities (tactile & auditory). In Experiment 1, participants (n = 25) were required to complete a primary task involving auditory frequency WM and a secondary task involving frequency discrimination for either the same modality (auditory) or a different modality (tactile) during the retention of memory items. Results showed that the accuracy of the auditory primary task was equally affected by auditory and tactile secondary tasks, indicating that auditory frequency maintenance relies on general resources. Experiment 2 (n = 23) was identical to Experiment 1, with the exception that tactile modalities were used during the primary task. Results showed no significant difference in tactile primary task accuracy. However, reaction times for both the primary and secondary tasks were significantly shorter under the same modality, indicating the distinct mechanisms for the maintenance of auditory and tactile frequency WM. These findings indicate that both modality general and specific components contribute to auditory and tactile WM storage for frequency information.