Integrated cross-domain object storage in working memory: Evidence from a verbal–spatial memory task

Abstract

Working-memory theories often include domain-specific verbal and visual stores (e.g., the phonological and visuospatial buffers of Baddeley, 1986), and some also posit more general stores thought to be capable of holding verbal or visuospatial materials (Baddeley, 2000; Cowan, 2005). However, it is currently unclear which type of store is primarily responsible for maintaining objects that include components from multiple domains. In these studies, a spatial array of letters was followed by a single probe identical to an item in the array or differing systematically in spatial location, letter identity, or their combination. Concurrent verbal rehearsal suppression impaired memory in each of these trial types in a task that required participants to remember verbal–spatial binding, but did not impair memory for spatial locations if the task did not require verbal–spatial binding for a correct response. Thus, spatial information might be stored differently when it must be bound to verbal information. This suggests that a cross-domain store such as the episodic buffer of Baddeley (2000) or the focus of attention of Cowan (2001) might be used for integrated object storage, rather than the maintenance of associations between features stored in separate domain-specific buffers.

Keywords:

• Working memory
• Focus of attention
• Episodic buffer

Acknowledgments

This research was carried out in partial fulfilment of the requirements for the Doctor of Philosophy degree at the University of Missouri, supported by National Institute of Mental Health (NIMH) Grant 1F31MH074205–01A2 and a University of Missouri Department of Psychological Sciences Dissertation Research Grant. Thanks to Nelson Cowan, Jeffery Rouder, and Randi Martin for helpful comments.