Goal-directed access to mental objects in working memory: The role of task-specific feature retrieval

摘要

In the present study, we examined the hypothesis of task-specific access to mental objects from verbal workingmemory. It is currently assumed that a mental object is brought into the focus of attention in working memory bya process of object selection, which provides this object for any upcoming mental operation (Oberauer, 2002).We argue that this view must be extended, since the selection of information for processing is always guidedby current intentions and task goals. In our experiments, it was required that two kinds of comparison tasks beexecuted on digits selected from a set of three digits held in working memory. The tasks differed in regard to theobject features the comparison was based on. Access to a new mental object (object switch) took consistentlylonger on the semantic comparison task than on the recognition task. This difference is not attributable to objectselection difficulty and cannot be fully accounted for by task difficulty or differences in rehearsal processes.The results support our assumptions that (1) mental objects are selected for a given specific task and, so, areaccessed with their specific task-relevant object features; (2) verbal mental objects outside the focus of attentionare usually not maintained at a full feature level but are refreshed phonologically by subvocal rehearsal; and (3) ifmore than phonological information is required, access to mental objects involves feature retrieval processes inaddition to object selection.