Retrieval of autobiographical memories: The mechanisms and consequences of truncated search.

Five studies examined the extent to which autobiographical memory retrieval is hierarchical, whether a hierarchical search depends on central executive resources, and whether retrieving memories that are "higher" in the hierarchy impairs problem-solving ability. The first study found that random generation (assessed using a button-pressing task) was sensitive to changes in memory load (digit span). The second study showed that when participants fail to retrieve a target event, they respond with a memory that is higher up the hierarchy. The third study showed that memory is more generic only when participants use low imageable cues under cognitive load. The final two experiments showed that experimental manipulation of memory specificity affects problem solving (MEPS performance). The data are consistent with Conway and Pleydell-Pearce's hierarchical retrieval model of autobiographical memory, and suggest that overgeneral memory in nonclinical participants is associated with reduced executive capacity only when retrieval is "top-down" (generative).