The disruption and dissolution of directed forgetting : Inhibitory control of memory

In a series of directed-forgetting (DF) experiments it was found that inhibition of a to-be-forgotten (TBF) list could be disrupted by a secondary task and completely abolished by a concurrent memory load during second to-be-remembered (TBR) list learning. Similarly, inhibition was found to be wholly abolished when the TBF and TBR list were strongly associated but not when weakly associated. These findings suggest that inhibition in the DF procedure depends on how powerfully the second TBR list competes in memory with the representation of the TBF list. When the representation of the TBR list is impoverished or when it is too similar to the TBF list then competition is weak and inhibition is as a consequence weak or does not occur at all. © 2000 Academic Press A fundamental problem facing any memory system is how to select individual items from a range of related items, all of which are (equally) available for recall. For instance, recalling the comments of person A from yesterday’s meeting rather than those of B and C, recalling fact X rather than the related facts Y and Z, or, more mundanely, simply recalling where one parked one’s car today as opposed to yesterday or the day before (Bjork, 1989) all require resolution of competing responses in memory. This problem may be especially acute for very recently encoded knowledge, much of which may be in a highly accessible state for some limited period after encoding. Short-term retention, over a period of hours or possibly longer, of a very detailed record of experience may occur because it is not possible at the moment of encoding to fully determine what should be retained