Carla C. Chandler

Accessing related events increases retroactive interference in a matching recognition test

Why is memory for a target event impaired by learning related events? Do related events change the trace for the target or hinder retrieval? Target names (e,g., Robert Harris) were shown; experimental items were followed by related names (e. g., Robert Knight) but control items were not. The given names and surnames of the targets were then provided for matching. At short (5-15 min) retention intervals, the control items were matched more accurately than were the experimental items. This retroactive interference (RI) decreased over a 30-min retention interval (Experiment 2), suggesting that the related names did not cause a permanent change in the target trace. More RI occurred at the 30-min retention interval when the related names appeared just before the test (Experiment 3)

Independence between recalling interevent relations and specific events

Four experiments showed independence between recall of specific events and recall of a theme relating the events. A series of statements presented paired comparisons (e.g, A>B, B>C, C>D) that mapped onto a theme (A>B>C>D). The students were then tested successively, being cued by either a feature of a specific event (e.g., What were the two greatest objects ?)

Retrieval processes that produce interference in modified forced-choice recognition tests

Recognition can suffer if the retrieval cues activate more than one trace (e.g., for Flower A and Flower A′). We found evidence for two retrieval processes by examining interference effects in forcedchoice tests (e.g., Did you see Flower A or Flower A″?). Experiment 1 provided evidence of a problem in discriminating between temporally and contextually similar traces that were formed in the study phase. A competitor (Flower A′) interfered more if it was shown in the study phase rather than in the test phase. Experiments 2 and 3 found evidence for a blocking process in recognizing pairs of words (child—apple). A competitor interfered more if it was recent, shown at test rather than at study. This pattern occurred regardless of whether the competitor was similar to the target (child—orange) or dissimilar to it (child—truck). The importance of a particular retrieval process may depend on an item’s representation as well as on the retrieval cues.

Retrieval Processes and Witness Memory

Publisher Summary This chapter addresses several issues concerning retrieval and discusses their potential implications for eyewitness testimony. The chapter discusses the predictions made by the widely embraced encoding specificity principle. This principle asserts that an event will be remembered to the extent that the retrieval cues match the features stored in the memory trace. For example, reinstating the original emotional and physical context should increase the amount that witnesses recall as well as the accuracy of lineup identification, and it does. The principle also predicts that performance should increase if more cues are provided through repeated tests, and if witnesses can convey their responses in the same format (for example, visual, tactile) in which they encoded the event. The chapter then discusses why memory for an event can be reduced by experiencing related events, that is, interference). The evidence that retrieval requires mental resources (effort) is described. Removing distractions should increase performance because all attentional resources can then be focused on retrieval. Effort is needed to use various strategies for recall, such as mentally reinstating the context and generating specific cues.

Item-specific interference caused by cue-dependent forgetting

Memory for A-B word pairs (e.g.,child-apple) was tested by a cued recall test (e.g.,child-app__). Showing an A-C “relative” (e.g.,child-bicycle) reduced recall, especially if it was shown recently and was highly accessible (Experiments 1 and 2). In Experiment 3, a relative facilitated recall if it was semantically similar to the target (A-B′:child-cookies) but interfered if it was semantically dissimilar (A-C:child-fever). The best explanation for these results is that the relative primed features that affected the functional retrieval cue, and that interference occurred if the cue did not match the trace for the target (Martin, 1972). In other words, the interference effects are an example of cue-dependent forgetting. Neither blocking nor a discrimination process can account for these findings, although some evidence for a discrimination process has been found with other materials