Misleading postevent information: Testing parameterized models of integration in memory

Abstract

A classic series of experiments by Loftus, Miller and Burns (1978) showed that a person's recollection of an event can be changed by misleading postevent information. Several hypotheses accounting for this effect have been proposed. Loftus' hypothesis of destructive updating claims that the original memory is destroyed by the postevent information. The coexistence hypothesis asserts that the older memory survives but is rendered inaccessible through a mechanism of inhibition or suppression. The non-conflict hypothesis simply accounts for the effect by claiming that subjects can only be misled if they did not encode or if they forgot the original event. These three hypotheses were modelled with the help of all-or-none probabilistic event trees. An experiment was conducted in order to test the three models and to assess parameter values. The experiment followed the classic Loftus paradigm. We suggested to some subjects that they had seen a stopsign, whereas in fact they had seen a traffic light. The misleading postevent information resulted in poorer reproduction of traffic light. Later, all subjects were asked whether they could remember the color of the traffic light, even if they believed they had seen a stopsign. The results showed that subjects who received the misleading post-event information were at least as good at recalling the color of the traffic light as subjects who did not receive misleading information. The no-conflict model accounts well for the obtained results, although the two other, less parsimonious, models cannot be entirely rejected.