One implication of the source monitoring perspective is that it may be possible for a person to discriminate true from false memories. Although memory characteristics associated with both true and false memories may
overlap, in general there may be differences between them. If people at- tend to the relevant characteristics, they may learn to accurately distin- guish true from false memories.
Several researchers investigated differences in ratings of the character- istics associated with true and false memories. For example, both Norman and Schacter (1997) and Mather, Henkel, and Johnson (1997) studied the characteristics associated with true and false memories of words from a word list. Participants were given lists of words semantically related to a nonpresented word—the critical lure (Deese, 1959; Roediger & McDer- mott, 1995). These types of lists reliably result in high levels of false recog- nition for the critical lure. Norman and Schacter (1997) and Mather et al. (1997) asked participants to rate their recollections for the true words and for the false critical lure. In general, the critical lure memories had lower ratings on many sensory characteristics.
Johnson et al. (1997) used a similar methodology to investigate the possi- ble differences in patterns of brain activation when individuals accurately recognized true items and falsely recognized critical lures. They found evi- dence for differences in brain activation when the types of items were grouped—that is, if the participants were presented with sets of true items, critical lures, and distracter items at test. When the items were intermixed, however, they found no differences in brain activation between accurately recognizing true items and falsely recognizing critical lures. The findings on discriminating between true and false memories of words are mixed. Other researchers have investigated discriminations of true and false memories of autobiographical experiences. Conway et al. (1996) used a di- ary method to study false autobiographical memories. Two participants kept records of daily experiences for several weeks. In addition, the partic- ipants wrote down things that did not occur, and an experimenter created false events based on the structure of the participants’ lives. On a recogni- tion test, the participants identified many of the false events as personal experiences. Compared to the true events, however, the participants were less likely to claim remembering the false events. Instead the participants more frequently reported guessing that the false events were true and claiming to know, without remembering, that the events happened.
In their investigation of false childhood memories, Pezdek et al. (1997) studied the descriptions that participants constructed of the true events and the false event. They found that people provided shorter and less detailed descriptions of the false events. Both of these findings suggest that false memories may be less detailed and therefore discriminable through various source monitoring judgments—such as the remem- ber–know judgment.
Hyman and Pentland (1996) also examined ratings of true and false memories in their investigation of false childhood memories. They, how-
ever, made one additional important comparison. Like others (Conway et al., 1996; Pezdek et al., 1997), they found that when false memories were compared to childhood experiences that people were able to remember in the first and subsequent interviews, the false events were rated lower on measures of sensory qualities. The additional comparison made was to re- covered memories. In their study, participants occasionally failed to re- member a true event in the first interview and then claimed to remember the event in subsequent interviews. Ratings of these recovered true mem- ories indicated less sensory clear memories than the true memories that the participants recalled in the first and subsequent interviews. More im- portantly, there was no discernible difference between the recovered and false memories. This distinction may be important in the recovered mem- ory versus false memory controversy.
The results of studies investigating the discrimination of true from false memories are mixed. In some cases memories are rated differently and in others the differences are harder to discern. The comparisons that are used are crucial. When false memories are compared to memories that people have always had, the false memories appear less clear. When false memories are compared to recovered memories, however, no differences are apparent. The comparison of false to recovered memories is critical for applied concerns. Hyman (1999) argued that discriminating true from false autobiographical memories may be difficult for people to do. In gen- eral, people believe their memories. Furthermore, they seldom receive re- liable feedback on the veracity of their recollections. There are not external records for most personal experiences. The external records that exist are often other people’s recollections. Without feedback, people may not learn which autobiographical memories are reliable and which are not. If peo- ple receive reliable feedback, they may learn to differentiate between true and false memories.
CONCLUSION
The research of false childhood memories has extended the work on eye- witness memory errors. In response to suggestion, people not only change features of events, but they also create complete memories of self-in- volving, emotional events. Clearly, the contexts in which people are asked to remember their childhoods will sometimes lead to erroneous recall. False memories are created when events are made plausible, when people are encouraged to construct images and narratives, and when people erro- neously claim the source to be a personal memory.
In many interview contexts, false events are made plausible. Authors of popular press books identify personality characteristics and psychological
problems that are indicative of certain childhood experiences. Therapists may provide similar feedback. Individuals may participate in groups that share current characteristics and childhood experiences—such groups im- ply that new members also share the same experiences. In addition, hear- ing stories and imagining experiences increases the availability of such ideas and the subjective plausibility of experiences. Through a variety of channels, false events are made to appear plausible.
Once people accept the plausibility of a false event or a misleading sug- gestion, they construct a new image and narrative that includes the erro- neous information. In false childhood memories, many activities encour- age the construction of false narratives. For example, when people make connections between the self and the false event, the constructive process begins. When they later consider the false event, they construct an event that combines both the suggested information with general self-knowl- edge to create a new memory (Hyman & Billings, 1998; Hyman et al., 1995). Other activities, such as imagining the experience and journaling can also lead to the construction of the false memories. A crucial aspect of this construction is the impact of the false suggestion on other aspects of the event. Many studies of false childhood memories have found that par- ticipants elaborate on suggested events. These elaborations are consistent with the false event, but are most likely a reflection of an individual’s gen- eral event knowledge and personal experiences. False memories extend beyond the simple implantation of the suggested event.
Once an individual has constructed a memory of a plausible childhood event, that person must still claim the memory as a personal recollection. The more effort that an individual devotes to developing the image, the more likely the individual is to eventually claim the image is remembered (Goff & Roediger, 1998; Hyman et al., 1998; Hyman & Pentland, 1996). In addition, there are probably social factors that influence the source moni- toring decision.
At the least, the research on false childhood memories demonstrates how memory errors can be introduced via misleading suggestions. More- over, these three processes of plausibility judgments, memory construc- tion, and source judgments can be applied to traditional studies of eye- witness suggestibility. For over two decades now, researchers have been concerned with the underlying explanation of misinformation acceptance: Does the misinformation replace the original information in memory, or do people lose track of the source of the misinformation and claim the misinformation was part of the original experience? The growing empha- sis has been on source monitoring explanations for the misinformation ef- fect. This emphasis, although helpful in explaining the misinformation ef- fect, has overlooked other aspects of eyewitness suggestibility.
For example, in traditional investigations of suggestibility in eyewit- ness memory, plausibility was not investigated. The false suggestions are implicitly, and sometimes explicitly, designed to be plausible: not too many false suggestions, not too large of suggestions, use a reliable source, and so on. How people judge the plausibility of misleading information is not well understood. A few studies have shown that the source of mis- leading suggestions affects the rate of errors (Dodd & Bradsaw, 1980; Greene, Flynn, & Loftus, 1982). This could be because the source influ- ences whether people accept the suggestions as plausible.
Most recent investigations have focused on whether people include the specific suggestion in their recollection. This will miss the constructive as- pect of human memory. If false information becomes part of a memory, then it should influence other aspects of the memory when the memory is reconstructed. Loftus and Palmer (1974) demonstrated this possibility in memories of an automobile accident. People’s understanding of the sever- ity of a car accident was altered by the way they asked how fast the cars were going. They asked some people “how fast when they hit each other,” whereas they asked others “how fast when they smashed into each other.” The verb change affected estimates of speed and can be described as a typ- ical misinformation effect. In a subsequent interview, Loftus and Palmer asked if the participants recalled seeing broken glass (there was none). Those who were asked about smashing cars more often recalled seeing broken glass. The changed understanding of speed affected other aspects of the event when it was eventually reconstructed. If researchers focus only on the critical suggested item, by following source monitoring theory, then they will miss the overall reconstructive nature of human memory.
Research on false childhood memories is also important for under- standing autobiographical memory. People accept misleading sugges- tions and construct false childhood memories because autobiographical memory is generally constructive. In many ways, “life is an ongoing mis- information experiment” (Hyman & Pentland, 1996). People are con- stantly encountering others’ views of experiences. Through conversation, people share their memories. In the midst of this exchange of memories, people may adopt information from other individuals into their own memories (Hyman, 1999). Furthermore, two individuals may interpret a remembered event in very different ways. Over time, one individual may adopt another’s interpretation. In addition, some of our memories could be stories that we have heard told many times and that we now believe we remember. This may lead to the creation of entire experiences. The past is an ongoing creation—a construction built with our memories and the cur- rent social context.
To the extent that the self is defined in terms of our memories (Green- wald, 1980; James, 1890; Neisser, 1988), the self is also malleable. One way
we understand ourselves is through the narrative we tell about the past. When this narrative is altered, the self is altered as well (Oakes & Hyman, in press). The person who discovers a traumatic memory in therapy may develop a new understanding of the past. For the effect on the self- concept, it doesn’t matter if the memory is true or false—the self may change in either case. Sarah, the woman who disclosed her experience with recovered memories in response to a class discussion, is an unfortu- nate example. She found that her understanding of her past, her self, and her relationships with her family were altered by the recovered memories of abuse. Unfortunately, she can not differentiate whether the memories are true or if the memories are false.
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When children are asked to describe what they have seen, heard, or expe-