Misinformation effect

The misinformation effect refers to the finding that exposure to misleading information presented between the encoding of an event and its subsequent recall causes impairment in memory.^[1][2] This effect occurs when participants' recall of an event they witnessed is altered by by introducing misleading postevent information.^[3] It is a prime example of retroactive interference, which occurs when information presented later interferes with the ability to retain previously encoded information. Essentially, the new information that a person receives works backward in time to distort memory of the original event.^[2] The misinformation effect has been studied for over 30 years. Elizabeth Loftus is one of the most influential researchers in the field.

The misinformation effect reflects two of the cardinal sins of memory: suggestibility, the influence of others' expectations on our memory and misattribution, information attributed to an incorrect source. Research on the misinformation effect has uncovered concerns about the permanence and reliability of memory.^[4]

Visual display of retroactive memory interference

Basic methods

Loftus, Miller, and Burns (1978) conducted the original misinformation effect study. Participants were shown a series of slides, one of which featured a car stopping in front of a yield sign. After viewing the slides, participants read a description of what they saw. Some of the participants were given descriptions that contained misinformation, which stated that the car stopped at a stop sign. Following the slides and the reading of the description, participants were tested on what they saw. The results revealed that participants who were exposed to such misinformation were more likely to report seeing a stop sign than participants who were not misinformed.^[5]

Depiction of the Loftus et. al (1978) experimental design.

Similar methods continue to be used in misinformation effect studies. Today, standard methods involve showing subjects an event, usually in the form of a slideshow or video. The event is followed by a time delay and introduction of post-effect information. Finally, participants are retested on their memory of the original event.^[6] This original study by Loftus et al. paved the way for multiple replications of the effect in order to test things like what specific processes cause the effect to occur in the first place and how individual differences influence susceptibility to the effect.

Neurological Causes

Recent research points to certain areas of the brain that are especially active when later false memories are retrieved. In one study, participants studied photos while experimenters monitored participants' brain activity using an Functional magnetic resonance imaging (FMRI). Later, in a misinformation phase, participants viewed sentences describing the studied photographs, some of which contained information conflicting with that depicted in the photographs. One day later, participants returned for a surprise item memory recognition test on the content of the photographs. Results showed creation of false memories in that participants reported information that had been presented in the verbal misinformation but not in the photographs.^[7]

Results showed that during the original event phase, increased activity in left fusiform gyrus and right temporal/occipital cortex may have reflected increased attention to visual detail, which was associated with later accurate memory for the critical item(s) and thus resulted in resistance to the effects of later misinformation.^[7] Additionally, neural responses suggest that retrieval of true memories is associated with greater reactivation of sensory-specific cortices (for example, the occipital cortex for vision).^[7]

Susceptibility

It is important to note that not everyone is equally susceptible to the misinformation effect. Individual traits and qualities can either increase or decrease one's susceptibility to recalling misinformation.^[5] Such traits and qualities include: age, working memory capacity, personality traits and imagery abilities.

Age

Several studies have focused on the influence of the misinformation effect on various age groups.^[1] Young children are more susceptible than older children and adults to the misinformation effect.^[1] Additionally, elderly adults are more susceptible than younger adults.^[1]

Working memory capacity

Individuals with greater working memory capacity are better able to establish a more coherent image of an original event. Participants performed a dual task: simultaneously remembering a word list and judging the accuracy of arithmetic statements. Participants who were more accurate on the dual task were less susceptible to the misinformation effect. This, in turn, allowed them to reject the misinformation.^[5][8]

Personality traits

The Myers Briggs Type Indicator is one type of test used to assess participant personalities. Individuals were presented with the same misinformation procedure as that used in the original Loftus et al. study in 1978 (see above). The results were evaluated in regards to their personality type. Introvert-intuitive participants were more likely to accept both accurate and inaccurate postevent information than extrovert-sensate participants. Therefore, it was speculated that introverts are more likely to have lower confidence in their memory and are more likely to accept misinformation.^[5][9] Individual personality characteristics, including empathy, absorption and self-monitoring, have also been linked to greater susceptibility.^[1]

Imagery abilities

The misinformation effect has been examined in individuals with varying imagery abilities. Participants viewed a filmed event followed by descriptive statements of the events in a traditional three-stage misinformation paradigm. Participants with higher imagery abilities were more susceptible to the misinformation effect than those with lower abilities. The psychologists argued that participants with higher imagery abilities were more likely to form vivid images of the misleading information at encoding or at retrieval, therefore increasing susceptibility.^[5][10]

Influential Factors

Time

Individuals may not be actively rehearsing the details of a given event after encoding. The longer the delay between the presentation of the original event and post-event information, the more likely it is that individuals will incorporate misinformation into their final reports.^[6] Furthermore, more time to study the original event leads to lower susceptibility to the misinformation effect, due to increased rehearsal time.^[6]

Source reliability

The more reliable the source of the post-event information, the more likely it is that participants will adopt the information into their memory.^[6] For example, Dodd and Bradshaw (1980) used slides of a car accident for their original event. They then had misinformation delivered to half of the participants by an unreliable source: a lawyer representing the driver. The remaining participants were presented with misinformation, but given no indication of the source. The misinformation was rejected by those who received information from the unreliable source and adopted by the other group of subjects.^[6]

Discussion and rehearsal

The question of whether discussion is detrimental to memories also exists when considering what factors influence the misinformation effect. One particular study examined the effects of discussion in groups on recognition. The experimentors used three different conditions: discussion in groups with a confederate providing misinformation, discussion in groups with no confederate, and a no-discussion condition. They found that participants in the confederate condition adopted the misinformation provided by the confederate. However, there was no difference between the no-confederate and no-discussion conditions, proving that discussion (without misinformation) is neither harmful nor beneficial to memory accuracy.^[11] In an additional study Karns et al. (2009) found that collaborative pairs showed a smaller misinformation effect than individuals. It appeared as though collaborative recall allowed witnesses to dismiss misinformation generated by an inaccurate narrative.^[12]

Discrepancy detection principle

The Discrepancy Detection Principle states that recollections are more likely to change if a person does not immediately detect discrepancies between misinformation and memory for the original event.^[1][13] At times people recognize a discrepancy between their memory and what they are being told.^[14] People might recollect, "I thought I saw a stop sign, but the new information mentions a yield sign, I guess I must be wrong, it was a yield sign."^[14] Although the individual recognizes the information as conflicting with their own memories they still adopt it as true.^[1]If these discrepancies are not immediately detected they are more likely to be incorporated into memory.^[1]

State of mind

Various inhibited states of mind such as drunkenness and hypnosis can increase misinformation effects.^[1] Assefi and Garry (2002) found that participants who believed they had consumed alcohol showed results of the misinformation effect on recall tasks.^[15] The same was true of participants under the influence of hypnosis.^[16]

Other

Most obviously, leading questions and narrative accounts can change episodic memories and thereby affect witness' responses to questions about the original event. Additionally, witnesses are more likely to be swayed by misinformation when they are suffering from alcohol withdrawal ^[12][17] or sleep deprivation,^[12][18] when interviewers are firm as opposed to friendly,^[12][19] and when participants experience repeated questioning about the event.^[12][20]

Reducing the misinformation effect

Arousal after learning

Arousal induced after learning reduces source confusion, allowing participants to better retrieve accurate details and reject misinformation. In a study of how to reduce the misinformation effect, participants viewed four short film clips, each followed by a retention test, which for some participants included misinformation. Afterward, participants viewed another film clip that was either arousing or neutral. One week later, the arousal group recognized significantly more details and endorsed significantly fewer misinformation items than the neutral group.^[21]

If you know it's coming...

Can warning against the misinformation effect enable participants to resist its influence? If participants are warned prior to the presentation of misinformation, they are often able to resist misinformation's influence. However, if warnings are given after the presentation of misinformation, they do not aid participants in discriminating between original and post-event information.^[1]

Psychotropic placebos

Research shows that placebos do, in fact, enhance memory performance. In a 2008 study, participants were given a phoney "cognitive enhancing drug" called R273. When they participated in a misinformation effect experiment, people who took R273 were more resistant to the effects of misleading postevent information.^[22] As a result of taking R273, people used stricter source monitoring because they attributed their behavior to the placebo and not to themselves.^[22]

Implications of the misinformation effect

What are the implications of this effect on our long-term memories and how can we apply the effect to our daily lives?

Original memory

Some reject the notion that misinformation causes any type of impairment of original memories.^[1] Modified tests are used to examine the issue of long-term memory impairment.^[1] In one example of such a test, participants were shown a burglar with a hammer.^[23] They were then presented with post-event information claiming the weapon was a screwdriver. In the standard test condition, participants were likely to choose the screwdriver rather than the hammer. In the modified test condition, participants were not given the choice of a screwdriver, instead they had the option of the hammer and another tool (a wrench, for example). In this condition, participants generally chose the hammer, showing that there was no trace of memory impairment.^[23]

Rich false memories

Rich false memories are researchers' attempts to plant entire memories of events that never happened in participants' memories. Examples of such memories include fabricated stories about participants getting lost in the supermarket or shopping mall as children. Researchers often rely on suggestive interviews and the power of suggestion from family members, known as “familial informant false narrative procedure.”^[1] Around 30% of subjects have gone on to produce either partial or complete false memories in these studies.^[1] There is a concern that real memories and experiences may be surfacing as a result of prodding and interviews. To deal with this concern, many researchers switched to implausible memory scenarios.^[1]

Daily applications

The misinformation effect is seen "in action" on a daily basis. For example, after witnessing a crime or accident there may be opportunities for witnesses to interact and share information. Late-arriving bystanders or members of the media may ask witnesses to recall the event before law enforcement or legal representatives have the opportunity to interview them.^[12] Collaborative recall may lead to a more accurate account of what happened, as opposed to individual responses that may contain more untruths after the fact.^[12]

In addition, while remembering small details may not seem important, they can matter tremendously in certain situations. A jury's percpetion of a defendant's guilt or innocence could depend on such a detail. If a witness remembers a mustache or a weapon when there was none, the wrong person may find themselves on the wrong side of prison bars.^[2]

See also

• Eyewitness memory
• Weapon focus
• Encoding (memory)
• Storage (memory)

References

1. ^ ^{a b c d e f g h i j k l m n o} Loftus, E. (2005). "Planting misinformation in the human mind: A 30-year investigation of the malleability of memory". Learning & Memory 12(4) (4): 361–366. doi:10.1101/lm.94705. 
2. ^ ^{a b c} Robinson-Riegler, B., & Robinson-Riegler, G. (2004). Cognitive Psychology: Applying the Science of the Mind. Allyn & Bacon. p. 313. 
3. ^ Weiten, W (2010). Psychology themes and variations. Belmont, CA: Cengage Learning. p. 292. 
4. ^ Saudners, J.; MacLeod, Malcolm D. (2002). "New evidence on the suggestibility of memory: The role of retrieval-induced forgetting in misinformation effects". Journal of Experimental Psychology 8(2) (2): 127–142. doi:10.1037/1076-898X.8.2.127. 
5. ^ ^{a b c d e} Lee, Kerry (2004). "Age, Neuropsychological, and Social Cognitive Measures as Predictors of Individual Differences in Susceptibility to the Misinformation Effect". Applied Cognitive Psychology 18 (8): 997–1019. doi:10.1002/acp.1075. 
6. ^ ^{a b c d e} Vornik, L.; Sharman, Stefanie; Garry, Maryanne (2003). "The power of the spoken word: Sociolinguistic cues influence the misinformation effect". Memory 11(1) (10.1080/741938170): 101–109. 
7. ^ ^{a b c} Baym, C. (2010). "Comparison of neural activity that leads to true memories, false memories, and forgetting: An fMRI study of the misinformation effect". Cognitive, Affective & Behavioral Neuroscience 10(3): 339–348. doi:10.37958/CABN.10.3.339. 
8. ^ Jaschinski, U., & Wentura, D. (2004). "Misleading postevent information and working memory capacity: an individual differences approach to eyewitness memory". Applied Cognitive Psychology 16 (2): 223–231. doi:10.1002/acp.783. 
9. ^ Ward, R.A., & Loftus, E.F., RA; Loftus, EF (1985). "Eyewitness performance in different psychological types". Journal of General Psychology 112 (2): 191–200. doi:10.1080/00221309.1985.9711003. PMID 4056764. 
10. ^ Dobson, M., & Markham, R., M; Markham, R (1993). "Imagery ability and source monitoring: implications for the eyewitness memory". British Journal of Psychology 84: 111–118. doi:10.1111/j.2044-8295.1993.tb02466.x. PMID 8467368. 
11. ^ Paterson, H.; Kemp, Richard; Forgas, Joseph (2009). "Co-witnesses, confederates, and conformity: effects of discussion and delay on eye-witness memory". Psychiatry, Psychology and Law 16(Suppl 1): S112–S114. doi:10.1080/13218710802620380. 
12. ^ ^{a b c d e f g} Karns, T., Irvin, S., Suranic, S., Rivardo, M., Collaborative recall reduces the effect of a misleading post event narrative (2009). North American Journal of Psychology 11 (1): 17–28. 
13. ^ Tousignant, J.; Hall, David; Loftus, Elizabeth (1986). "Discrepancy detection and vulnerability to misleading postevent information". Memory & Cognition 14(4): 329–338. doi:1987-21001-001. 
14. ^ ^{a b} Loftus, E.; Hoffman, Hunter G. (1989). "Misinformation and memory: The creation of new memories". Journal of Experimental Psychology 188(1): 100-104. doi:10.1037/0096-3445.118.1.100. 
15. ^ Assefi, S.; Garry, Maryanne (2003). "Absolut memory distortions: Alcohol placebos influence the misinformation effect". Psychological Science 14(1): 77–80. doi:10.1111/1467-9280.01422. 
16. ^ Scoboria, A.; Mazzoni, Giuliana; Kirsch, Irving; Milling, Leonard (2002). "Immediate and persisting effects of misleading questions and hypnosis on memory reports". Journal of Experimental Psychology: Applied 8(1): 26–32. doi:10.1037/1076-898X.8.1.26. 
17. ^ Gudjonsson, Hannesdottir, etursson, Bjornsson (2002). "The effects of alcohol withdrawal on mental state, interrogative suggestibility and compliance: An experimental study". Journal of Forensic Psychiatry 13(1): 53–67. 
18. ^ Blagrove, M (1996). "Effects of length of sleep deprivation on interrogative suggestibility". Journal of Experimental Psychology: Applied 2(1): 48–59. 
19. ^ Baxter, J., Boon, J., Marley, C. (2006). "Interrogative pressure and responses to minimally leading questions". Personality and Individual Differences 40(1): 87–98. 
20. ^ Roediger, H., Jacoby, J., McDermott, K. (1996). "Misinformation effects in recall: Creating false memories through repeated retrieval". Journal of Memory and Language 35(2): 300–318. 
21. ^ English, Shaun; Nielson, Kristy A. (2010). "Reduction of the misinformation effect by arousal induced after learning". Cognition 117(2) (2): 237–242. doi:10.1016/j.cognition.2010.08.014. 
22. ^ ^{a b} Clifasefi, S., Garry, M., Harper, D., Engle, R. (2008). "Psychotropic placebos reduce the misinformation effect by increasing monitoring at test". Memory 16(4): 410–419. doi:10.1080/065821080156922. 
23. ^ ^{a b} McCloskey, M.; Zaragoza, Maria (1985). "Misleading postevent information and memory for events: Arguments and evidence against memory impairment hypotheses". Journal of Experimental Psychology 114(1): 1–16. doi:10.1037/0096-3445.114.1.1.