Source Monitoring

You see things, hear descriptions of other things, watch fictionalized films, and have dreams. Your life sometimes depends on your ability to determine whether a memory is "real" and whether you can trust its contents. Given that memories differ so much in their age, completeness, modality, sensibility, and other features, you must be able to use whatever is available when making source decisions.

We've found that people use a variety of memory features to make source monitoring decisions. For example, they can base their decision about whether they have encountered an object by evaluating their memory for shape information. If, for example, a pumpkin was seen previously, people are likely to mistakenly think that they'd seen a basketball, which shares many of the pumpkin's physical features. In a series of studies examining various features that could be brought to bear in source decisions, we have found that people use not only physical information, but also category, identity, linguistic label, perspective-based schematic information, and statistical covariation in source monitoring. Although these classes of information may differ in their salience or diagnosticity, they all normally provide a rational means for determining source, and so decisions based upon their use should lead to high accuracy under normal circumstances.

We've also shown the influence of a systematic but irrational influence on source monitoring: the imposition of one's desires and emotional biases on source monitoring decisions. Even when a source decision is no more likely to be accurate, wishful thinking can lead to source attributions that serve a self-protective function. In several studies involving sources that differ in reliability, we've shown that people tend to remember the reliable source as having given desirable statements and the unreliable source as having made undesirable ones. We have shown that the wishful thinking bias takes place at retrieval, and we have shown that a single wish can distort an entire database of otherwise independent memories. The following describes some of our more recent projects.


Current and Recent Projects in Source Monitoring

  1. How social intelligence impairs memory. (with Sarah Barber and with Makiko Naka and Hiroki Yoshimura, Hokkaido University, Japan)
    • The more similar the candidate sources are to each other, the harder it is to identify a memory’s source. In general, memories originating from perception (for example, something a partner said) differ in a lot of ways from memories of self-generated events (e.g., something you said). Because of these differences, people can usually determine whether a particular memory was internally or externally generated. We have found, however, that people of high social intelligence (i.e., those who are better at adopting other people’s perspectives or anticipating others’ actions) are poorer at this sort of source monitoring than are people of low social intelligence. Our longer-term goals are to understand the circumstances and consequences of this effect, and to examine its interplay with other interpersonal strategies, tasks, and culture.
  2. Self-reference and wishful thinking. (with Ruthanna Gordon and Sarah Barber)
    • Typically, the way wishful thinking has been demonstrated in our lab is through distortions in source monitoring: People are biased to attribute a message to the source that best suits their desires. For example, a prediction that a good person will succeed at an important endeavor is erroneously attributed to the source who has a track record of high (as opposed to low) accuracy. This project examines the wishful thinking effect specifically as it relates to self-relevant information. A slightly different pattern emerges for these circumstances as compared with other-relevant circumstances. Consistent with the classic self-relevance effect in memory, people's memory for source is superior to other-relevant situations when the content is interpreted as being self-relevant. This, however, does not protect memory from the distorting effects of wishful thinking, which biases people's responses in cases where source is not remembered. This basic effect interacts with task circumstances in sensible ways. For example, warnings can eliminate the bias associated with wishful thinking, and increased delay between learning and test eliminates the self-relevant facilitation.
  3. Mood and the heuristic use of source cues (with Mike Greenstein and Shanna Allen)
    • When they can't remember where a specific memory comes from, people tend to play the odds. For example, a law-related statement probably came from the candidate source who is an attorney, rather than from the doctor. We have been examining the degree to which cognitive style (in the form of reliance on heuristics such as these) is determined by one's mood. Consistent with previous findings by Bodenhausen and others that when people are angry, their judgments become more heuristic, and when they are sad, their judgments are based on more careful analysis, we find that memory judgments follow a similar pattern. We are currently examining the degree to which such effects generalize to other heuristic phenomena in source monitoring.
  4. Observer-Based Components of Weapon Focus Effects (with Julie Riederer)
    • In the classic weapon focus effect, an object in a coherent scene can produce patterns of attention and memory that favor a weapon or surprising object, to the detriment of other details. A growing literature has established how aspects of the object or scene can drive these effects. Our work investigates the roles of both stable characteristics and current expectations of the observer in attending to potentially threatening scenes. Although the weapon focus effect is typically considered to be a stimulus-driven phenomenon, this work addresses how the factors of interpretation and trait predisposition might mediate the effect.
  5. Familiarity matching in source monitoring. (with Chui-Luen Vera Hau, Jen Beck, Stephanie Caradonna, Chaz Sylvester, and Ahmed Belazi)
    • Individual sources tend to produce redundant content (e.g., George Bush utters multiple messages over time about Iraq, the deli guy tells you on different days about available coffee flavors, and your friend from California uses the word "gnarly" a lot). We can apply a rational bias to our memories, based on the fact that not only will frequently encountered messages feel more familiar than infrequently encountered ones, but it's likely that a given frequently encountered (and thus familiar-feeling) message will have come from a frequently encountered source. We find that people do indeed have a strong bias to attribute familiar-feeling messages to more frequent sources, even when the experience of familiarity is artificially inflated at test through priming (flashing the word briefly, below the perceptual threshold, before presenting it for judgment). The familiarity-matching heuristic, as we have dubbed it, turns out to be quite sophisticated; people use it only when it would be sensible to do so.
  6. Prototype effects in source monitoring. (with Chui-Luen Vera Hau and Jessica Klug)
    • Memory for one object can influence whether people believe they'd seen or only imagined another object. For example, seeing one category member (e.g., shirt) increases the likelihood that you will later mistakenly believe you'd seen another, imagined, member (e.g., pants). This work investigates whether the classic prototype effect found for memory (whereby, for example, an apple has more stable memory characteristics than a grapefruit) can be extended to source monitoring. We have found that prototypes are indeed treated differently from non-prototypes in judging whether the quality of memory features indicates a real or imagined source.
  7. Use of top-down cues in source monitoring. (with Jessica Klug)
    • When they encounter information, people often make additional inferences, which they encode along with features of what they had indeed encountered. We've been investigating how these inferences are used in source monitoring, and we've found that people can rely on cues that didn't occur in the remembered situation to judge where the situation had been experienced. By using well-established effects from other fields, we can manipulate the informativeness of these cues, and thus manipulate people's source monitoring performance. In one set of studies, we capitalized on the out-group homogeneity effect of social psychology, whereby people tend to consider members of their in-group (e.g., young adults) as having high variance on many features (e.g., athleticism, intelligence, friendliness), while they consider out-group members (e.g., elderly adults) as being more homogeneous on the same features. If people tend to create models of different people they learn about, complete with instantiated features, then we should create in-group sources that are fairly different from each other and out-group sources that are harder to differentiate. Through a single sentence that introduced fictitious characters as being either 20 years old or 80 years old, participants will create memories that either facilitated or hampered source monitoring ability. This phenomenon also occurs for non-social sources and demonstrates a broad tendency that people have to impose extraneous features on memories that are used to judge where the memories came from.

Some Relevant Papers

Henkel, L. A., & Franklin, N. (1998). Reality monitoring of physically similar and conceptually related objects. Memory & Cognition, 26, 659-673.


Henkel, L. A., & Franklin, N. (1998). Comments on Murnane & Bayen's "Measuring memory for source: Some theoretical assumptions and technical limitations." Memory & Cognition, 26, 678-680.


Henkel, L. A., Franklin, N., & Johnson, M. K. (2000). Cross modal source monitoring confusions between perceived and imagined events. Journal of Experimental Psychology: Learning, Memory, & Cognition, 26, 321-335.


Geraci, L., Franklin, N., & Beck (2003.) Linguistic label and identity in source monitoring. Memory, 12, 571-585.


Gordon, R., Franklin, N., & Beck, J. (2005). Wishful thinking and source monitoring. Memory & Memory & Cognition, 33, 418-429.


Gordon, R., Gerrig, R. J., & Franklin, N. (2009). Qualitative Characteristics of Memories for Real, Imagined, and Media-Based Events. Discourse Processes, 46, 70-91.


Barber, S., Gordon, R., & Franklin, N. Self-relevance and wishful thinking: Facilitation and distortion in source monitoring.


Barber, S. J., Franklin, N., Naka, M., & Yoshimura, H. How higher social intelligence can impair memory.


Franklin, N., Greenstein, M., & Allen, S. Anger simplifies memory-based decisions.


Franklin, N., & Klug, J. Reliance on inferred features when making source attributions.


Franklin, N., Hau, C.-L. V., Caradonna, S., Beck, J., Sylvester, C., & Belazi, A. Familiarity matching in source monitoring.