Erin Morrow

Imagine watching an action movie in the theater. The main character is a bank teller who finds herself cornered in a robbery. A man with a black ski mask darts to the counter and points a handgun at her forehead. “Put the cash in the bag, and don’t ask questions,” he orders. The teller agrees, and the police arrive at the scene shortly after to interview her about the details of the crime (see Loftus et al., 1987 for a similar example). She finds that she can easily remember the perpetrator’s firearm, and the sound of the trigger being drawn – but when questioned about more external details, she struggles. Was he joined by any accomplices? Were there any unusual cars in the parking lot when the robbery took place? How many customers were in line? Her recollection is hazy, and everything seems to have blurred together. Why was the teller’s memory excellent for the details of the crime that were immediately at hand, but poor for the surrounding information? What can memory science tell us about this phenomenon, and what does it mean for finding justice?

Emotional memories: are all created equal?

First, it is helpful to note that memory for emotional events is generally more vivid, confident, and accurate than memory for neutral events (e.g., Hamann, 2001; Heuer & Reisberg, 1990; Talarico & Rubin, 2003). In other words, you’ll likely remember a robbery better than a routine bank transaction. Here, emotion is thought of in two main ways – valence (how negative or positive you feel) and arousal (how strongly you feel, regardless of the direction). Although the debate rages on about whether valence or arousal is more important for memory benefits, the clearest enhancement appears to come from one’s arousal level during the original experience, rather than valence (Kensinger & Corkin, 2004). Indeed, both negative and positive events can enjoy memory benefits (Adelman & Estes, 2013), perhaps given that they meet a minimum arousal level (i.e., evoke a ‘strong enough’ response; Canli et al., 2000; Szőllősi, Á., & Racsmány, 2020).

However – as brilliantly laid out by Williams, Ford, and Kensinger (2022) in a review paper on emotional memory research – emotion is not a universal memory enhancer. That is, not every aspect of an emotional memory is necessarily vivid, confident, and accurate. Many researchers have proposed different versions of this same idea within the last 25 years. Some suggest that emotional items act as ‘attention magnets’ by narrowing focus away other items (Reisberg & Heuer, 2004; Laney et al. 2004) or are ‘tagged’ with attentional priority (Mather & Sutherland, 2011), while others say that emotional events spur ‘tunnel memory’ (Safer et al., 1998) or that more ‘central’ or ‘gist’ elements are better remembered (Adolphs et al., 2001; Kensinger et al., 2005) (Williams, Ford, & Kensinger, 2022). Regardless of the particulars, it is clear that not all aspects of emotional memories are created equal.

The weapon focus effect: then and now

Perhaps no idea makes this more convincing or socially-relevant than the weapon focus effect, originally proposed by psychologist Elizabeth Loftus and others (1979; 1987). In an early demonstration of this effect, the researchers had 36 participants view two slideshows, in which either a gun was drawn or a check was presented at a fast-food restaurant. The participants then received a recognition memory test, in which they were shown four items at a time and were told to choose which was present in the slideshow. The participants were then asked to select the perpetrator from a line-up of 12 individuals. The authors found that when participants viewed the slideshow with the gun, they had superb memory for details about the gun itself. However, importantly, the participants demonstrated slightly poorer memory for other features of the scenario and for the perpetrator in the line-up (Loftus, Loftus, & Messo, 1987). This finding is similar to our main character’s ability to remember information about central details (like the gun), but hardly any surrounding details. It also hints that our memory for more peripheral aspects of emotional events may not always be reliable. Indeed – although the effects in this initial study were weak, and its definition of what qualifies as a ‘central detail’ is limited – several studies have offered further evidence of memory outcomes similar to this weapon focus effect.

One such study, which will be shortened for clarity, involved the cooperation of 200 participants. These participants were divided into groups that viewed a slideshow in which a man holding either a knife or a newspaper was shown stealing a woman’s purse. At one point during the slideshow, the object was aimed directly at the camera. Besides these objects, the slides contained both central details (for example, the color of the offender’s shirt) and peripheral details (for example, a parked car in the background). After viewing the slideshow, the participants were also given misinformation about one central and one peripheral detail. Finally, each group received a recognition memory test, in which they were asked to choose which item out of three alternatives was present in the original slideshow. The author found that the group that was shown the knife correctly remembered more central details and fewer peripheral details than the group shown the newspaper. Interestingly, the group shown the knife slideshow appeared to be more susceptible to misinformation about a peripheral detail, claiming something in the background was present when, in reality, it wasn’t. These findings demonstrate that an emotionally arousing context (i.e., the scenario involving the knife) enhanced memory for more central details and weakened memory for more peripheral details. Peripheral memory was also more likely to be influenced by false information in the emotional context (Saunders, 2009).

Another interesting study considered the effect of gender stereotypes on the weapon focus phenomenon. In this experiment, 127 participants watched a video of either a man or a woman hiding in a car before robbing two other individuals. The offender was also holding either a handgun or a CD disk, and the participants verified that they believed a handgun was more closely associated with males, while CDs were gender-neutral. Additionally, all of the participants answered a series of free recall (open-ended) and forced-choice (yes/no) memory questions about both the offender’s physical appearance and the object they were holding. The author found a classic weapon focus effect; that is, the group that was shown the handgun had poorer memory for the offender’s physical appearance than the group shown the CD. Additionally, the authors found that memory was even poorer when the woman held the handgun. This result suggests that violating our expectations in this way captures our attention, and causes an even more exaggerated ‘narrowing’ of memory. Thus, the weapon focus effect appears to be sensitive to attentional effects from what neuroscientists might call ‘prediction error,’ a rough analogy for surprise (Pickel, 2009).

Although these studies are more recent than Loftus’s foundational work, you may note that they are still over a decade old (indeed, how many people still use CDs?). However, the weapon focus effect and similar memory effects continue to explored in the memory literature. Notably, a handful of research articles in the past 5 years have explored how alcohol use (e.g., Harvey & Sekulla, 2021) and how long someone is exposed to the emotional item (e.g., Mansour, Hamilton, & Gibson, 2017) influence weapon focus. These studies are just a few examples of expanding our reach beyond the more simplistic origins of research on this memory phenomenon.

From the laboratory to the courtroom

Perhaps foreshadowed by the use of police lineups as memory tests in this line of work, it is clear that the weapon focus effect and similar memory effects have potential consequences in broader society. From the beginning, Elizabeth Loftus and others described this effect as important for understanding eyewitness testimony (Loftus, 1979; Loftus, Loftus, & Messo, 1987). In particular, the findings described above may lend credibility to claims that central details in an emotional event are recalled more accurately, but may also call into question memory for its peripheral details (for example, certain physical characteristics of the defendant, accomplices, or others in the surroundings).

So, what should we do with this knowledge? How does this affect our beliefs about the accuracy of eyewitness memory? Should the weapon focus effect influence how we educate our judges and jurors? As for the last question, the answer is likely ‘yes.’ A 2011 survey of 1,500 people in the United States showed that many Americans falsely believe that memory functions like a video camera (i.e., capturing and remembering each moment as it really was), that memories do not change over time, and that the confidence of a single eyewitness can provide enough evidence to make a conviction (Simons & Chabris, 2011). All of these statements can be debunked using the findings of basic memory research. In particular, evidence from the weapon focus effect suggests that certain details of events with a central emotional item or feature – a defining characteristic of much criminal activity – may not be remembered accurately. Therefore, eyewitnesses may not always have the backing of science to support their memory for details like the victim’s clothing, or people or items in the background of the environment in which the crime took place. In this respect, their memory might be more similar to looking through a straw than through the lens of a video camera. Of course, this is not to mention the fading and the distortion of the memory representation over time. Healthy skepticism is merited.

However, it is important to note that our legal system and its criminal proceedings are not isolated from social context. Recent sociocultural movements, such as the ‘#MeToo’ movement,  called for us to believe victims of sexual misconduct. In truth, we are situated within societies that have long undervalued and cast doubt on the memories of vulnerable individuals and populations. Not long ago was the confirmation hearing of Supreme Court Justice Brett Kavanaugh, in which the accuracy of Dr. Christine Blasey Ford’s memory for Kavanaugh’s alleged sexual violence was vigorously interrogated. This is not to mention the difficulties faced by those with intersectional identities – for example, Black women and disabled people of color – and the ways in which science has historically excluded these groups from participating in and creating scientific knowledge. It is critical for scientists and memory researchers to both communicate the current state of the science clearly and honestly and thoughtfully consider the social context of their science as they contribute to legal discourse.

Despite these complex issues, it is clear that the weapon focus effect makes important contributions to our understanding of memory function, particularly during highly emotional events like those examined within our legal system. It seems the best advice might be to ‘proceed with caution’ – and surely as memory science continues to provide insights into what and how we remember emotional experiences, we will get closer to ensuring truth and justice.

References

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Talarico, J. M., & Rubin, D. C. (2003). Confidence, not consistency, characterizes flashbulb memories. Psychological Science, 14(5), 455-461.

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Harvey, A. J., & Sekulla, A. (2021). Evidence of alcohol induced weapon focus in eyewitness memory. Applied Cognitive Psychology, 35(5), 1263-1272.

Mansour, J. K., Hamilton, C. M., & Gibson, M. T. (2019). Understanding the weapon focus effect: The role of threat, unusualness, exposure duration, and scene complexity. Applied Cognitive Psychology, 33(6), 991-1007.

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