Monday, November 23, 2015

How Does Disgust Affect Memory?

Emotional experiences clearly affect memory.  At the 50th anniversary of the assassination of John F. Kennedy many people shared their memories of where they were when they heard the news that he had been shot.  This event was shocking, and many people reported having vivid memories of that day, even a half-century later.  People who lived through the explosion of the space shuttle Challenger and the events of September 11, 2001 also have significant emotional memories from these dates.  Although these memories may not be 100% accurate, it is clear that people are influenced by the emotional experience at the time.
It is hard to disentangle all of the factors that influence memory in these stressful situations.  They events are surprising.  They are arousing emotional experiences.  They are negative.  They involve a combination of anger, fear, and sadness. 
Because emotional experiences have an influence on memory, controlled laboratory studies have begun to tease apart the elements of emotion that affect what you remember later.
A fascinating set of studies in the November, 2013 issue of the Journal of Experimental Psychology: General by Hanah Chapman, Kristen Johannes, Jordan Poppenk, Morris Moscovitch, and Adam Anderson looked at the way fear and disgust affect memory. 
In one study, the researchers gathered a series of pictures that were disgusting, scary, or neutral.  Disgusting pictures showed things like a cockroach or a picture of a gruesome disease.  Scary pictures showed things like threatening animals or riots.  The neutral pictures were items like coat hangers or coffee makers.  Ratings obtained before the study found that the scary pictures were slightly more arousing overall than the disgusting pictures. 
Each picture was shown for 2 seconds.  When the picture was presented, a line appeared above it or below it.  Participants had to indicate where the line was relative to the picture by pressing a button.  Then, after a delay of either 10 minutes or 45 minutes, participants were asked to recall as many of the pictures as they could.  This memory test was a surprise.  They had not been told that they had to remember the pictures.
Overall, people remembered more of the arousing pictures (both scary and disgusting) than the neutral pictures.  So, pictures that created a negative emotion were more memorable than those that did not.  The disgusting pictures were better remembered than the scary ones.  This difference was particularly strong after a 45-minute delay.  Finally, participants took longer to respond to the location of the line when the pictures were disgusting than when they were scary or neutral.  This finding suggests that people’s attention was more strongly drawn to disgusting pictures than to scary or neutral ones.
Another study in this series found that this effect was also strong even when there was a one-week delay between the initial exposure to the pictures and the test.
Why does this happen? 
Memory for specific items and specific situations is often not important.  When you encounter a coat hanger, you need to know what it is for, so you need to recognize that it is a hanger.  However, it probably does not matter which hanger it is or when you may have seen that particular hanger before.  As a result, we do not really differentiate our experiences of common objects that do not engage our emotions.
When you experience a frightening situation, though, you probably do want to remember it, because you want to be able to avoid that situation in the future.  With disgusting items, there is even more reason to want to remember them. The things we find disgusting are often items that could make us sick.  So, if we encounter them again, we want to know to avoid them.  In this way, memory acts to help keep us safe.

Wednesday, November 11, 2015

Students Don’t Spread Out Their Study Time Enough

I have been around schools my whole life—first as a student and grad student, and for the last 20+ years as a professor.  My own experience as a student was that I tended to ramp up my studying for exams as the test approached.  I might look over some information a week before the exam, but I was mostly likely to wait until a day or two before the exam to really study in earnest.  My observation of students I teach (and my own kids) is that this pattern hasn’t changed much since I was in school.

But, that pattern of study is not really ideal for good long-term learning.  One of the cornerstones of memory research is the distinction between massed and distributed practice.  Massed practice is when you study all of the information in one burst.  Distributed practice is when you spread your study out over time.  Keeping the total amount of study time constant, massed practice can help for an exam, but it leads to poor long-term recall of the information.  Distributed practice is much better for remembering information over the long-term.

There are several reasons why students might choose to mass their studying right before the exam rather than distributing it over time.  They might just not know that distributed studying is better.  However, they might also just be busy.  Schools often load students up with work, and so it is hard to allocate enough study time in advance of a test, because there is a lot of work to be done.  

An interesting paper by Michael Cohen, Veronica Yan, Vered Halamish, and Robert Bjork in the November, 2013 issue of the Journal of Experimental Psychology: Learning, Memory, and Cognition examined how students allocate study time to items to see if they are sensitive to the benefits of distributing their practice.  

In one study, college students learned word pairs (like truth-justice).  At test, they were going to see the first word and have to produce the second.  Participants first saw all of the pairs on the list one at a time.  They could study them and then were told that the pair would be worth either one point or five points if they remembered it correctly.  Participants were asked to maximize the number of points they got.  After seeing the word pair once and studying it, they were given the option to study it again after a short delay or after a longer one.  When participants chose the short delay, the word pair was shown again after the initial list was seen completely.  Then, a test was given on the items shown after the short delay.  Next, there was a brief distractor period, and then the items with the long delay were shown and a test on those items was given.  

Overall, students tended to prefer to assign the high-value items to the short delay and the low-value items to the long delay.  Despite this preference, they were actually better able to remember the items that they studied with a long delay compared to those with a short delay.  So, people were selecting a method to study that actually made their performance worse.  The researchers replicated this finding in several studies.

In another study, students were able to allocate study time to a hypothetical test they were going to take in the future.  There was a strong tendency to plan for the most study time close to the exam rather than studying more evenly over a long period of time.

Putting all of this together, then, even without any time constraints, students tend to prefer to mass their practice near an exam (cramming) rather than distributing their study time more evenly.  As a result, even when students have the opportunity to learn in a more ideal way, they tend to study in ways that will ultimately lead to more forgetting later.  That means that educators need to do a better job of helping students to develop habits that get them to even out their study time.  It isn’t a matter of studying harder, just studying smarter.

Monday, November 2, 2015

The Emotions Underlying Moral Outrage

Cable TV news is filled with examples of moral outrage.  Hosts of news programs display high levels of anger at some situation going on in the world.  They describe a violation of a deeply-held belief and then their emotion bubbles to the surface.  And, chances are, you have experienced this emotion yourself when a situation crosses one of your moral boundaries. 
But, what kind of an emotion is moral outrage?

This question was explored in a paper in the October, 2013 issue of Psychological Science by Jessica Salerno and Liana Peter-Hagene.  

They explored the influence of anger and disgust on feelings of moral outrage.  The word outrage suggests that anger is a big part of this moral feeling.  And when you are experiencing moral outrage, it certainly feels like intense anger.

These researchers suggest that what separates moral outrage from anger, though, is disgust.  They argue that people need the combination of disgust and anger to get real moral outrage.
In one study, participants viewed testimony and lawyers’ arguments from a murder case.  The testimony included pictures and descriptions of stab wounds from the victim’s throat.  Afterward, participants stated whether they thought the defendant was guilty.  They rated their degree of anger and disgust as well as their sense of moral outrage at the defendant.  

People’s judgments of moral outrage were predicted by a combination of anger and disgust. In particular, anger alone and disgust alone do not create moral outrage.  Instead, it was important to have the combination of the two to experience moral outrage.  The degree of moral outrage then influenced people’s sense of the guilt of the defendant and their confidence in that verdict.  

The researchers also replicated the relationship between anger, disgust and moral outrage using scenarios involving a church group picketing a soldier’s funeral and a description of a sexual assault.  Once again, the combination of anger and disgust led to feelings of moral outrage.  

This research fits with a growing body of work exploring the role of disgust in moral judgments.  Clearly, we experience disgust when there is some situation or food that is dirty.  We extend that disgust to situations that violate our moral beliefs.  So, things that are disgusting have the prospect to engage our moral sense.   When we combine that disgust with anger, then we can slip into the white-hot rage that is common for moral situations.