Wednesday, August 17, 2016

Learning and Sleep in Toddlers

Quite a bit of research has begun to explore influences of sleep on cognitive processes.  In adults, sleep has a huge influence on memory.  Sleep speeds learning of new skills.  It also helps to separate the information being learned from the situation in which it was learned, which can make it easier to use that knowledge in other circumstances.

Young children spend a tremendous amount of time asleep, and so research is also beginning to explore the influence of sleep on things children learn.  An interesting study in the March/April, 2014 issue of Child Development by Denise Werchan and Rebecca Gomez examined how sleep influences toddlers’ ability to learn new words.

When a child learns a new noun, for example, it is important for the child to be able to apply that word to the object (or objects) for which they have seen it used, but also to apply that word to other objects that come from the same category.  For example, a child may sit in the family minivan and hear it called a car.  She may see a neighbor’s sedan and hear that called a car as well.  She might also be given a four-wheeled toy and hear that is a car, too.  To be a successful language-user, this child ultimately has to be able to recognize which other objects should be called a car and which ones should not.

This process requires generalization.  That is, the child has to go from the limited number of instances of the category they have seen to figure out which other objects share the same label.  This process requires some amount of forgetting.  After all, the child will observe many characteristics of these objects like their shape, size, color, and parts.  Some of these characteristics (like shape, and some parts) matter a lot in deciding whether to call something a car, and others (like color) matter less.  So, it is helpful for the child to forget some of what they have seen in order to begin to generalize the new word to other objects.

Werchan and Gomez suggested that sleep might actually interfere with toddlers’ ability to learn new words.  These researchers argued that sleep helps to solidify memories, and so if children associate too much information with a label, they might not learn to generalize it to new objects.

To test this possibility, 30-month-old toddlers were taught labels for three types of novel objects (which were constructed by the researchers).  The labels were words like dax or tiv that are not used as words in English.  During the training, children saw three examples of each object. They were also exposed to several other novel objects that were not labeled, that would be used as distractors later. 

One group of children was tested about an hour before their normal nap time.  They napped, and then came to a psychology lab to be tested four hours after the training.  A second group was tested far from their normal nap time.  They were also tested in the lab four hours after training, but they had not napped.  A third group was trained and then tested immediately.

During the test, children saw four objects:  a new example from one of the categories they learned, an object they saw during training that had not been named, an unfamiliar object, and a familiar object (like a toy duck).  They were told the label and were asked to point to the object.  For example, if they saw the object that had been called a dax during training, they would be asked “Which one’s a dax? Can you point to the one that’s a dax?”

The children who were tested immediately and those who napped got about 40% of the test questions correct.  The children who did not nap got over 80% of the test questions correct.

This study suggests that when toddlers are learning words, their ability to generalize those words to new objects requires them to forget some of what they saw.  More of this forgetting happens when children remain awake than when they sleep.  So, this kind of word learning is enhanced when children stay awake after learning the words.

As the researchers point out, this finding differs from what is usually observed with adults.  Adults often generalize their learning better after sleep.  The difference is that adults are better than toddlers at focusing on the most important information when learning something new.  So, for adults the most important part of generalizing is separating the content of what was learned from the situation in which it was learned.  Sleep helps with that separation.  Toddlers need to forget some of the content of what they learned in order to generalize effectively, and so for them sleep helps them.

Wednesday, August 3, 2016

Guilt and Shame and Crime

When people do something wrong, there are two distinct emotions that they commonly experience:  guilt and shame.  These emotions differ based on what people feel bad about.  When people feel bad about the action they performed, then they experience guilt.  When they feel bad about themselves for having done something bad, then they experience shame.

How do these emotions influence future behavior?

An interesting paper in the March 2014 issue of Psychological Science by June Tangney, Jeffrey Stuewig, and Andres Martinez explored this question with people who had served time in prison for a felony conviction. 

The participants were nearly 500 individuals.  While they were still in prison, they were given an assessment of their tendency to experience guilt and shame following bad behaviors.  They were also given a measure that examined whether they tended to blame circumstances for their actions rather than themselves.  Blaming the circumstance is called externalizing blame, and is often associated with continued bad behavior.  That is, people who do not accept their own responsibility for their actions are less likely to change their behavior in ways that will reduce bad behavior than those who do accept responsibility for their actions.

The participants were also contacted a year after being released from prison.  They were asked to report whether they had been arrested for crimes in that year and whether they had participated in crimes for which they were not arrested.  The researchers also looked up arrest records in the FBI database. 

The researchers then looked at statistical relationships between guilt, shame, the tendency to externalize blame, and the likelihood of continuing to commit crimes.

Guilt and shame had very different influences on future behavior.  Guilt had a negative relationship with future crime.  People with a strong tendency to experience guilt were less likely to commit additional crimes than those with a weak tendency to experience guilt.

Shame had a more complicated relationship to future behavior. 

Shame was positively related to people’s tendency to externalize blame.  So, people who feel bad about themselves after performing a bad action will often try to blame the circumstance rather than themselves in order to help them repair the damage to their self-esteem.  Statistically, the more people externalized blame, they more that they tended to continue to commit crimes after being released from prison.

However, once the researchers accounted for the influence of shame on externalizing blame, shame tended to decrease future bad behaviors.    

What does this mean? 

The problem with shame is that it causes people to feel bad about themselves.  People who deal with shame by externalizing blame will not work to change their behavior.

However, if people experience shame without externalizing blame, then they will act more like people who feel guilty.  Both shame and guilt are negative emotions, and so people will work to find ways to avoid feeling bad.  One good way to keep from experiencing guilt or shame is to change behavior. 

This research also helps to demonstrate why the way we categorize the world is so important.  People experience shame when they use bad actions they have performed to categorize themselves as bad people.  People experience guilt when they think of themselves as people who happened to perform a bad action.  It feels easier to change your behavior when you are focused on changing an action than when you feel like you have to change who you are at your core. 

Tuesday, July 19, 2016

Having the Option to Do Nothing Increases Commitment

We often assume that giving people the chance to choose what they are going to do will increase their motivation to do it.  One reason why many colleges give their students so much autonomy is with the belief that if students have selected the classes they take they will put more effort into those classes than if the classes were assigned to them. 

Of course, when you are actually engaged in a task (like taking a class), the alternatives you have in front of you are to work on the task or to do something else entirely and give up on the task.  So, perhaps it would be helpful to get people to explicitly decide that they prefer the task to doing nothing. 

This possibility was explored in a paper in the March, 2014 issue of Psychological Science by Rom Schrift and Jeffry Parker. 

In one study, they gave participants a choice between one of two word searchers in which they had to find as many words as possible in a grid.  They would be paid based on the number of items they found.  One search involved finding actors names, while the other involved finding capitol cities.  A second group got the same two choices as well as the option not to participate in the task.  Nobody chose not to participate.  A third group was given a choice of three puzzles, one of which had unfamiliar terms (famous ballet dancers) that no participant selected.  This last condition was there to control for the possibility that having three options rather than two mattered.

The participants given a choice between two or three puzzles spent about 5 minutes working on the puzzle they selected.  Those who were given the option not to participate spent about 7 minutes working on their selected puzzle.  So, explicitly choosing to do something rather than not to do it greatly increased the amount of time people spent on the task. 

A second study demonstrated that the option to participate has to be given when people are choosing the task to perform.  In this study, some participants were first told they could opt in to doing a second study as part of an experiment.  After opting in (which everyone did), they selected one of two tasks.  A second group was given a choice between the two tasks or the option not to participate.  Everyone in this group also agreed to participate.  In this study, the two options (a perception task and a cognition task) were vague enough that all participants actually performed the same task.  Participants who had to choose to do a task rather than not to do one spent more time on the task and performed better than those who first opted in and then selected a task.

Finally, a third study found that choosing to perform a task rather than doing nothing only influenced the particular task selected.  In this study, some people chose one of two tasks to perform, while a second group chose a task, but had the option to do nothing (which nobody picked).  Before doing the task they selected, they were given a second task in which they had to find as many differences between a pair of pictures as possible.  People spent the same amount of time on this extraneous task regardless of the choice condition they were in.  But, then, participants given the option to do nothing spent more time on the experimental task than those just given a choice between two experimental tasks.

Putting all of this together, there seems to be real value in getting people to commit to doing a particular task by having them choose explicitly to do that task rather than doing nothing.  This advantage reflects that stopping a task is essentially choosing to do nothing rather than doing the task.  Of course, future research must explore whether the influence of opting against doing nothing has a long-term influence on motivation.  The experimental tasks in this paper are all short.  It is not clear whether opting to take classes rather than not to take classes would affect a student’s motivation for an entire semester.

Wednesday, June 29, 2016

Creating Personalized Practice for Students

For a few decades now, educators have suggested that computers would vastly improve our ability to teach students.  The assumption has been that with computers we would be able to transport students to places they could not go on their own, allow them to communicate with people around the globe, and get more personalized instruction.

So far, the influence of computers in education has been mixed.  Computers clearly allow access to a much larger library of materials than students would were able to get before the internet.  In addition, students can view interesting videos that bring more content than the filmstrips and videos that were the norm in the past. 

However, computers have had a downside as well.  The internet provides a lot of distraction that leads students to try to multitask in ways that hamper learning.  Video lectures (like MOOCs) have not yet lived up to the hype.  It is just hard to watch a lecture on a screen.   And there have been few successful methods for personalizing instruction to individual student needs.

This issue of personalized practice was explored in a paper by Robert Lindsey, Jeffery Shroyer, Harold Pashler, and Michael Mozer in the March, 2014 issue of Psychological Science. 

They compared three methods for helping eighth-grade students to learn Spanish vocabulary.  For each of these methods, all students studied for the same amount of time. 

One group of students just practiced the most recent lesson each week for 10 weeks.  This process is similar to what many students do now when their weekly quizzes focus on the most recent material.  A second group got a generic kind of practice that spaced practice out over weeks in which they were given the chance to study both material from the current lesson and from the previous lesson. 

A third group used a more complex technique to guess what material each student was most likely to be just about to forget.  This technique used a student’s performance each week to estimate their overall ability to remember vocabulary, the difficulty of particular items (judged by how well students in general were able to learn those items) and how often they had seen those items previously.  Using this technique, students spent most of their time each week on the new items from the current lesson, but then received a smattering of older items to help them with older information that they would be likely to forget.

Students got a test at the end of the semester and another test after a four-week break as they started the next semester.  On both tests, students given the personalized training regimen did much better than those who either studied just the words from the current week or those who studied the words from the previous week and those from the current week.  The biggest benefit for the personalized training came for items that were learned early in the semester.  Students given this training were much less likely to forget those items than those given the other two techniques.

This finding suggests that when students are learning information that requires a lot of practice, computers may be used to individualize practice for the needs of particular students.  Of course, computers are just enhancing a piece of the learning here.  Picking up a new language requires learning vocabulary, but it also requires learning to actually communicate.  This technique helps with memorization, but not with the use of the new language.

One concern that I have with this technique, though, is that students need to learn material, but they also need to learn to study effectively.  That is, students need to learn that the reason that they succeed with this new technique is because it finds difficult items from the past that they are just about to forget and gets them to study those items.  These students will not always have a computer in front of them helping them to figure out what material to study.  So, they need to learn to apply some of these strategies on their own in order to maximize their ability to learn in the future.   

Wednesday, June 22, 2016

Studying Learning Using Video Games

A subtheme in this blog has been the influence of video game play on people’s behavior.  There is an ongoing debate about both the potential negative impact of playing games (such as increases in aggression or lower grades) as well as positive influences (like an increase in prosocial behavior after playing games with positive messages and an increase in speed of decision making).

Video games themselves can also be a great testing ground for theories of learning.  That was the approach taken in a fascinating paper in the February, 2014 issue of Psychological Science by Tom Stafford and Michael Dewar.

They were interested in testing a fascinating theory about learning new skills.  The idea is that any time you are learning something new, there is a tradeoff between exploiting past knowledge and exploring new strategies.  The proposal was that people who succeed best in learning new skills start by exploring a range of strategies.  This exploration may cause them to do well when they hit on a potentially good strategy and to do poorly when they try something that does not work well. Then, when people find a good strategy, they should exploit it and keep improving their skill.  Those who settle on a strategy too quickly (and so they start exploiting early) may end up picking one that is far from optimal, and so they will do more poorly in the long run.

They worked with a game designer to create an on-line game called Axon.  The game involves making simple selections of targets on a screen.  Some of the dots are colored, and the colored dots have different influences.  Some colors are better to hit than others.  So, there is some strategy, but the strategies are not complex and are mostly focused on which color dots should be selected. 

During the data collection period, the game was played over 3.5 million times by over 850,000 players.  Most of the analyses were done on the 45,672 individuals who played the game 10 or more times.

Before addressing the key experimental question, it was important for the researchers to make sure that the data gave sensible results.  So, they started by verifying that two classic phenomena from learning studies occurred in this data set.  The first was the observation that performance improves with practice.  Looking at those people who played at least 10 games, it was clear that the more games people played, the better they got. 

Second, it is well known that when people space their practice out over time, their performance is better than when it is concentrated together.  There are several reasons for the improvement for practice that is spaced out over time.  One is that spaced practice allows information being learned to become associated with many different contexts. The second is that sleep improves skilled performance, and the more times people play and the more time that elapses between attempts, the more likely that people will sleep between attempts at the game.

Consistent with the prior work on this topic, people who concentrated their game play together did worse at the game than those who spread their play out over time.

Because the game yields sensible data, the researchers could look at the more complex question relating early strategies to later performance.  The researchers looked at the degree of variability in the scores over the first five games people played.  The more variable the scores, the more strategies people were likely to have tried early on.  They looked at how this variability was related to the high score people achieved on the next five games they played. 

The more variable people’s scores in the first 5 games, the higher their best score tended to be in the next five games.  That is, exploring a range of initial strategies allowed participants to do better than selecting a single strategy early on and sticking with it.  

There are two interesting things about this project.

First, it is a great example of using the internet to look at learning in a large number of people.  Most research studies done at universities involve a small number of participants who perform a small number of trials on a task.  This game is still fairly simple, but it allowed a large number of people to play it.

Second, these findings suggest that it is valuable to try a number of different strategies in any task before settling on one.  People who did this naturally in the game were more successful than those who did not.  An interesting follow up study would explore whether people who are instructed to try different strategies also do better than those who are instructed to select a strategy and stick with it.  That would disentangle whether these results reflect that people who are better at video games are those who also try more strategies, or whether anyone can improve by trying more strategies. 

Tuesday, May 24, 2016

Kids Want to Learn About Kinds, Not Individuals

By the time you are an adult, you know a lot about the world.  You know that dogs bark, that computers allow you to communicate with people around the planet, that airplanes fly you from city to city, and that water boils at 100 degrees Celsius.  You also know a lot about individuals you have met.  You know your mother’s maiden name (which is handy when you need to open a bank account).  You know your best friend’s favorite color, the toy your aunt’s dog likes to play with, and exact way you need to unlatch the gate at your grandparents’ house. 

Your knowledge about individuals is useful for helping you to interact with specific situations in the world.  Knowing your best friend’s favorite color can help you buy a gift for her birthday.  Your knowledge about kinds of things (like dogs in general) can help you to predict what you should expect when you encounter a new dog.  Ultimately, you need to learn information about kinds of things in the world as well as information about the specific individuals you encounter.

An interesting paper by Andrei Cimpian and JoAnn Park in the February, 2014 issue of the Journal of Experimental Psychology: General examined what 4- and 5-year-old kids do when they are given a choice to learn about a particular individual or a kind in general.  

In one experiment, children sat with an experimenter who brought pictures of several unfamiliar animals (like a pangolin and a tarsier).  For half the children, the experimenter said that she was an expert and knew a lot about these animals.  For the other half of the children, the experimenter said she did not know much about the animals, but could guess some facts about them.

The experimenter showed a picture of an animal and said that she could tell the child a fact about that particular animal or about that kind of animal in general.  Children would let the experimenter know what kind of fact they wanted, and they would be given a fact.  Children were able to learn 3 facts for each picture and there were 4 pictures for a total of 12 trials.

When the experimenter said she was just guessing, children had no preference for getting facts about individuals or kinds.  This result makes sense, because the facts the child is getting are equally useless.  When the experimenter said she knew a lot about the animals, though, the children wanted information about the kind of animal much more often (64% of the time) than they wanted information about the individual.

One possibility is that children just want information that applies to more individuals, and that is why they choose to get facts about the kind.  In a second study, some children were given the chance to get a fact about the animal pictured or about several other specific animals that were not in the picture.  In this condition, children had no preference for getting a fact about one animal or a fact about several.  

Finally, a third study repeated the first experiment with familiar animals (like sharks, ants, and crickets).  Once again, children had no particular preference for facts about individuals or kinds when the experimenter said she didn’t know anything about the animals, but preferred to get facts about the kind in general when the experimenter said she was an expert.

This result suggests that when young children are around people with expertise, they want to learn about categories of objects.  This bias helps them to learn facts that will help them to deal with new things that they encounter.  This finding also argues against another way that children could learn about the world.  Children could learn lots of facts about individuals and then try to generalize those facts to apply to all members of the kind.  Instead, children prefer to learn about facts that apply to the kind. 

Wednesday, April 27, 2016

People Differ in Their Ability to Suppress Memories

Your ability to recall a word or event involves mechanisms that enhance the item you want to remember and suppress competitors.  It is like a bunch of 6-year-olds trying to be picked for the kickball team.  The kids who jump the highest and shove the other kids hardest are the ones who are selected.

Psychologists use the word inhibition to refer to the suppression of items in memory.  The inhibitory mechanisms in the brain involve circuits in the frontal lobes.  

A fascinating observation over the past decade is that these inhibitory mechanisms in the brain can cause subtle variability in people’s heart rate through the vagus nerve.  If you measure someone’s resting heart rate and measure the amount of variability in the time between beats, that variation may serve as a marker of the strength of people’s ability to inhibit information in memory.

An interesting paper by Brandon Gillie, Michael Vasey, and Julian Thayer in the February, 2014 issue of Psychological Science explored this possibility.  

They used a memory test called the Think/No Think procedure first developed by Michael Anderson and his colleagues.  In this procedure, people learn a list of associations between words.  The list might include items like “tape-radio.” 

After practicing these associations 3 times, the Think/No Think procedure begins.  The first word of a pair (tape) is presented in green or red (or is not presented at all).  If it is presented in green, then people are instructed to think about the associated word for 4 seconds.  If it is presented in red, then people are instructed to avoid thinking about the associated word for those 4 seconds.  This procedure is repeated 16 times, so that people get a lot of practice either thinking about the association or not thinking about it.  

There are two tests of recall.  People see the first word of the pair and are asked to recall the second.  In a second test, they see the first word of the pair and the first letter of the second word and are asked to recall the second word. 

Finally, all participants had their heart rate collected using an electrocardiogram (ECG).  The ECG output was analyzed to determine the variability from beat-to-beat.

The standard finding with this procedure (which is also obtained in this study) is that (on average) people recall about 10% more of the associations when they see them in the Think condition than in the No Think condition.   

The group of participants was split into one group with relatively high variability in heart rate and a second group with relatively low variability in heart rate. 

Having low heart rate variability is associated with having low inhibitory control in memory.  That group showed very little difference between the Think and No Think conditions of the study.  They remembered the associated words equally well regardless of whether they were instructed to think about them or not to think about them.

Having high heart rate variability is associated with high inhibitory control.  That group showed a big difference between the Think and No Think conditions.  They remembered many more words when they were encouraged to think about them than when they were encouraged not to think about them.

The ability to inhibit unwanted items in memory is valuable.  Research suggests that this ability degrades with age, which is one reason why older adults often have trouble with memory.  So, having a physiological measurement that relates to this degree of inhibitory control is useful.
As valuable as the ability to inhibit information can be, it is important to recognize that the No Think condition does not eliminate people’s ability to recall the associated words.  Creativity requires being able to think about information that does not seem obviously related to the current situation.  Juxtaposing different information sources is a great way to look for a novel solution to a problem.  As a result, we want to have good inhibitory mechanisms, but not ones that work too well.