Experimental Psychology – Dr Martin Fracker

Does Your Mind Wander When You Should Be Paying Attention? Join the Club!

Imagine you are driving to a meeting. It’s a long drive and you don’t want to miss your exit off the freeway. But while you are driving, your mind begins to wander off to other things, like the argument you had with your spouse yesterday, or the Hawaiian vacation you are planning for next winter. And then after a while you notice that you past your exit over a ten minutes ago! Does this mean there is something wrong with you? Are you starting to lose your mind? The answer is no. As Zanesco and colleagues confirmed in a meta-analysis of 68 studies of mind wandering during task performance, it just means you are like everyone else!

How Do Our Cognitive Abilities Change As We Age?

In July 2024, President Joe Biden withdrew from his campaign for reelection to the US Presidency largely due to concerns over his apparent decline in cognitive abilities. But what do we actually know about how our cognitive abilities decline as we age? Breit and colleagues decided to examine the stability of eleven major cognitive abilities over the lifespan from preschool age to late adulthood (80 and older). They analyzed the results of 205 studies testing over 87 thousand individuals at various points in their lives, using a test-retest procedure. As we might expect, they found that cognitive abilities grow rapidly during the first 20 years of life and then become remarkably stable for the remainder of the lifespan. Nevertheless, significant individual differences in cognitive stability appeared in later adulthood with some older individuals (55 to 90 years of age) showing greater declines in cognitive ability than others in the same age group, with the biggest individual differences in cognitive stability appearing around age 70.

Fluid versus Crystallized Cognitive Abilities

One particularly important finding was that reasoning abilities that require cognitive effort (fluid reasoning) were more likely than knowledge-based abilities (crystallized intelligence) to decline as people aged. The authors explained this somewhat counter-intuitive result as follows:

This theory proposes that during cognitive development, fluid (or effortful processing–based) abilities are invested in the acquisition of crystallized (or knowledge-based) abilities. As the result of years of cumulative investment, these crystallized abilities are acquired and automated, such that they are better maintained even as currently available processing power wanes with aging…or varies from day to day. [p.424]

President Joe Biden, prior to his decision to end his reelection campaign, similarly argued that while he was indeed aging, he had accumulated vast wisdom and political know-how; that is, crystallized intelligence. He was probably right. Voters’ concern of course was that a President also needs to be able to reason through new problems that inevitably arise from time-to-time, if not daily.

How Much More Is $100 Today Worth To You Than $200 Next Year? It Depends!

Talk to a young adult who is planning to skip college so they can get a job and start working today. Try to explain to them that they could eventually make a lot more money if they graduated from college in four years with a marketable degree. Quite often they will be unmoved because $100 today is simply worth more to them than $400 four years from now. Psychologists call this relative judgment of worth “delay discounting.”

Many of us think that delay discounting affects young people more than older adults, perhaps because greater maturity and wisdom enables older adults to more clearly see the benefits of waiting until our earning power has increased. There are actually several different theories to explain why delay discounting lessens as we age, but some of those theories predict that delay discounting isn’t linear with age but rather “U-shaped” where delay discounting decreases with age up to a point and then increases again as we continue to grow older. Such a U-shaped discounting effect may make sense to us if we consider that a delay of ten years, say, may loom larger to a seventy year old than to a thirty year old.

Lu and colleagues decided to test the predictions of various theories of delay discounting by performing a meta-analysis of 105 relevant research studies. They found that those theories that predict a U-shaped discounting effect were indeed correct, but that the reasons for the U-shape are more complicated than just how many years one has left.

Do Emotions Make It Harder to Think and Act Logically?

In the classic television show “Star Trek”, the Vulcan character Mr. Spock was able to think and act more logically than his human shipmates because he did not experience emotions. The implication of course is that human emotions somehow interfere with thinking logically. But is this true?

There have been many experiments designed to find out whether emotions interfere with something called “cognitive control”, which is the ability to ignore irrelevant information that would otherwise interfere with performing an important cognitive task. Results from these experiments have been confusing, so Zhang and colleagues decided to see if a meta-analysis of 71 of these studies would clear things up. Their results show that the kinds of emotions that can be studied in a laboratory setting don’t interfere much with cognitive control and may, under the right circumstances, even help. So perhaps Vulcans don’t have such a big advantage over us emotional humans after all.

It’s Right in Front of You!

You open the refrigerator looking for the ketchup but you don’t see it. You ask your spouse “Where did you put the ketchup?” They look and say “It’s right there in front of you!” And then, surprised, suddenly you see it. You have just experienced inattentional blindness (IB).

Inattentional Blindness happens to most of us everyday. It may manifest as “refrigerator blindness” or “pantry blindness” or, more seriously, “pedestrian blindness” while driving. But what causes IB? There are two main theories: Attention Set and Load Theory (Attention Capacity). Attention Set predicts IB will occur when a person is looking for one thing and doesn’t see something else, which doesn’t seem to fit the “refrigerator blindness” example but could explain “pedestrian blindness”. Load Theory, on the other hand, predicts IB will occur when attention capacity is somehow overloaded, which could explain both refrigerator and pedestrian blindness. Hutchinson and colleagues set out to discover whether data from 81 different studies testing one or both of the theories could help determine which theory did a better job overall of explaining IB. Their conclusion: both theories do a pretty good job of explaining Inattentional Blindness but do so under different circumstances.

Paying Full Attention is Crucial When Learning New Information

Some people claim they can learn new information while their attention is divided. Think of the college student who is watching television while studying for an exam. Such claims appear not to be true. Murphy and colleagues evaluated the ability of participants to learn new information while dividing their attention between studying a list of words and performing a secondary auditory detection task. They found that, compared to participants who could devote their full attention to studying the list of words, participants with divided attention performed less well in recalling the list of words later. Interestingly, the effect of divided attention while recalling the list of words was less severe. Does this mean that while students should not watch television while studying, it would be okay for them to listen to a baseball game while taking their final exam? Perhaps, but I wouldn’t recommend it!

Eye Movements Reveal How We Remember Visualspatial Information

When we have to learn something new, that new information has to get through what you might think of as “gates”: first it has to be perceived, then pass into working (or short-term) memory, and then finally into long-term memory. Moving information from working to long-term memory usually requires rehearsal, like repeating someone’s name to yourself over and over again until you have it memorized. This experiment by Sahan and colleagues shows that the same is true of visual information and answers the question: how exactly do we rehearse visual information? Their answer: we rehearse visual information with help from our eyes!

Limited Attention Capacity Limits Situation Awareness

When people are in engaged highly dynamic environments where lots of things are happening all at once, they may not be able to pay adequate attention to everything simultaneously. We would expect them to allocate their attention to those things they judge to be most important. This insight suggests that limited attentional capacity should limit people’s situation awareness.

In this experiment, I placed participants in a simulated combat environment and tried to manipulate their attentional priorities. In order to assess the impact of these manipulations on situation awareness, I employed a memory probe procedure in which we would occasionally interrupt the simulation and query the participants on details of the tactical situation.

Why Is It Hard To Do Two Things At Once?

Divided attention can be deadly, as we know from warnings not to text or talk while driving. But why exactly is it sometimes difficult to divide our attention between two tasks like driving and talking? Back in the 1980’s, psychologists were testing and debating several competing theories to explain the costs of doing two things at once. Chris Wickens and I wondered if perhaps some of these different theories were not really competing after all but were rather complementary, each tapping into different ways that simultaneous tasks might interfere with each other. Could we design an experiment that would help us find out?

We realized that a dual-axis tracking task could provide us with the opportunity to test the distinctive contributions of different sources of difficulty in divided attention. Dual-axis tracking, after all, could be configured in different ways such that, on one hand, subjects were literally performing two separate one-dimensional tracking tasks simultaneously or, on the other hand, performing a single tracking task in two dimensions. We knew that control system engineers had devised mathematically sophisticated ways of measuring tracking performance that might reveal more precisely what the sources of interference in dual-axis tracking could be. So we designed an experiment in which we measured how well participants performed dual-axis tracking tasks under a variety of different configurations, and then we looked at what our results meant for the different competing or complementary theories in play.