Posts Tagged ‘Alexandra Michel’

The Happiness U-Curve

March 16, 2017

This post is based on a section with the same subtitle in “The Cognitive Upside of Aging” an article by Alexandra Michel in the February 2017 “Observer”, a publication of the Association of Psychological Science (APS).

Despite all the negative components of aging, researchers consistently find a happiness paradox:  As the body declines, happiness tends to increase.  Across the lifespan this “Positivity effect” follows a U-shaped pattern:  happiness starts out high in late adolescence, bottoms out in middle age, and reaches a second zenith in old age.

A 2011 Gallup analysis of 500,000 phone interviews found that “a septuagenarian is far more likely than someone in their 30s to have high emotional health.  This happiness advantage held true even after controlling for demographic factors, including gender, race, education, marital status, employment, and regional location.

This happiness U-shape appears across the world.  Economists Andrew Oswald and David G. Blanchfower documented this pattern in more than 500,000 people living in more than 70 different countries.  Their analysis concluded that from Azerbaijan to Zimbabwe, people around the world tend to be happiest in their old age regardless of their nationality.

Oswald says, “Only in their 50s do most people emerge from the low period.  But encouragingly, by the time you are 70, if you are still physically fit then on average you are as happy and mentally healthy as a 20 year old.  Perhaps realizing that such feelings are completely normal in midlife might even help individuals survive this phase better.”

This universality of happiness U-curve implies the aging may play a positive role in the brain.  A team of Australian researchers led by Leanne Williams, who is now at the Stanford University School of Medicine, argues that a combination of neurological changes and life experiences account for this phenomenon.  Using functional magnetic resonance imaging (fMRI) to monitor emotional processing as people of various ages viewed photographs of different facial expressions, the researchers found that older people were more emotionally stable and less reactive to negative emotional stimuli than younger people.

Contrary to the ubiquitous negative stereotypes of declining memory and cognitive integrity, Williams and colleagues found emotional well-being may increase with normal aging.  Their study included 242 individuals (122 males and 120 females) divided up into four major age categories:  12-19 years, 20-29 years, 30-49 years, and 50-79 years.  Participants were assessed in the scanner for the neural activation evoked by emotions of threat and happiness depicted in facial expressions.  After being shown a photograph of a face, participants had to select the best option for identifying the emotion being displayed in the photograph.  They also rated on a 1-to-5 scale, the intensity of the emotion being displayed.
Rather than showing an inevitable decline across all functions, the images displayed a linear increase in emotional stability with age, meaning that people in their 70s ultimately experience better emotional well-being than most people in their 20s.

The fMRI results suggest that as we age, the way our brains process emotional stimuli  changes in ways that favor emotional stability.  The brain scans indicated that the medial prefrontal cortex (mPFC), which is a brain area involved in the governance of emotional functions, processed stimuli differently across the lifespan, contributing to better emotional stability for older adults.  As we age, the mPFC areas become increasingly active while processing negative emotions compared with positive ones, suggesting that older people were comparatively better at controlling negative emotions.

This article ends as follows: “Ultimately Williams and colleagues argue that as we age this combination of neural processing, as well as an accumulation of life experience, provides older adults with the neural tools to take life in stride—a capability their younger counterparts will just have to wait for.”


Finding Focus

March 15, 2017

This post is based on a section with the same subtitle in “The Cognitive Upside of Aging” is an article by Alexandra Michel in the February 2017 Observer, and publication of the Association for Psychological Science (APS).  This study  used data collected from and was published in “Psychological Science.”  It found another unexpected boom for aging brains:  Sustained attention tends to improve over time, peaking in the mid-40s.

This study was led by Francesca C. Fortenbaugh, Joseph DeGutis, and Michael S. Esterman of the Boston Attention and Learning Laboratory at the VA Boston Healthcare System.  This study tested sustained attention across 10,430 adults using a specialized task for identifying individual differences in people’s ability to focus on a single task over 4 minutes.  DeGutis said in a statement, “While younger adults may excel in the speed and flexibility of information processing, adults approaching their middle-years may have the greatest capacity to remain focused.  One current hypothesis  is that compared to younger adults, adults in their mid-years mind-wander less, leading to better sustained attention performance.  This sample was larger than all previous efforts to model changes in sustained-attention performance during development, aging, or across the life span combined, which allows us to more precisely model transition periods in performance across the life span using segmented linear regression”

Sustained attention underlies several important cognitive processes, including learning, perception, and memory.  Lapses in attention can lead to serious problems ranging from difficulty at work to an increased risk of car accidents.  Measuring attention across individuals is itself a challenge; attention fluctuates, sometimes dramatically, from moment to moment.

The researchers used a new tool they developed:  the gradual-onset continuos performance task (gradCPT).  Participants were shown serious of grayscale photographs go 10 city scenes and 10 mountain scenes.  One photograph gradually transitioned into the next every 800 milliseconds, so that as one image faded, a new image steadily took its place.

There were 5,027 male and 5,403 female participants between  10 and 70 years old who completed the gradCPT on between March and September of 2014.  The participants were told to press the space bar whenever they saw a city scene, but to withhold a response when the image was a mountain scene.  Here the goal was to create a task that required frequent responses from participants while having a relatively low cognitive demand.  Identifying the differences between the two scenes was easy, but carefully attending to the transitions repeatedly became challenging over time.

By analyzing mean reaction time, reaction time variability, hits, misses, discrimination ability, and criterion (a measure of strategy or willingness to respond in the case of uncertainty), the researchers were able to tease apart the changes in unsustained attention across the lifespan.  From the ages 10 through 16, gains in both reaction times and discrimination ability were extremely large.  After age 16, gains in these skills were much smaller until they peaked around age 43.

A factor analysis of the results suggests than people also begin to use different cognitive strategies as they age.  Younger individuals demonstrated faster reaction times (due to either super information-processing speed or more liberal response strategy), whereas older individuals showed a slower, more cautious strategy and evidence they made more adjustments after a mistake.

The Cognitive Upside of Aging

March 14, 2017

“The Cognitive Upside of Aging” is an article by Alexandra Michel in the February 2017 “Observer”, a publication of the Association for Psychological Science (APS).  This article corrects some major misconceptions about memory and aging.  This realization is important as the expectation is that “the next ten years will witness an increase of about 236 million people aged 65 or older throughout the world.”

A 2014 survey on perceptions of brain health and aging conducted by the AARP found that people believed that the brain peaks at age 29 before beginning to deteriorate by age 53.  Now these are opinions regarding brain health and aging.  Actual research on this topic reveals how woefully in error these conceptions are.

Joshua K. Hartshone of Boston College, and Laura Germine of the Harvard Medical School reanalyzed an old set of scores from the Wechsler IQ and memory tests taken by a geographically diverse group of adults in the 1990s.  Scores from 2,450 test-takers were divided into 13 age categories representing people between the ages of 16 and 89.  The researchers then charted peaks in a variety of cognitive skills, ranging from memory to vocabulary, from adolescence through old age.

There was no single apex in overall cognitive skill.  Instead, there was a huge variation in cognitive capabilities across the lifespan.  The cognitive peaks were all over the place.  Hartshone said that this was the “smoking gun” that it’s not all downhill for the aging brain.

Although these data were important, the pool of participants was too small to make any solid conclusions.  Most psychological research is done with people in their late teens and early 20s.  Getting people in their 50s, 60s, and 70s into the lab is a major obstacle.

Hartshone and Germine were quite creative in addressing this obstacle.  The decided to use viral Internet quizzes.  Along with Ken Nakayama of Harvard University Germine founded   This website hosts a variety of short cognitive tests that users can complete within minutes.  Since the site’s foundation in 2008, data has been collected from more than 1.7 million volunteers across the country.  Hartshone has founded a website called as a “Web-based laboratory” for studying language.

Both Hartshone and Germine thought it important for the tests on the websites to be short and engaging  to ensure that participants enjoyed taking each one so much that they would be interested in taking a few more or even forwarding them to friends.  They wanted to make taking a cognitive battery just as easy and fun as taking one of the not-so-scientific personality tests people like to take on social media sites.  More than 3 million people have taken quizzes on the two websites.

In this new set of studies Hartshone and Germine used and to collect large samples of data across five specific cognitive tasks.  Three of these tasks, digit symbol coding, verbal working memory, and vocabulary, overlapped with the tasks from the Wechsler exam used in the previous study.  The researchers also included a widely used test of emotional perception, which was not included in the original Wechsler tests.

These test data collected from online participants shows a very clear picture of cognitive peaks across the lifespan, one that largely matched the same pattern of results from the decades-old Wechsler tests.  Information processing speed crested early in life, around the age of 18 or 19.  Short-term memory improved until age 25 before beginning to decline around 35.

However, many cognitive proficiencies, vocabulary, math, general knowledge, and verbal comprehension did not peak until much later in life.  These results make sense because people should continue to learn new things and gather new experiences as they age.  These skills are usually regarded as belonging to crystalized intelligence.  Vocabulary skills had no single high point and continued to improve well into participants’ late 60s and early 70s.  The Wechsler data show vocabulary skills topping out mostly in the 40s.  To reconcile these results Germine and Hartshone inconcluded the General Social Survey, which has been testing people’s vocabularies for decades.  These data confirmed that there really has been a steady shift in vocabulary performance  over the last few decades.

Germine and Hartshone wrote, “With the increase in the proportion of adults engaged in cognitively demanding careers, it may be that ages of peak performance are later in the more recent Internet sample, particularly for vocabulary.  This could be related to the Flynn effect that IQ has increased steadily in modern times, possibly because of increasing amounts of time devoted to mental activity.”

The Flynn Effect refers to the need to recalibrate the IQ test so that they would have a mean of 100.  For years, Flynn argued that this must be some sort of artifact.  See the healthy memory blog post “More on Flynn and the Flynn Effect” to learn how Flynn decided that this increase was real and not an artifact.  Moreover, he attributed it not just to the amount, but also to the types of cognitive processing people were doing.

Emotional skill also improved with age.  To test this ability, researchers asked participants to identify the mood of a person based only on a photograph of the individual’s eyes.  A menu provided a selection of potential options such as  fearful, tentative, or playful for each photograph.  Adults in their 40s and 50s consistently outperformed much younger adults.  This ability had a much longer plateau than any of the other cognitive skills that were tested.  Germaine and Hartshone wrote “The peak in emotion-recognition ability was also much broader than any of the other tasks, which reflects a long period of relative stability in performance between the ages of 40 and 60 years.”

The researchers recruited another large set of more than 18,000 online participants between the ages of 10 and 73 to confirm their visual and verbal working-memory findings.  The replication found the same pattern of cognitive peaks as the other experiments.

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