Posts Tagged ‘Executive functions’

Speaking Two Languages May Help the Aging Brain

December 13, 2018

The title of this post is identical to the title of an article by Ramin Skibba in the Health and Science Section of the 11Dec 2018 issue of the Washington Post. The article notes that the first main advantage involves what is referred to as executive function. This includes skills that allow us to control, direct and manage our attention, as well as our ability to plan. It also helps us to ignore irrelevant information and focus on what’s important. Having two languages and the languages being activated automatically and subconsciously, the bilingual person is constantly managing the interference of the languages so that the wrong word in the wrong language at the wrong time isn’t said. These same brain areas are also used when trying to complete a task while there are distractions. This task might have nothing to do with language; it could be trying to listen to something in a noisy environment or doing some visual task. The muscle memory developed from using two languages can apply to different skills.

Executive functions are the most complex brain functions that separate us from apes and other animals. They’re often observed in parts of the brain that are the newest in evolutionary terms: the prefrontal cortex, which is responsible for advanced processing; the bilateral supra marginal gyro, which plays a role in linking words and meanings; and the anterior cingulate. Studies show that the bilingual experience alters the structure of these areas.

There are increases in gray matter volume. Gray matter refers to how many cell bodies and dendrites there are. Bilingual experience makes gray matter denser, so there are more cells. This is an indication of a healthier brain. Bilingualism also affects white matter, a fatty substance that covers axons, which are the main projections coming out from neurons to connect them to other neurons. White matter allows messages to travel fast and efficiently across networks of nerves and to the brain. Bilingualism promotes the integrity of white matter as we age. It gives us more neurons to use, and it strengthens or maintains the connections between them so that communication can happen optimally.

When the brains of bilingual individuals who have suffered neurodegeneration are examined, their brains look damaged. From their brain scans one might think these people should be more forgetful, or they should’t be coping as well as they are. But this is not the case. A bilingual brain can compensate for brain deterioration by using alternative brain networks and connections when original pathways have been destroyed. Researchers call this theory “cognitive compensation” and conclude that it occurs because bilingualism promotes the health of both gray and white matter.

A continuing theme of the healthy memory blog is that memory health is dependent on staying cognitively active. We need to be continually learning throughout our lifetimes. This provides not only for memory health, but also for a more fulfilling life. As was described in the preceding paragraph, the brain can compensate for brain deterioration by using alternative brain networks and connections when original pathways have been destroyed. As has been described in many previous healthy memory blog posts that autopsies have been done of people whose brains were full of the neurofibrillary tangles and amyloid plaque, which are the defining features for a diagnosis of Alzheimer’s, but who never had any of the behavioral or cognitive symptoms of the disease.

Interference

September 11, 2017

Interference is the title of a chapter in “The Distracted Mind” by Drs. Adam Gazzaley and Larry Rosen. Frequently we feel challenged when trying to fulfill even fairly simple goals. This is the result of interference caused by distractions from irrelevant information and interruptions by our attempts to simultaneously pursue multiple goals. Our sensitivity to interference was not born out of modern technology. Rather, it is a fundamental vulnerability of our brain.

Interference is a term used to describe something that hinders, impedes or derails another process. Goal interference occurs when we reach a decision to accomplish a specific goal (look for something to eat, complete a work assignment, engage in a conversation, drive a car) and something takes place to hinder the successful completion of that goal. This interference can either be generated internally, presenting thoughts within our minds, or generated externally, by sensory stimuli such as restaurant chat, beeps, vibrations or flashing displays. This goal interference, regardless of whether generated internally or externally (frequently both) occurs in two distinct varieties—distractions and interruptions—depending upon how we manage the interference.

Distractions are goal-irrelevant information that we either encounter in our external surroundings or generate internally within our own minds. When it comes to distractions, our intention is to ignore them. For example, we are trying to enjoy a television program, but we start worrying about a meeting tomorrow. This is an internal distraction commonly referred to as mind wandering. Mind wandering is particularly troublesome when we are trying to study. These are internal distractions.
But suppose while we’re trying to watch a television program, but are disturbed by something happening elsewhere in the house. This is an example of an external distraction.

Interruptions are the other major source of goal interference. Interruptions can come from external sources from people or environmental events. But interruptions happen when we make a decision to concurrently engage in more than one task at the same time, even if we attempt to switch rapidly between them. These latter interruptions are commonly referred to as multitasking, although research has shown that we cannot multitask. Rather we can switch between or among tasks, but switching itself entails cognitive costs.

Our brains are extremely sensitive to interference at many levels. The reason why goal interference is so prominent in our lives is the inherent complexity of our goals and the limitations we have in fulfilling them. The authors state that our ability to establish high-level goals is arguably the pinnacle of human brain evolution. The authors continue, “Complex, interwoven, time-delayed and often shared goals are what allow us humans to exert an unprecedented influence over how we interact with the world around us, navigating its multifaceted environments based on our decisions rather reflexive responses to our surroundings. Our impressive goal-setting abilities have permitted the remarkable development of our cultures, communities, and societies and have enabled us to create complex human constructs such as art, language, music, and technology. The sheer magnitude of our impressive goal setting-abilities has resulted in the conditions necessary for goal interference to exist in the first place.

Our proficiency in setting goals is edited by cognitive abilities known as executive functions. These are the skills that include evaluation, decision making, organization, and planning. However, goal setting is only half the battle. We need specialized processes to enact these goals. Out ability to effectively carry out our goals is dependent on an assemblage of cognitive abilities referred to in the book as cognitive control. This includes attention, working memory, and goal management. Our ability to set high-level goals does not necessarily mean that it is inevitable that we are overwhelmed by goal interference. It is conceivable that the goal-enactment abilities of our brain evolved alongside our goal-setting abilities to offset any negative impact of goal interference. The authors conclude that this is not what seems to have happened. Our cognitive control abilities that are necessary for the enactment of our goals have not evolved to the same degrees as the executive function required for goal setting.

The authors continue, “ Our cognitive control is really quite limited: we have a restricted ability to distribute, divide and sustain attention; actively hold detained information mind; and concurrently manage or even rapidly switch between competing goals.”

The authors note that “In many ways, we are ancient brains in a high-tech world.”

 

A Review of The Brain

November 12, 2015

The Brain is a book by David Eagleman.  The subtitle is “The Story of You.”  I gave the book 5 stars in my review on Amazon.  I wrote, “Anyone with a brain should read this book.  (Knowing) how the brain works is essential for the individual.  It also provides the basis for more effective government.”

The brain is the most important organ of the body (even though Woody Allen said it was his second favorite organ).  It informs us who we are.  Growing the brain provides us with additional knowledge and know how.  This much should be obvious.  However, when I see the problems we have, many of them are due to a lack of knowledge as to how our brain works.  That is what I meant by writing, “provides the basis for more effective government.

Eagleman writes, “Your brain is a relentless shapeshifter, constantly rewriting its own circuitry—and because your experiences are unique, so are the vast detailed patterns in your neural networks.  Because they continue to change your whole life, your identity is a moving target;  it never reaches an endpoint.  Eagleman explains how the brain develops and why the teen brain is set up to take risks.  Moving from childhood into adolescence, the brain shows an increasing response to rewards in areas related to pleasure seeking such as the nucleus accumbens.  In deems this activity is as high as in adults but activity in the orbitofrontal cortex, which is important  for executive decision making, attention, and simulating future experiences, is still about the same in teens as it is in children.  In fact, the prefrontal cortex, which is important for executive decisions, dos not mature until the mide-twenties, which provides adequate time for ruining our lives.  The brain continues to change physically as we learn new skills and information and memories themselves change each time they are summoned.  Memories are highly fallible and can be easily changed, which are facts not generally recognized by courts of law.

Eagleman includes a study of nuns who are willing to provide their brains for study after they die.  The nuns are tested while they are living and then autopsies are provided after they die.  They have found brains that are wracked by the defining neurofibril tangles and amyloid plaques of Alzheimer’s, but these  nuns never exhibited any of the symptoms of Alzheimer’s and remained mentally sharp until they died.  The nuns are not unique, other autopsies on other populations have resulted in similar findings.  The nuns interacted with each other, they had growth mindsets, and the meditated with prayer, presumably continuing to develop a cognitive reserve.  Yet Alzheimer’s research is focused on finding drugs to destroy or inhibit the growth of these physical symptoms as well as tests to detect the early development of these symptoms.  There are no drugs that can cure Alzheimer’s, and there are knowledgeable scientists who believe that there never will be such drugs (See the healthy memory blog post “The Myth of Alzheimer’s).  All that drugs can do is to slow the progress of Alzheimer’s.  In my view all this does is to prolong the suffering.

People need to understand that reality is an illusion.  True there is a real physical world, but we learn of this world via our senses, which are used to build up mental models.  Moreover, each of us has different views of this world, one that changes, or should change with experience and learning.  People who fail to understand this are naive realists, and one of the reasons for the problems of the world is the existence of these naive realists.  Eagleman explains how this learning takes place.   He notes that the brain is like a city.  When one looks at a city one sees buildings, roads, structures and so forth, but to find out where businesses are and how the city actually functions, it is due to interactions of different parts of the city.  The same is true of the brain.  It is a complicated structure that operates by intercommunicates among the different elements.  Most of these intercommunicates are unconscious, but some raise to he level of consciousness.

It is interesting to note that the visual system has some connections that feed forward and others that feed backwards.  What makes this interesting is that the ratio of connections feeding backward are ten times those of feeding forward.  This provides a strong indication how much we know bears on what we actually see.  Expectations weigh heavily on what we see.

Our brain is a storyteller.  It serves us narratives that bear on what we believe.  Ascertaining truth usually entails the critical thinking about different narratives.

We are unaware of the vast majority of the activity in our brains.  It remains below our level of consciousness, so one may well ask, who is in control.  A good way of thinking about this is to regard our consciousness as an executive office that makes important decisions.  There are some who believe that our conscious minds are only along for the ride, but I am not one of them (see the healthy memory blog post, “Free Will”).

The healthy memory blog argues that the memory is a device for time travel and Eagleman agrees.  It is a device that travels back to the past to plan for the future.  This involves generating scenarios for what might happen in the future.  The same parts of the brain that are involved in remembering are used in imaging alternative  futures.

Eagleman writes,”Although we typically feel independent, each of our brains operates in a rich web of interactions with one another—so much that we can plausibly look at the accomplishments of our species as the deeds of a single, shifting mega-organism.”  A subsequent healthy memory blog post will expound more on this topic.

The final chapter is titled “Who Will We Be?” and addresses the possibility of our transcending our biological selves.  This is an interesting chapter, but we might be constrained by our limited levels of attention.  We can only consciously attend to several items at once.  We become skilled or fluent via many hours of practice.  Can this bottleneck be transcended?  This question is key to the answer to the question of whether we can transcend our biological selves.

There is a PBS series based on this book, that I strongly recommend.  I recommend both reading the book at watching the series multiple times.  Understanding our brains is of paramount importance.

The Benefits of Physical Exercise & Cognitive Training on the Executive Function of Older Adults

February 22, 2015

As the name implies, executive function is important.  It involves the prefrontal cortex, which has a high level of neural plasticity (Miller, E.K., & Cohen, D.J. (2001),  “An Integrative Theory of Prefrontal Cortex Function,” Annual Review of Neuroscience, 24, 167-201. doi:10.1146/annurev.neuro.24.1.167), meaning that it is amenable to training.  This current blog post provides a very brief summary of an article by Justin E. Karr, Corson N. Areshenkoff, Phillipe Rast, and Mauricio A. Garcia-Barrera titled “An Empirical Comparison of the Therapeutic Benefits of Physical Exercise and Cognitive Training on the Executive Functions of Older Adults:  A Meta-Analysis of Controlled Trials” in Neuropsychology (2014), 829.845.

A meta-analysis is an analysis of a large body of research.  This one involved 46 studies, 23 involving physical exercise (PE), 21 cognitive training (CT), and 2 involving both.  Cognitive training did not work for individuals who were already cognitively impaired.  Otherwise, both types of training improved executive functions, but CT presented potential advantages for specific types of cognitive functions.  The immediately previous post discussed these executive functions:  working memory, inhibition, executive attention, problem solving, and fluency.  The review found that cognitive training on problem solving had the largest beneficial effect on the measure of Independent Activities of Daily Living (IADL).

Although the study found that the effects of cognitive training were larger than physical exercise, they qualified this conclusion.  I would contend that it is foolish to argue which is better.  They both provide benefit.  Presumably the major benefit from physical exercise is due to aerobic activity increasing oxygen flow to the brain.  I am curious as to whether any activity that increases respiration might be beneficial,  laughing for example.  Feel free to add whatever techniques you can think of for increasing respiration.  I think it would be worthwhile for researchers to explore possible benefits of these types of activities.  One of the primary advantages of cognitive training is that they can be targeted at specific cognitive functions.  Further research could be explored at designing training to improve specific functions where training is most needed.  The types of training might vary among individuals.  This meta-view has found that, general speaking, problem solving skills had the largest effect.

© Douglas Griffith and healthymemory.wordpress.com, 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Five Constructs for Executive-Related Cognitive Abilities

February 18, 2015

This post addresses five constructs, or factors, dealing with executive related cognitive abilities.  They are obviously important because these are cognitive abilities at the executive level.  They also have special relevance for aging memory.  These factors play an important role in the assessment of Independent Activities of Daily Living (IADL).  IADL plays an important role in determining whether individuals are capable of living independently.  These factors are working memory, inhibition, executive at the attention, problem solving, and fluency.  Each factor will be briefly explained and discussed with respect to the healthy memory blog, “The Myth of Cognitive Decline.”

The most common example given of working memory is trying to remember a phone number you have just be given or read until it is dialed.  This is the magic number of 7 plus or minus two that has been revised down to five plus or minus two.  Actually, the size of the individual items affects the number that can be remembered.  Information must be rehearsed or actively used  or the information will be lost.  As the “Myth of Cognitive Decline” is addressing the phenomena of long term memory, working memory is not part of the myth.  Working memory does tend to decline as we age, although research has been done to demonstrate that it can be enhanced.

Inhibition refers to irrelevant information coming to mind when you are trying to remember or solve a problem.  This does increase as we age.  And it is the large amount of information held in long term memory that the “Myth of Cognitive Decline” addresses, that is likely increasing inhibition.  Simply put, there is more information to serve as the source of inhibition.  Given enough time, this inhibition can be overcome.

Executive attention refers to the managing and selection of information in trying to perform some task or to solve some problem.  The problem here for us as we age is that there is more information to attend to.  Again, given enough time, decreases in this ability can be overcome.

Problem solving refers to the marshaling of attention to solve  a problem.  Examples of problems addressed with IADL are planning a meal, planning a trip, managing finances, and so forth.  Although the more experienced mind has more information to solve problems, when there are time constraints, the additional information can be a problem as captured in the statement, “too much knowledge for one’s own good.”

Fluency is the ability to generate ideas or certain types of words (words beginning with “q”, vegetables, and so forth).  Here the older brain is at an advantage, but again, the pressures of time constraints can create problems.  A caveat to the “Myth f Cognitive Decline” is “given enough time.”

Recall, particularly of information from longer term memory, often involves problem solving.  When trying to remember the forgotten name of a particular actor for example, one might try to remember the movies the actor was in, the dates of the movies, and other actors.  Sometimes remembering a particular sound can help in the generation of candidate names.  What is interesting about these attempts is that the memory will suddenly pop into mind hours or days later.  Apparently memory search has been continuing in our non-conscious minds.  This is one of the reasons I think that these periodic memory searches contribute to memory health.  When we do these searches we are activating long unused memory circuits and reactivating them.  I have no carefully controlled research to back up my conjecture, but I think it is a compelling conjecture.  Perhaps some graduate student will undertake this research for a Master’s Degree or Ph.D.

© Douglas Griffith and healthymemory.wordpress.com, 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

The Dangers of MultiTasking

March 4, 2012

A common notion is that young people who have grown up with technology have effectively rewired their brains for multitasking and are proficient at multitasking. This common notion is wrong according to research.1 A group of psychologists at UCLA led by Karin Foerde conducted an experiment to determine whether multitasking impairs learning. They trained 14 participants to perform a single task, predicting the weather based on certain cues. Their brains were scanned while they did this. Their brains were also scanned while they did this task and had a secondary task added to it, keeping count of the number of high pitched auditory tones in a series of auditory tones.

The participants were able to perform both tasks, but they paid a cognitive cost when they performed both tasks. When they performed the weather task alone they used a region of the brain that enables us to apply knowledge gained to other situations when needed (System 2 processing). However, when they performed both tasks at once, they activated a part of their brain linked with habit learning (System 1 processing), The psychologist William James knew this more than one hundred years ago when he wrote that “we can’t easily do more than one thing at once, “unless the processes are very habitual.”2 So if anything surprising or unusual is encountered, it is likely to be missed.

Subsequently, a group of researchers at Stanford classified a group of participants as whether heavy or light multitaskers. They administered a series of cognitive tests, each designed to measure some aspect of distractibility to see which group handled the load better. They were surprised to find that compared to light multitaskers, the heavy multitaskers did a worse job filtering out irrelevant distractions, had a harder time ignoring irrelevant memories, and took a longer time switch from one task to another. Now both groups performed the same on tasks when there were no distractions. But it appears that the heavy multitaskers “may be sacrificing performance on the primary task to let in other sources of information.3

The problem is that people typically are not aware of this loss in performance. Other researchers4 found that people who were high in real-world multitasking not only had lower working-memory capacity, but also were more impulsive and sensation-seeking. Worse yet, they rated their own ability to multitask as higher than average. So their perceived ability and actual ability to multitask were inversely related. It appears that overconfidence rather than skill drives this proliferation of multitasking. The fear is that academic activity will receive less focused time, resulting in cursory processing of information and shoddy outcomes.

1Jaffe, E. (2012). Rewired: Cognition in the Digital Age. Observer, 25,2, 16-20. A Publication of the Association for Psychological Science.

2James, W. (1890). The Principles of Psycholog. NY: Holt.

3. Ophir, E., Nass, C., & Wagner, E.D., Cognitive Control in Media Multitaskers. Proceedings of the National Academy of Sciences, 106, 15583-15587.

4Strayer, D.L., & Watson, J.M., (2012).Supertaskers and the Multitasking Brain. Scientific American Mind, March/April, 22-29.

© Douglas Griffith and healthymemory.wordpress.com, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.

Computer Use and Cognition Across Adulthood

February 19, 2012

The results of the first national population-based investigation of the association between computer activity and cognitive performance across adulthood has been published.1 This study involved a large national sample (N = 2,671) of adults ranging from 32 to 84 years old. Cognition was assessed by telephone with the Brief Test of Adult Cognition.2 Executive function was assessed with the Stop and Go Switch Task.3 Individuals who used the computer frequently scored significantly higher than those who seldom used the computer. The variables of age, sex, education, and health status were statistically controlled so this result maintained across all these variables. Greater computer use was also associated with better executive function on a task-switching test. Again this result held up across the basic cognitive and demographic variables. So computer activity is associated with good cognitive function and executive control across adulthood and into old age. Individuals with low intellectual ability benefited even more from computer use.

Unfortunately, computer usage declines across age. Of course, the personal computer is a relatively new technology, one that was not available earlier in the lifespans of many. It is hoped that this will be less of a problem in the future for those who have had access to computer technology throughout their lives. There are issues with perceptual and motor decline as we age, and computer technology needs to accommodate them. It is not surprising that that people with lower income and less education are less likely to use computers. It would be good to develop programs for these people that provide not only ready access to computers, but also to training in their use.

And if you have a computer, use it, don’t lose cognitive functioning or executive control. The internet provides a good vehicle for cognitive growth. It includes a vast amount of transactive memory. The computer also provides a good means of interacting with your fellow humans, although it should not be the exclusive means of interacting with fellow humans.

1Tun, P.A., & Lachman, M.E. (2010). The Association Between Computer Use and Cognition Across Adulthood: Use It So You Won’t Lose It? Psychology and Aging. 25, 560-568.

2Tun, P.A., & Lachman, M.E. (2006). Telephone Assessment of Cognitive Function in Adulthood: The Brief Test of Adult Cognition by Telephone. Age and Ageing, 35, 629-632.

3Tun, P.A., & Lachman, M.E. (2008). Age Differences in Reaction Time in a National Telephone Sample of Adults: Task Complexity, Education, and Sex Matter. Developmental Psychology, 44, 1421-1429. doi:10.1037/a00128456

© Douglas Griffith and healthymemory.wordpress.com, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and healthymemory.wordpress.com with appropriate and specific direction to the original content.