AG Bell Symposium 2009: Friday Sessions

GENERAL SESSION: Development of Executive Control in Preschool Children (Dr. Kimberly Andrews Espy, Associate Vice Chancellor for Research, and Professor, Department of Psychology, University of Nebraska-Lincoln)


 

Dr. Espy is one of the leading researchers in the field of executive function development among children who are preschool-aged.  She described executive function as, “Higher order, regulatory, goal-directed cognition and behavior,” or, more simply, “How we learn to learn.”  Preschoolers develop skills like organization, attention, inhibition, and working memory long before they learn to read or do algebra, but these foundation skills lay the groundwork for learning that they’ll do throughout life!

 

Executive function skills are thought to occur in the prefrontal cortex.  This area of the brain has a very long period of maturation, starting before birth an continuing into your 20s.  This long growth period is both good and bad.  The good news is, if we catch EF problems in children, we have time to “change the brain” by intervening.  The bad news is that this long period of development means that this area has a protracted length of vulnerability to injury or disturbance.

 

Dr. Espy and her colleagues have done some incredibly research on EF in preschoolers, and developed some elegant mathematical models to interpret their results.  (Okay, I realize that these mathematical models are only “elegant” if you’re a nerd like me, but bear with me here!)  Basically, Dr. Espy theorized that many of the assessments we give to children, like language assessments, IQ tests, cognitive measures, etc., test both content AND executive function skills.  For example, the PPVT (Peabody Picture Vocabulary Test) assesses not only a child’s knowledge and use of vocabulary words, but also the child’s ability to keep the instructions in their working memory, inhibit competing factors/distractions, attend to the stimulus picture, and organize the information in their heads.  Drawing from preschoolers’ scores on a variety of tests, Dr. Espy and her team were able to pick apart the measures based on content vs. EF skills and see what relationships, if any, existed between factors in these preschoolers’ environment and their abilities, and their development of executive function skills.

 

Some relationships Dr. Espy found include:

  • EF skills are all bound together, at least in preschoolers.  They may develop in different ways as children age or in adults, but preschoolers tend to have a general level of EF skills (i.e. equally good/bad at organizing, remembering, planning, etc. than having different levels of ability with each skill).

 

  • EF control scores on psychometric evaluations were higher (“better”) for girls, and girls seem to be able to draw on these skills more in everyday life (per parent behavior report surveys).

 

  • Inattention in girls is not as tied to “acting out” behaviors.  Inattentive boys are more likely to show such disruptive behaviors.

 

  • Environmental stressors (poverty, poor family environment, etc.) predicted crystallized knowledge (knowing the “content”) but not overall executive functioning skills.  (So these children have the basic skills, but are not in environments that are filled with rich language and learning experiences to help them build on that foundation).

 

  • A family’s size of social network and amount of social/community support are tied positively to children’s EF skills — perhaps with support and help, families are more able to structure their children’s lives to lay the groundwork for EF skill development.  For example, if you have grandparents or caring babysitters who give your child structure and support while you are gone rather than plopping them in front of the TV, you are going to be better able to reinforce these organizational skills when you have time to spend with your child.

 

  • It is hypothesized that there is a genetic and biochemical component to frontal lobe, and thus executive function, development, but the exact gene(s)/mechanism(s) are not yet known.

 

  • Premature babies, even “low risk” preemies who don’t spend long periods in the NICU, are about 20% more likely than children born at full-term to experience executive function issues that may impact their academic and behavioral success.  This may be due to the higher incidence of brain bleeds and/or bonding/social isolation risks often experienced by children in the NICU.

 

Dr. Espy noted that while much of our concern with at-risk children, especially those who are deaf or hard of hearing, focuses on reading development, executive function is also correlated with MATH skills.  In fact, inhibitory skills (EF — can you “inhibit” behaviors that distract you from your task) in preschoolers were more highly correlated with math abilities than the children’s working memory.

 

 

Executive function matters because:

  • EF skills support regulatory behavior in the real world.  There is a strong correlation between a child’s executive skills and parents’ reports of their behavior at home and in school.

 

  • EF skills in young children predict later math proficiency.

 

  • EF skills differ meaningfully among individual children — different pathologies/etiologies (even different etiologies, or causes, of deafness) may manifest in different executive function deficits.

 

  • Awareness of EF — how it works well and what happens when there are problems — can help us identify (and help!) at-risk children.

 

 

PANEL DISCUSSION (Kimberly Andrews Espy, Ph.D., Mitchell Sommers, Ph.D., Melody Harrison, Ph.D., and Peter K. Isquith, Ph.D.)

The panel of professionals gave comments on Dr. Espy’s presentation, and then opened up the microphones for questions from audience members.  Several points that were mentioned include:

  • Because the development of the prefrontal cortex continues over time, you can’t just work on establishing EF skills in a 3-year-old, and, once they establish preschool-appropriate skills, say, “Okay!  We’re done!”  Development of EF skills is a continual process that we must adapt as the child’s environment becomes more challenging and the child is more mature and able to handle higher expectations and more complex tasks.

 

  • The old “common knowledge” was that it was “better” to have brain injury early in life because the brain has higher plasticity in young children.  These experts said that is not valid because, though a child who has some insult to the brain early in life may appear to be “okay,” there are often soft skill deficits that show up later in life.

 

  • The architecture of the brain is shaped by the experiences of the brain — NONE of this is set in stone, so what we do when we work with children can either help or hurt their development of EF skills.

 

  • The frontal lobe doesn’t exist in isolation — it is connected to, and interacts with, the other parts of the brain, so EF is an overall brain experience, and can be hindered by problems in areas other than the frontal lobe.

 

  • The prefrontal cortex has a role in children’s ability to pick up on codes/relationships in the environment — like the “code” of language, especially syntax.  Executive function is closely tied to early reading and language skills.  As a child becomes more skilled at language, the process becomes more automatic and the “cognitive load,” or stress, on the frontal lobe is reduced.  The more we talk to and read to children (and give them chances to talk and read and write, too!), the more “over-learned” the process becomes, and the more automatic it becomes in the brain!

 

  • For a child with hearing loss, listening to a teacher speak in a noisy classroom is a taxing exercise of executive function.  The child must discern the important information (teacher’s voice) and inhibit the processing of unimportant things (noise).  The EF system has to work overtime, which means it is less able to apply to other learning tasks.  If all of your attention is focused on just hearing the message, you can’t possibly devote all the brain power you need to the subject matter at hand.  How do we help with this?  Modifications to the environment (FM, soundfield, acoustically treated classrooms) and teaching style (pre-teaching, repetition, clear, direct speech).

 

One of the best take-away messages from the panel discussion was this, “A test is just a window to the brain.”  So, psychometric assessments can be fantastic and very useful, but they are not labels, just tools to help us get closer and closer to figuring out where the child is, brain-wise, and how we can help them get to where they need to be!

 

 

WORKSHOP: Assessment of Executive Functions and Applying the Results in Everyday Practice (Peter K. Isquith, Ph.D., Pediatric Neuropsychology, Hanover Road Professional Center)

Dr. Isquith gave an example of an exercise to increase executive function skills and awareness of those skills in children.  Before doing an activity (any activity), ask the child:

  • What is your goal?

 

  • How would you go about doing that? (Have child generate a few different ways to solve the problem.)

 

  • Which one (plan) is going to work best?

 

  • On a scale of 1-10, how do you think you’re going to do with this plan and activity?

 

  • [after the activity] What worked here?  What would you do differently next time?

 

  • [after] On a scale of 1-10, how did you end up doing?

 

This simple series of questions has the adult walk the child through the steps of planning, organizing, and assessing their own behaviors.  The adult provides a scaffold for the child to develop executive function skills.

 

 

WORKSHOP: Communicating with Hearing-Impaired Older Adults: What Should I Know about Executive Functioning (Mitchell Sommers, Ph.D., Associate Professor, Department of Psychology, Washington University in St. Louis)

 

Why is it that so many older people with hearing loss complain, “I hear, but I don’t understand!”?  Why do so many people who start wearing hearing aids later in life end up shoving them in a drawer and never using them again?  Why is it that, with all of the cosmetic and technological improvements in hearing aids since the 1950s, the same number (about half) of people who receive hearing aids now as did then, abandon them less than a year later?  Why is it that two people with very similar audiograms can have very different speech perception results?

 

According to Dr. Sommers, the answers to these questions may be found in the study of executive function.  In ideal (quiet, single-talker) conditions, the audiogram, and other “concrete” measures of hearing loss may be our best clues to how well someone will perform in a speech perception task… but life is hardly ever an ideal situation.  In noisy environments, or environments with multiple, unfamiliar speakers, the audiogram alone will not give you as many clues as to how a person with hearing loss will perform.  Some of this has to do with executive function — the ability to inhibit (suppress) unimportant noises, and the capacity of working memory to hold previously heard information in the brain and to use it to piece together the message for communication.

 

Dr. Sommers explained the “Neighborhood Activation Model of Speech” (Luce and Pisoni, 1998), which says:

  • Words differ in their intelligibility.

 

  • When you hear a word, your brain “activates” all of the possible words that it could be, all of the words that sound like what you just heard.

 

  • You must inhibit, or suppress, those competing words to decide the correct word that you just heard.

 

  • Some words, like “cat,” activate a huge “neighborhood” of words (bat, fat, hat, mat, pat, sat, rat, etc.).  These are “hard” words for speech discrimination.

 

  • Other words, the “easy” words, have smaller neighborhoods.  For example, can you think of anything that sounds like “orange”???

 

In Dr. Sommers’ research, older adults with hearing loss did best with “hard” words when given semantic context.  It was much easier for the seniors to know that they heard the word “shark” when it was presented in the sentence, “He was bit by a _____” than when the sentence given was, “He was thinking about a _____”.  Older people with hearing loss also had higher speech perception when talking with a familiar speaker.  This may have to do with working memory and inhibition, both of which are crucial executive function skills.  Thus, different outcomes in elderly hearing aid users with similar levels of hearing loss may be due to cognitive decline and lower executive function skills.  In these cases, problems with speech perception may not be tied to hearing loss alone.

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