Dr. Reesman and Dr. Plotkin
Your Brain’s Filter:
The Importance of Attention in Managing Sensory Information
Think about your socks for a minute. Do you realize that there is a seam on the toe? What about the cuff of the socks? Notice those? Chances are, probably not. Why? Your brain is very good at filtering out sensory information that is not pertinent to what you need to be attending to. For most of us, we do this effortlessly and without a second thought. However, for children, this type of attentional process is learned and develops over time as the brain matures with age and experience. The ability to selectively attend, focus, and filter out information from the world around them depends on many complex and sophisticated brain networks that allow us to take in information and make sense of it.
As we take in information, particularly sensory information; our brain must first identify that there is “something” out there that requires our attention, whether it be a bright red stop sign, a tap on the shoulder, a flick of the lights, or a bark of the dog waiting to go outside. Then, we must attend to that information at the expense of other information. For example, have you ever noticed what you do when you are searching for an address or trying to find your way in a new neighborhood? Most people tend to turn down the radio or hang up the cell phone in order to focus on finding their way. We do this almost instinctively, and use this to our advantage to try and maximize our attention to the most pressing or important demand to our attentional system. In thinking about the development of these skills, the brains of children go through dramatic change from infancy to late adolescence. In school-age children there is a virtual explosion and increase in connections between nerve cells (or neurons) that helps children to make new associations and promote new learning. Over time, as children progress into adolescence, their brains also undergo dramatic change to become more efficient and automatic. This is done as the connections between brain cells that are not often being used tend to die off, making the neuronal connections that are frequently used as efficient as possible. Neuroscientists refer to this process as pruning – just like the pruning of the bushes in your front yard to make them more orderly. Our attentional system is actually quite complex. Focusing refers to our ability to select target information from our environment while at the same time inhibiting irrelevant information. Our ability to maintain that focus is described as sustained attention and shifting is our capacity to change our focus. Our attentional system has a limited-capacity, suggesting we are limited in how many things we can attend to at once.
These aspects of attention show major developmental changes throughout childhood. It is thought that as early as six months of age and on through development, the frontal region of our brains becomes more and more functional, as areas within the prefrontal cortex begin to play a significant role in maintaining our attention.
Our attentional system plays an important role in how we deal with sensory information. Countless amounts of sensory signals are entering our brain at once, whether it is the sight of a florescent light bulb flickering or the smell of a burning building nearby. It is the job of our prefrontal cortex, where our attentional system primarily lives, to pick and choose which sensory information is important to attend to and what is less important. Because our attentional system is already quite limited in its capacity, most of the time our brains automatically tune out information that is not pertinent, in order for our attentional resources to be preserved for input that is important, like what your teacher is pointing to.
Children with hearing loss will go through the same developmental stages in terms of maturation of the attentional system. However; children with hearing loss who have additional developmental concerns such as attention deficit hyperactivity disorder (ADHD), autism, or seizures may have a different trajectory of how their brain will develop the capacity to attend to information efficiently and automatize this process over time. This is not to say that they cannot or will not develop these skills, but it may be at a different rate than their peers. Or, they may require some accommodations to their environment to be most successful.
Hearing aids and cochlear implants certainly ramp up the sensory information available to children with hearing loss. In many situations, this stimulation is new and may require the child to learn to attend to what is important, tune out the irrelevant information and keep their focus sustained over time, even when there are distractions like a fan on a heating system blowing in the background. This focusing and selection of auditory information when a child is using amplification takes a lot of cognitive energy and resources since the process may not yet be automatic. Just like learning any new skill, such as learning how to ride a bicycle, the skill takes practice and effort at first, but over time becomes more automatic in order for the child to ultimately divide attentional resources between more than one task. For some children, this work is tiring as it oftentimes requires them to attend to multiple sources of information, such as visual input from speechreading or sign language, auditory information, all the while trying to make sense of it. Imagine trying to play the word game Boggle, listen to Bach and play Bingo all at the same time; naturally, you might be tired after all of your cognitive resources have been depleted. Some children have more difficulty with aspects of their attentional systems, whether it is the child who has trouble with flexibly adjusting to small changes in stimulation or the child who has difficulty focusing on the relevant information. This all relates to what we think of as “sensory processing,” as our attention system is a requirement for being able to process any type of information we perceive. As neuropsychologists and professionals who care for children with hearing loss, we seek to educate our families about their children’s brain and how that relates to the behavior we see in the office, at home and in the classroom.
If Parents Have Concerns
As a parent, you may be concerned if your child displays an extreme over or under reaction to some type of stimulation (i.e., pain, temperature, sounds, and so on). If this sounds like you, first sit back and observe your child. Ask others if they also see this behavior to help look for a pattern about how often this occurs and if this behavior prevents or significantly interferes with your child’s day to day routine. Difficulties with sustaining attention when it is expected at an age-appropriate level and/or excessive hyperactive behavior may also raise a red flag. Your pediatrician may be able to provide some guidance on diagnosis and treatment options and psychologists can assist with examining for other associated issues and developing a comprehensive treatment plan. If you have concerns, be sure to discuss them with your child’s health care team and ask if these professionals have experience in working with children with hearing loss. Remember, you know your child best and if you notice something that keeps you up at night, it is always better to ask the question than to silently worry.
About the authors:
Dr. Plotkin is a post-doctoral fellow in the Department of Neuropsychology at the Kennedy Krieger Institute and Johns Hopkins University School of Medicine. She is a graduate of Gallaudet University and currently training in the Deafness Related Evaluations and More (DREAM) Clinic at the Kennedy Krieger Institute.
Dr. Reesman is a pediatric neuropsychologist in the Department of Neuropsychology at the Kennedy Krieger Institute and an Instructor of Psychiatry and Behavioral Sciences at the Johns Hopkins University School of Medicine. She directs and oversees the clinical and training activities of the DREAM Clinic.
For additional information on the DREAM Clinic, please see: http://www.kennedykrieger.org/patient-care/patient-care-programs/outpatient-programs/deafness-related-evaluations-and-more-dream -clinic