Posts tagged attention disorders
Articles and news from the latest research reports.
Paying closer attention to attention
Ellen’s (not her real name) adoptive parents weren’t surprised when the school counselor suggested that she might have attention deficit hyperactivity disorder (ADHD).
Several professionals had made this suggestion over the years. Given that homework led to one explosion after another, and that at school Ellen, who is eleven, spent her days jiggling up and down in her seat, unable to concentrate for more than ten minutes, it seemed a reasonable assumption. Yet her parents always felt that ADHD didn’t quite capture the extent of Ellen’s issues over the years. Fortunately the school counsellor was familiar with fetal alcohol spectrum disorder (FASD). When she learned that Ellen’s birth mother had consumed alcohol during pregnancy, she raised the possibility that Ellen’s problems could be attributable to FASD and referred her for further assessment.
It’s a familiar story, and most of us reading about Ellen would assume that she did indeed suffer from ADHD.
But now researchers from McGill have suggested that there may be an overreporting of attention problems in children with FASD, simply because parents and teachers are using a misplaced basis for comparison. They are testing and comparing children with FASD with children of the same physical or chronological age, rather than with children of the same mental age, which is often quite a lot younger.
“Because the link between fetal alcohol syndrome and ADHD is so commonly described in the literature, both parents and teachers are more likely to expect these children to have attention problems,” says Prof. Jacob Burack, a professor in McGill’s Dept. of Educational and Counselling Psychology and the senior author on a recent study on the subject. “But what teachers often don’t recognize is that although the child they are dealing with is eleven years old in chronological terms, they are actually functioning at the developmental age of an eight-year old. That’s a pretty big difference. And when you use mental age as the basis of comparison, many of the attention problems that have been described in children with FASD no longer seem of primary importance.”
The researchers recruited children with FASD whose average chronological age was just under twelve years old. But their average mental age, determined by standard tests, was actually closer to nine-and-a-half years old. (The children were recruited through the Asante Centre for Fetal Alcohol Syndrome in British Columbia, and though the number of children studied may appear small, this is a fairly typical size for studies on FASD, given the difficulties of the diagnostic process.)
These children were then compared with children who were developing typically and whose average chronological age was about eight-and-a-half years old and whose average mental age was similar to that of the group of children diagnosed with FASD.
After using tests to measure specific aspects of attention, the researchers then compared the performance of children with FASD on these tests with the results of children of the same mental age. What they found was that while children like Ellen had difficulties with certain kinds of attention skills, notably in terms of shifting attention from one object to another, there were other areas, such as focus, where they had no significant difficulties at all. So, if we were to compare these aspects of attention to a hockey game, typically these children would have no difficulty focusing on the puck in the arena, but would have problems following the puck being passed from one player to another.
This suggests to Dr. Kimberly Lane, the PhD student who conducted the research, that there is a need to develop a more nuanced understanding of attention skills. “We use words like attention loosely, but it’s really an umbrella term that covers various aspects of attending to different people or events or environments,” says Dr. Lane. “By using more complex assessment techniques of various aspects of attention it will be possible to get a better picture of the attention difficulties faced by children with FASD,” she adds.
“But no matter what the tests say, it’s important for teachers and parents to understand that.the difficulties these children have with attention may be less important than their more general problems, and we need to work with them as they are.”
(Source: mcgill.ca)
Scientists discover brain’s anti-distraction system
Two Simon Fraser University psychologists have made a brain-related discovery that could revolutionize doctors’ perception and treatment of attention-deficit disorders.
This discovery opens up the possibility that environmental and/or genetic factors may hinder or suppress a specific brain activity that the researchers have identified as helping us prevent distraction.
The Journal of Neuroscience has just published a paper about the discovery by John McDonald, an associate professor of psychology and his doctoral student John Gaspar, who made the discovery during his master’s thesis research.
This is the first study to reveal our brains rely on an active suppression mechanism to avoid being distracted by salient irrelevant information when we want to focus on a particular item or task.
McDonald, a Canada Research Chair in Cognitive Neuroscience, and other scientists first discovered the existence of the specific neural index of suppression in his lab in 2009. But, until now, little was known about how it helps us ignore visual distractions.
“This is an important discovery for neuroscientists and psychologists because most contemporary ideas of attention highlight brain processes that are involved in picking out relevant objects from the visual field. It’s like finding Waldo in a Where’s Waldo illustration,” says Gaspar, the study’s lead author.
“Our results show clearly that this is only one part of the equation and that active suppression of the irrelevant objects is another important part.”
Given the proliferation of distracting consumer devices in our technology-driven, fast-paced society, the psychologists say their discovery could help scientists and health care professionals better treat individuals with distraction-related attentional deficits.
“Distraction is a leading cause of injury and death in driving and other high-stakes environments,” notes McDonald, the study’s senior author. “There are individual differences in the ability to deal with distraction. New electronic products are designed to grab attention. Suppressing such signals takes effort, and sometimes people can’t seem to do it.
“Moreover, disorders associated with attention deficits, such as ADHD and schizophrenia, may turn out to be due to difficulties in suppressing irrelevant objects rather than difficulty selecting relevant ones.”
The researchers are now turning their attention to understanding how we deal with distraction. They’re looking at when and why we can’t suppress potentially distracting objects, whether some of us are better at doing so and why that is the case.
“There’s evidence that attentional abilities decline with age and that women are better than men at certain visual attentional tasks,” says Gaspar, the study’s first author.
The study was based on three experiments in which 47 students performed an attention-demanding visual search task. Their mean age was 21. The researchers studied their neural processes related to attention, distraction and suppression by recording electrical brain signals from sensors embedded in a cap they wore.
Pay attention: How we focus and concentrate
Scientists at Newcastle University have shed new light on how the brain tunes in to relevant information.
Publishing in Neuron, the team reveal the interplay of brain chemicals which help us pay attention in work funded by the Wellcome Trust and BBSRC.
By changing the way neurons respond to external stimuli we improve our perceptual abilities. While these changes can affect the strength of a neuronal response, they can also affect the fidelity of that response.
Lead author Alex Thiele, Professor of Visual Neuroscience explains: “When you communicate with others, you can make yourself better heard by speaking louder or by speaking more clearly. Neurons appear to do similar things when we’re paying attention. They send their message more intensely to their partners, which compares to speaking louder. But more importantly, they also increase the fidelity of their message, which compares to speaking more clearly.
“Our earlier work has shown that attention is able to affect the intensity of responses – in effect the loudness - by means of the brain chemical acetylcholine. Now we have shown that the fidelity of the response is altered by a different brain chemical system.”
In the paper, the team reveal that the quality of the response is altered by means of glutamate coupling to NMDA receptors (a molecular device that mediates communication between neurons). Carried out in a primate model, these studies for the first time isolate different attention mechanisms at the receptor level.
The research builds on the team’s previous studies and has potentially significant implications not only for our understanding of how our brains work but also give an insight into conditions such as schizophrenia, Alzheimer’s disease and attention deficit disorder, and may aid in the development of treatments for them.
Study on ADHD, Provide New Insight Into Prevalence and Treatment Needs
Attention Deficit Hyperactivity Disorder is both under and over diagnosed.
That’s the result of one of the largest studies conducted on ADHD in the United States, published in the Journal of Attention Disorders.
A substantial number of children being treated for ADHD may not have the disorder, while many children who do have the symptoms are going untreated, according to the 10-year Project to Learn about ADHD in Youth (PLAY) study funded by the National Center on Birth Defects and Developmental Disabilities of the Centers of Disease Control and Prevention
"Childhood ADHD is a major public health problem. Many studies rely on parent reporting of an ADHD diagnosis, which is a function of both the child’s access to care in order to be diagnosed, and the parent’s perception that there is a problem," said Robert McKeown, of the University of South Carolina’s Arnold School of Public Health, who led the South Carolina portion of the study.
"Further complicating our understanding of the prevalence of ADHD and its treatment is that the diagnosis often is made by a clinician who has little experience assessing and diagnosing mental disorders. As a result, ADHD is both under and over diagnosed," said McKeown, distinguished professor emeritus in the department of epidemiology and biostatistics.
The study, conducted between 2002-2012, was a collaborative research project with the University of South Carolina’s Arnold School and School of Medicine and the University of Oklahoma’s Health Sciences Center.
"To our knowledge, this is the largest community-based epidemiologic study of ADHD to date," McKeown said.
A mysterious region deep in the human brain could be where we sort through the onslaught of stimuli from the outside world and focus on the information most important to our behavior and survival, Princeton University researchers have found.
The researchers report in the journal Science that an area of our brain called the pulvinar regulates communication between clusters of brain cells as our brain focuses on the people and objects that need our attention. Like a switchboard operator, the pulvinar makes sure that separate areas of the visual cortex — which processes visual information — are communicating about the same external information, explained lead author Yuri Saalmann, an associate research scholar in the Princeton Neuroscience Institute (PNI). Without guidance from the pulvinar, an important observation such as an oncoming bus as one is crossing the street could get lost in a jumble of other stimuli.
Saalmann said these findings on how the brain transmits information could lead to new ways of understanding and treating attention-related disorders, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia.