I recently reported that developing skill at video action games doesn’t seem to improve general multitasking ability, but perhaps another approach might be more successful. Meditation has, of course, been garnering growing evidence that it can help improve attentional control. A new study extends that research to multitasking in a realistic work setting.
I have said before that there is little evidence that working memory training has any wider benefits than to the skills being practiced. Occasionally a study arises that gets everyone all excited, but by and large training only benefits the skill being practiced — despite the fact that working memory underlies so many cognitive tasks, and limited working memory capacity is thought to negatively affect performance on so many tasks.
I’ve mentioned before that, for some few people, exercise doesn’t seem to have a benefit, and the benefits of exercise for fighting age-related cognitive decline may not apply to those carrying the Alzheimer’s gene.
A three-year study involving 3,034 Singaporean children and adolescents (aged 8-17) has found that those who spent more time playing video games subsequently had more attention problems, even when earlier attention problems, sex, age, race, and socioeconomic status were statistically controlled. Those who were more impulsive or had more attention problems subsequently spent more time playing video games, even when initial video game playing was statistically controlled.
A new analytical technique has revealed that the problem with children with ADHD is not so much that they are slower at responding to tasks, but rather that their response is inconsistent. The study of 25 children with ADHD and 24 typically developing peers found that on a task in which a number on one screen needed to be mentally added to another number shown on a second screen, those with ADHD were much less consistent in their response times, although the responses they did give were just as accurate. Higher levels of hyperactivity and restlessness or impulsivity (as measured by parent survey) correlated with more slower reaction times. The finding supports the idea that what underlies impaired working memory is a problem in how consistently a child with ADHD can respond during a working memory task.
Buzy, W. M., Medoff, D. R., & Schweitzer, J. B. (2009). Intra-Individual Variability Among Children with ADHD - on a Working Memory Task: An Ex-Gaussian Approach. Child Neuropsychology, 15(5), 441-441. Retrieved from http://www.informaworld.com/10.1080/09297040802646991
http://www.eurekalert.org/pub_releases/2009-03/uoc--ips032409.php
A study of 12 8- to 12-year-old boys with ADHD, and 11 of those without, has found that activity levels of those with ADHD increased significantly whenever they had to perform a task that placed demands on their working memory. In a highly stimulating environment where little working memory is required (such as watching a Star Wars video), those with ADHD kept just as still as their normal peers. It’s suggested that movement helps them stay alert enough to complete challenging tasks, and therefore trying to limit their activity (when non-destructive) is counterproductive. Providing written instructions, simplifying multi-step directions, and using poster checklists are all strategies that can be used to help children with ADHD learn without overwhelming their working memories.
Rapport, M., Bolden, J., Kofler, M., Sarver, D., Raiker, J., & Alderson, R. (2009). Hyperactivity in Boys with Attention-Deficit/Hyperactivity Disorder (ADHD): A Ubiquitous Core Symptom or Manifestation of Working Memory Deficits? Journal of Abnormal Child Psychology, 37(4), 521-534. Retrieved from http://dx.doi.org/10.1007/s10802-008-9287-8
http://www.eurekalert.org/pub_releases/2009-03/uocf-ush030909.php
A pilot study involving 10 middle school students with ADHD has found that those who participated in twice-daily 10 minute sessions of Transcendental Meditation for three months showed a dramatic reduction in stress and anxiety and improvements in ADHD symptoms and executive function. The effect was much greater than expected. ADHD children have a reduced ability to cope with stress.
A second, recently completed study has also found that three months practice of the technique resulted in significant positive changes in brain functioning during visual-motor skills, especially in the circuitry of the brain associated with attention and distractibility. After six months practice, measurements of distractibility moved into the normal range.
Grosswald, S.J., Stixrud, W.R., Travis, F. & Bateh, M.A. 2008. Use of the Transcendental Meditation technique to reduce symptoms of Attention Deficit Hyperactivity Disorder (ADHD) by reducing stress and anxiety: An exploratory study. Current Issues in Education, 10 (2)
http://www.eurekalert.org/pub_releases/2008-12/muom-tmr122408.php
Ritalin has been widely used for decades to treat attention deficit hyperactivity disorder (ADHD), but until now the mechanism of how it works hasn’t been well understood. Now a rat study has found that Ritalin, in low doses, fine-tunes the functioning of neurons in the prefrontal cortex, and has little effect elsewhere in the brain. It appears that Ritalin dramatically increases the sensitivity of neurons in the prefrontal cortex to signals coming from the hippocampus. However, in higher doses, prefrontal neurons stopped responding to incoming information, impairing cognition. Low doses also reinforced coordinated activity of neurons, and weakened activity that wasn't well coordinated. All of this suggests that Ritalin strengthens dominant and important signals within the prefrontal cortex, while lessening weaker signals that may act as distractors.
Devilbiss, D. M., & Berridge, C. W. (2008). Cognition-Enhancing Doses of Methylphenidate Preferentially Increase Prefrontal Cortex Neuronal Responsiveness. Biological Psychiatry, 64(7), 626-635. Retrieved from http://www.sciencedirect.com/science/article/B6T4S-4SW85G8-2/2/eb309c131fc9d0e94ce37980797f9c68
http://www.eurekalert.org/pub_releases/2008-06/uow-suh062408.php
The first large, longitudinal study of adolescents and ADHD has revealed that only about half of children diagnosed with attention-deficit hyperactivity disorder exhibit the cognitive defects commonly associated with the condition. Part of the explanation may lie in the fact that ADHD is simply the extreme end of a normal continuum of behavior that varies in the population, and its diagnosis is defined by where health professionals "draw the line" on this continuum. This finding suggests that behavior-rating scales alone are not sensitive enough to differentiate between the two groups. Researchers also found surprising results regarding the effectiveness of medicine in treating ADHD. In contrast to children in United States, youth in northern Finland are rarely treated with medicine for ADHD, yet the prevalence, symptoms, psychiatric comorbidity and cognition of the disorder is relatively the same as in the U.S., where stimulant medication is widely used. Although the medication is very effective in the short-term, the study raises questions concerning its long-term efficacy. The study also confirmed that hyperactivity and impulsivity decrease with age, while inattention increasingly predominates; that ADHD is associated with increased rates of other psychiatric problems, especially depression, anxiety, oppositional behaviors, conduct disorders, and post-traumatic stress disorder. The study of Finnish adolescents found a prevalence of 8.5% with a male/female ratio of 5.7:1.
McCRACKEN, J. T., VARILO, T., YANG, M. H., NELSON, S. F., PELTONEN, L., JÄRVELIN, M.-R., … HUMPHREY, L. A. (2007). Prevalence and Psychiatric Comorbidity of Attention-Deficit/Hyperactivity Disorder in an Adolescent Finnish Population. Journal of the American Academy of Child & Adolescent Psychiatry, 46(12), 1575-1583. Retrieved from http://www.sciencedirect.com/science/article/B987N-4XKP955-6/2/372aa973f494f5388341e5d4f371f00a
JÄRVELIN, M.-R., SMALLEY, S. L., LUBKE, G. H., MUTHÉN, B., MOILANEN, I. K., McGOUGH, J. J., … HURTIG, T. (2007). Subtypes Versus Severity Differences in Attention-Deficit/Hyperactivity Disorder in the Northern Finnish Birth Cohort. Journal of the American Academy of Child & Adolescent Psychiatry, 46(12), 1584-1593. Retrieved from http://www.sciencedirect.com/science/article/B987N-4XKP955-7/2/94c69b4fa20ac995cbdc3d4194643623
EBELING, H., JÄRVELIN, M.-R., SMALLEY, S. L., LOO, S. K., HUMPHREY, L. A., TAPIO, T., … TAANILA, A. (2007). Executive Functioning Among Finnish Adolescents With Attention-Deficit/Hyperactivity Disorder. Journal of the American Academy of Child & Adolescent Psychiatry, 46(12), 1594-1604. Retrieved from http://www.sciencedirect.com/science/article/B987N-4XKP955-8/2/c1eee1413cba1e3ee06dd25d24c9d770
HURTIG, T., EBELING, H., TAANILA, A., MIETTUNEN, J., SMALLEY, S. L., McGOUGH, J. J., … MOILANEN, I. K. (2007). ADHD Symptoms and Subtypes: Relationship Between Childhood and Adolescent Symptoms. Journal of the American Academy of Child & Adolescent Psychiatry, 46(12), 1605-1613. Retrieved from http://www.sciencedirect.com/science/article/B987N-4XKP955-9/2/9172d56334aa77d57da918211cc3e07b
http://www.eurekalert.org/pub_releases/2008-01/uoc--srq012208.php
Recent research found that thickening of brain areas that control attention in the right cortex (right orbitofrontal/inferior prefrontal and posterior parietal cortex ) was associated with better clinical outcomes in ADHD. A new study has found that these brain areas are thinnest in those who carry a particular variant of a gene. The version of the dopamine D4 receptor gene, called the 7-repeat variant, was found in nearly a quarter of youth with ADHD and about one-sixth of the healthy controls. Although this particular gene version increased risk for ADHD, it also made it more likely that the areas would thicken during adolescence, with consequent improvement in behaviour and performance.
Castellanos, X., Rapoport, J. L., Shaw, P., Gornick, M., Lerch, J., Addington, A., … Giedd, J. N. (2007). Polymorphisms of the Dopamine D4 Receptor, Clinical Outcome, and Cortical Structure in Attention-Deficit/Hyperactivity Disorder. Arch Gen Psychiatry, 64(8), 921-931. Retrieved from http://archpsyc.ama-assn.org/cgi/content/abstract/64/8/921
http://www.eurekalert.org/pub_releases/2007-08/niom-gpb080107.php
A long-running study of 678 families in upstate New York, surveyed children at 14, 16 and 22 years old (averages), and again when the children in the study had reached an average age of 33. At age 14, 225 (33.2%) of the teens reported that they watched three or more hours of television per day. Those who watched 1 or more hours of television per day at mean age 14 years were at higher risk of poor homework completion, negative attitudes toward school, poor grades, and long-term academic failure. Those who watched 3 or more hours of television per day were most likely to experience these outcomes, and moreover were at higher risk of subsequent attention problems and were the least likely to receive postsecondary education. Analysis of the data also indicated that television watching contributes to learning difficulties and not vice versa.
Johnson, J. G., Cohen, P., Kasen, S., & Brook, J. S. (2007). Extensive Television Viewing and the Development of Attention and Learning Difficulties During Adolescence. Arch Pediatr Adolesc Med, 161(5), 480-486. Retrieved from http://archpedi.ama-assn.org/cgi/content/abstract/161/5/480
http://www.eurekalert.org/pub_releases/2007-05/jaaj-ftv050307.php
A comparison of the effects of OROS methylphenidate (Concerta), a controlled-release stimulant, and extended release amphetamine salts (Adderall XR) on driving performance in teens with ADHD has found that treatments with Concerta led to fewer inattentive driving errors and less hyperactive or impulsive driving errors, such as speeding and inappropriate braking, compared with Adderall XR and placebo.
Cox, D. J., Merkel, L., Moore, M., Thorndike, F., Muller, C., & Kovatchev, B. (2006). Relative Benefits of Stimulant Therapy With OROS Methylphenidate Versus Mixed Amphetamine Salts Extended Release in Improving the Driving Performance of Adolescent Drivers With Attention-Deficit/Hyperactivity Disorder. Pediatrics, 118(3), e704-710 . Retrieved from http://pediatrics.aappublications.org/cgi/content/abstract/118/3/e704
http://www.sciencedaily.com/releases/2006/09/060905225503.htm
http://www.eurekalert.org/pub_releases/2006-09/uovh-rfn090506.php
A study of 172 children who were enrolled in a community-based study of low levels of lead exposure has found evidence that increasing lead exposure is linked to impairment on a number of executive functions (impaired in those with ADHD), but that certain genetic and biological factors seemed to predispose an individual to the negative effects of lead exposure. For instance, only children with certain variations of the DRD4 gene seemed vulnerable to lead's adverse effects on attentional flexibility. Boys were more vulnerable to this effect than girls.
The study was presented on May 1, 2006 at the annual Pediatric Academic Societies meeting in San Francisco.
http://www.eurekalert.org/pub_releases/2006-05/cchm-sla042606.php
Mixed amphetamine salts extended release (MAS XR) substantially improved the speed and accuracy in information processing of young adults with attention-deficit/hyperactivity disorder (ADHD). Excitingly, the improvement persisted after the 3 weeks of treatment had been stopped for 3 weeks.
Kay, G.G. & Kardiasmenos, K.S. 2006. Effect of Mixed Amphetamine Salts Extended Release on Neurocognitive Speed in Young Adults with ADHD. Paper presented at the annual American Psychiatric Association Meeting in Toronto, Canada. Poster #NR678
Kay, G.G. & Kardiasmenos, K.S. 2006. Effect of Mixed Amphetamine Salts Extended Release on Neurocognitive Accuracy in Young Adults with ADHD. Paper presented at the annual American Psychiatric Association Meeting in Toronto, Canada. Poster #NR679
http://www.eurekalert.org/pub_releases/2006-05/pn-mas_1052406.php
Previous research has suggested that the production of myelin (a fatty insulation coating the brain's internal wiring) is a key component of brain development through childhood and well into middle age, when development peaks and deterioration begins, and that midlife breakdown of myelin is implicated to onset of Alzheimer's disease later in life. Now new research suggests the disruption of myelination is a key neurobiological component behind childhood developmental disorders, such as autism and attention deficit/hyperactivity disorder, and addictive behaviors. The analysis also suggests that alcohol and other drugs of abuse have toxic effects on the myelination process in some adolescents.
Bartzokis, G. 2005. Adolescent Psychiatry. Hillsdale, N.J.: The Analytic Press Inc.
http://www.eurekalert.org/pub_releases/2005-11/uoc--bom111405.php
ADDERALL XR® significantly improved driving performance, cognitive function and attention in young adults with attention-deficit/hyperactivity disorder (ADHD) in a controlled driving simulator study. An earlier study found that adults with ADHD had a significant higher incidence of traffic violations, and license suspensions than patients without ADHD — ADHD patients were five times more likely than non-ADHD patients to have five or more speeding tickets and three times more likely to have had three or more vehicular crashes.
Kay, G. 2005. The Effect of Adderall XR and Atomoxetine on Simulated Driving Safety in Young Adults with ADHD. Presented at the 18th Annual U.S. Psychiatric & Mental Health Congress in Las Vegas, NV.
http://www.eurekalert.org/pub_releases/2005-11/pn-axs110805.php
A researcher that has previously demonstrated that working memory capacity can be increased through training, has now reported that the training software has produced significant improvement in children with ADHD — a disability that is associated with deficits in working memory. The study involved 53 children with ADHD, aged 7-12, who were not on medication for their disability. 44 of these met the criterion of more than 20 days of training. Half the participants were assigned to the working memory training program and the other half to a comparison program. 60% of those who underwent the wm training program no longer met the clinical criteria for ADHD after five weeks of training. The children were tested on visual-spatial memory, which has the strongest link to inattention and ADHD. Further research is needed to show that training improves ability on a wider range of tasks.
Klingberg, T., Fernell, E., Olesen, P. J., Johnson, M., Gustafsson, P., Dahlström, K., … Westerberg, H. (2005). Computerized Training of Working Memory in Children With ADHD-A Randomized, Controlled Trial. Journal of the American Academy of Child & Adolescent Psychiatry, 44(2), 177-186. Retrieved from http://www.sciencedirect.com/science/article/B987N-4XKH91F-B/2/44e91ac6d66cbd1822ee93ad0b14ec59
http://www.sciam.com/article.cfm?articleID=000560D5-7252-12B9-9A2C83414B7F0000&sc=I100322
Data from parents and teachers of 2000 randomly selected children has revealed that only 29% of children with attention problems finished high school compared to 89% of children without such problems. When it came to hyperactivity, the difference was smaller: 40% versus 77%. After taking account of factors such as socioeconomic status and health issues that are correlated with ADHD, inattention was still a highly significant contributor, but hyperactivity was not.
I’ve always been intrigued by neurofeedback training. But when it first raised its head, technology was far less sophisticated. Now a new study has used real-time functional Magnetic Resonance Imaging (fMRI) feedback from the rostrolateral prefrontal cortex to improve people's ability to control their thoughts and focus their attention.
A study involving 360 patients with degenerative dementia (109 people with dementia with Lewy bodies (DLB) and 251 with Alzheimer's) and 149 matched controls, has found that 48% of those with DLB had previously suffered from adult ADHD. This compares with 15% found in both the control group and the group with Alzheimer's. DLB tends to be under-diagnosed, but is thought to account for around 10% of dementia cases in older people.
ADHD and DLB are thought to both involve the same neurotransmitter pathway problems.
A twin study involving 457 pairs has found that ADHD on its own was associated with a reduced ability to inhibit responses to stimuli, while reading disabilities were associated independently with weaknesses on measures of phoneme awareness, verbal reasoning, and working memory. Both disorders were associated with a slow processing speed, and there was a significant genetic correlation between RD and ADHD.
A working memory training program developed to help children with ADHD has been tested by 52 students, aged 7 to 17. Between a quarter and a third of the children showed significant improvement in inattention, overall number of ADHD symptoms, initiation, planning/organization, and working memory, according to parental ratings. While teacher ratings were positive, they did not quite reach significance. It is worth noting that this improvement was maintained at the four-month follow-up.