Adolescence

Older news items (pre-2010) brought over from the old website

Aerobic fitness boosts IQ in teenage boys

Data from the 1.2 million Swedish men born between 1950 and 1976 who enlisted for mandatory military service at the age of 18 has revealed that on every measure of cognitive performance, average test scores increased according to aerobic fitness — but not muscle strength. The link was strongest for logical thinking and verbal comprehension, and the association was restricted to cardiovascular fitness. The results of the study also underline the importance of getting healthier between the ages of 15 and 18 while the brain is still changing — those who improved their cardiovascular health between 15 and 18 showed significantly greater intelligence scores than those who became less healthy over the same time period. Those who were fittest at 18 were also more likely to go to college. Although association doesn’t prove cause, the fact that the association was only with cardiovascular fitness and not strength supports a cardiovascular effect on brain function. Results from over 260,000 full-sibling pairs, over 3,000 sets of twins, and more than 1,400 sets of identical twins, also supports a causal relationship.

http://www.physorg.com/news179415275.html
http://www.telegraph.co.uk/science/science-news/6692474/Physical-health-leads-to-mental-health.html

Amphetamine use in adolescence may impair adult working memory

Rats exposed to high doses of amphetamines at an age that corresponds to the later years of human adolescence showed significant declines in working memory as adults, long after the exposure. The researchers tested two types of amphetamine exposure: intermittent (a steady dose every other day) and "binge-escalation," in which increasing amounts of the drug were given over a period of four days, followed by a simulated binge – a high dose every two hours for eight hours on the fifth day. The type of exposure did not make a significant difference.

Stanis, J.J. et al. 2009. Amphetamine-induced deficits in a working memory task are more significant in drug-exposed adolescent rats than drug-exposed adults. Presented October 21 at the annual meeting of the Society for Neuroscience in Chicago.

http://www.eurekalert.org/pub_releases/2009-10/uoia-aui101909.php

Linking education to future goals may boost grades more than helping with homework

A review of 50 studies looking at what kinds of parent involvement helps children's academic achievement has revealed that the most important thing parents can do for their middle school children (early adolescence) is relate academic achievement to future job goals, and give advice on specific study strategies. Parents' involvement in school events also had a positive effect, but a smaller one. Helping with homework had mixed results.

Hill, N.E. & Tyson, D.F. 2009. Parental Involvement in Middle School: A Meta-Analytic Assessment of the Strategies That Promote Achievement. Developmental Psychology, 45 (3), 740-763.

http://www.eurekalert.org/pub_releases/2009-05/apa-tet051909.php

Adolescent binge drinking may compromise white matter

An imaging study of 28 teens, of whom half had a history of binge drinking (but did not meet the criteria for alcohol abuse), has found that those who had engaged in binge drinking episodes had lower coherence of white matter fibers in 18 different areas across the brain. The findings add to a growing literature indicating that adolescent alcohol involvement is associated with specific brain characteristics. White matter integrity is essential to the efficient relay of information in the brain.

http://www.physorg.com/news159646086.html
http://www.eurekalert.org/pub_releases/2009-04/ace-abd041509.php

Childhood sleep problems persisting through adolescence may affect cognitive abilities

A longitudinal study involving 916 twins whose parents reported their children's sleep problems from age 4 until 16, of whom 568 completed tests of executive functioning at 17, indicates that those whose sleep problems persisted through adolescence had poorer executive functioning at age 17 than children whose problems decreased to a greater extent. Sleep problems as early as age 9, but particularly around age 13, showed significant associations with later executive functions. Some problems appear to be more important than others: changes in levels of 'sleeping more than other children' and 'being overtired' were most important, and nightmares and 'trouble sleeping' the least. However, a child's level of sleep problems early in life don’t appear to be an important factor.

http://www.eurekalert.org/pub_releases/2009-03/aaos-csp022709.php

From 12 years onward you learn differently

Behavioral studies have found eight-year-olds learn primarily from positive feedback, with negative feedback having little effect. Twelve-year-olds, however, are better able to process negative feedback, and use it to learn from their mistakes. Now brain imaging reveals that the brain regions responsible for cognitive control (specifically, the dorsolateral prefrontal cortex and superior parietal cortex, and the pre-supplementary motor area/anterior cingulate cortex) react strongly to positive feedback and scarcely respond at all to negative feedback in children of eight and nine, but the opposite is the case in children of 11 to 13 years, and also in adults.

van Duijvenvoorde, A.C.K. et al. 2008. Evaluating the Negative or Valuing the Positive? Neural Mechanisms Supporting Feedback-Based Learning across Development. The Journal of Neuroscience, 28, 9495-9503.

http://www.eurekalert.org/pub_releases/2008-09/lu-f1y092508.php
http://www.physorg.com/news141554842.html

Frequent TV viewing during adolescence linked with risk of attention and learning difficulties

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. Archives of Pediatrics & Adolescent Medicine, 161 (5), 480-486.

http://www.eurekalert.org/pub_releases/2007-05/jaaj-ftv050307.php

Prefrontal cortex loses neurons during adolescence

A rat study has found that adolescents lose neurons in the ventral prefrontal cortex in adolescence, with females losing about 13% more neurons than males. Human studies have found gradual reductions in the volume of gray matter in the prefrontal cortex from adolescence to adulthood, but this finding that neurons are actually dying is new, and indicates that the brain reorganizes in a very fundamental way in adolescence. The number of neurons in the dorsal prefrontal cortex didn’t change, although the number of glial cells increased there (while remaining stable in the ventral area). The finding could have implications for understanding disorders that often arise in late adolescence, such as schizophrenia and depression, and why addictions that start in adolescence are harder to overcome than those that begin in adulthood.

Markham, J.A., Morris, J.R. & Juraska, J.M. 2007. Neuron number decreases in the rat ventral, but not dorsal, medial prefrontal cortex between adolescence and adulthood. Neuroscience, 144 (3), 961-968.

http://www.sciencedaily.com/releases/2007/03/070314093257.htm

Brain still developing at age 18

In a study of 19 freshman college students, it’s been found that, anatomically, significant changes in brain structure continue after age 18. The changes were localized to regions of the brain known to integrate emotion and cognition — specifically, areas that take information from our current body state and apply it for use in navigating the world (right midcingulate, inferior anterior cingulate gyrus, right caudate head, right posterior insula, and bilateral claustrum).

Bennett, C.M. & Baird, A.A. 2006. Anatomical changes in the emerging adult brain: A voxel-based morphometry study. Human Brain Mapping, Article published online 29 Nov 2005 in advance of print./span>

http://www.eurekalert.org/pub_releases/2006-02/dc-bcs020606.php

Study links adolescent IQ/activity levels with risk of dementia

An analysis of high school records and yearbooks from the mid-1940s, and interviews with some 400 of these graduates, now in their 70s, and their family members, has found that those who were more active in high school and who had higher IQ scores, were less likely to have mild memory and thinking problems and dementia as older adults.

Fritsch, T., Smyth, K.A., McClendon, M.J., Ogrocki, P.K., Santillan, C., Larsen, J.D. & Strauss, M.E. 2005. Associations Between Dementia/Mild Cognitive Impairment and Cognitive Performance and Activity Levels in Youth. Journal of the American Geriatrics Society, 53(7), 1191.

http://www.eurekalert.org/pub_releases/2005-07/cwru-sla070105.php

Teen's ability to multi-task develops late in adolescence

A study involving adolescents between 9 and 20 years old has found that the ability to multi-task continues to develop through adolescence. The ability to use recall-guided action to remember single pieces of spatial information (such as looking at the location of a dot on a computer screen, then, after a delay, indicating where the dot had been) developed until ages 11 to 12, while the ability to remember multiple units of information in the correct sequence developed until ages 13 to 15. Tasks in which participants had to search for hidden items in a manner requiring a high level of multi-tasking and strategic thinking continued to develop until ages 16 to 17. "These findings have important implications for parents and teachers who might expect too much in the way of strategic or self-organized thinking, especially from older teenagers."

http://www.eurekalert.org/pub_releases/2005-05/sfri-tat051205.php

The best way to get teens to learn

A recent study has been investigating how to motivate teenagers to learn. Using obese and non-obese early adolescents and a text on health-related issues, researchers found that telling the teenagers that learning more about these issues and adopting a healthier lifestyle was important for their health (an intrinsic goal) was more effective than telling them that it would help them become more physically attractive and appealing (an extrinsic goal). They also found that trying to pressure the teens by using guilt-inducing language was less effective than a more autonomy-supportive approach that enabled them to experience their studying as more self-chosen and volitional.

Vansteenkiste, M., Simons, J., Lens, W., Soenens, B. & Matos, L. 2005. Examining The Impact Of Extrinsic Vs. Intrinsic Goal Framing And Internally Controlling Vs. Autonomy-Supportive Communication Style Upon Children's Achievement. Child Development, 76 (2), 483-501.

http://www.eurekalert.org/pub_releases/2005-03/sfri-tbw032105.php

Smoking associated with working memory impairment in adolescents

A study of 41 adolescent daily smokers and 32 nonsmokers has revealed that adolescent smokers had impairments in accuracy of working memory performance. Male adolescents as a group begin smoking at an earlier age than female smokers and were significantly more impaired during tests of selective and divided attention. All of the adolescent smokers also showed further disruption of working memory when they stopped smoking.

http://www.eurekalert.org/pub_releases/2005-02/yu-scc020105.php

Alcohol's damaging effects on adolescent brain function

A number of speakers at Symposium speakers at the June 2004 Research Society on Alcoholism meeting in Vancouver, reported on research concerning the vulnerability of the adolescent brain to the damaging effects of alcohol. Some of the findings presented were:

• The adolescent brain is more vulnerable than the adult brain to disruption from activities such as binge drinking. Adolescent rats that were exposed to binge drinking appear to have permanent damage in their adult brains.
• Subtle but important brain changes occur among adolescents with Alcohol Use Disorder, resulting in a decreased ability in problem solving, verbal and non-verbal retrieval, visuospatial skills, and working memory.
• The association between antisocial behavior during adolescence and alcoholism may be explained by abnormalities in the frontal limbic system, which appears to cause "blunted emotional reactivity".
• Alcohol-induced memory impairments, such as "blackouts", are particularly common among young drinkers and may be at least in part due to disrupted neural plasticity in the hippocampus, which is centrally involved in the formation of autobiographical memories.

http://www.eurekalert.org/pub_releases/2005-02/ace-ade020705.php

Changes in the brain during adolescence

A study of the post-mortem cerebral cortexes of six 12- to 17-year-olds and five 17- to 24-year-olds has revealed a number of physical differences between the adolescent and the adult brain. The average pyramidal soma size was 15.5 % smaller in the older age group, while a number of other measures (including cortical thickness and neural density) were slightly larger. These changes are thought to reflect certain cognitive changes that occur during adolescence - specifically, the increase in knowledge and understanding, and the decrease in the ability to acquire new sounds and speech patterns.

Courten-Myers, G.M. 2002. Paper presented at the American Academy of Neurology 54th Annual Meeting in Denver, Colorado, on April 19.

http://www.eurekalert.org/pub_releases/2002-04/aaon-bug040502.php