Navigation Links
New study reconciles conflicting data on mental aging

WASHINGTON A new look at tests of mental aging reveals a good news-bad news situation. The bad news is all mental abilities appear to decline with age, to varying degrees. The good news is the drops are not as steep as some research showed, according to a study published by the American Psychological Association.

"There is now convincing evidence that even vocabulary knowledge and what's called crystallized intelligence decline at older ages," said study author Timothy Salthouse, PhD.

Longitudinal test scores look good in part because repeat test-takers grow familiar with tests or testing strategies, said the University of Virginia psychologist. Factoring out these "practice effects" showed a truer picture of actual mental aging, according to Salthouse.

Still, the declines, although pervasive, are smaller than thought, according to the report in the July issue of Neuropsychology. That finding contradicts data gathered by the other major research approach to aging, cross-sectional studies, which compare the performance of different age groups at the same time.

With both methods subject to bias, "It remains important to recognize the limitations of each type of study design when interpreting results," Salthouse said.

To learn what really happens as people age, Salthouse tackled how different research methods have led to different findings. Cross-sectional studies that compared the abilities of younger and older adults showed big drops in key areas. Longitudinal studies suggested that, until about age 60, abilities are stable or even improve. Which type of study, if either, was right?

To find out, Salthouse analyzed data on five key cognitive abilities from the longitudinal Virginia Cognitive Aging Project. Scores were available for 1,616 adults age 18 to more than 80 on tests of reasoning, spatial visualization, episodic memory, perceptual speed and vocabulary. The data were collected over an average test-retest interval of two-and-a-half years.

First, Salthouse sorted participants into age brackets by decade, each with well more than 100 participants, except for the 80-89 bracket, with 87 participants. Second, he estimated the size of practice effects by comparing scores earned on the second test by the longitudinal participants with scores on a first test by another group of participants. He also used statistical methods to adjust for the chance that weaker performers dropped out between the first and second tests.

Practice effects were evident across the board, allowing test-takers to score higher the second time around not because they truly were more able, but because they knew the test an unavoidable byproduct of repeated testing. Although the numbers varied by ability and age, practice effects were found to be as large as or larger than the annual cross-sectional differences.

Numbers in hand, Salthouse removed the practice-related "bonus points." Stripping them out generated a new set of cognitive scores that could be expected to reflect more accurately normal mental aging in healthy adults.

With practice effects taken into account, the age trends in the longitudinal data became more similar to results from cross-sectional studies in the places where they had diverged. The different methods now agreed on the downward direction of change. However, the increments were smaller. In other words, the mental abilities of younger adults still rose over time, but not nearly as much. And the mental abilities of older adults still fell over time, but not quite as much.

Knowing how practice effects, selective attrition and actual maturation affect how people change over time will put psychologists in a better position "to evaluate true age changes, and how they might relate to late-life pathology and everyday functioning," Salthouse said.

Salthouse also found that practice effects played a bigger role in younger than older adults, possibly because younger people learn better. "Longitudinal comparisons in people of different ages may be even more complicated because the amount of longitudinal change may be partially determined by the individual's learning ability at a given age," he noted.


Contact: Public Affairs Office
American Psychological Association

Related medicine news :

1. Despite Treatment, Employees with Depression Generate Higher Absentee Costs, According to Thomson Reuters Study
2. American Council on Exercise (ACE) Study Reveals Kettlebells Provide Powerful Workout in Short Amount of Time
3. TV drama can be more persuasive than news program, study finds
4. Study carried out into biological risks of eating reptiles
5. Neuroimaging study may pave way for effective Alzheimers treatments
6. Study finds racial gaps continue in heart disease awareness
7. Luth Researchs IndicatorEDG(TM) Study Finds Americans Hopes of Achieving Their Dreams Are Fading
8. First blinded study of venous insufficiency prevalence in MS shows promising results
9. Soothing infants with food focus of childhood obesity study
10. People with anxiety disorder less able to regulate response to negative emotions, study shows
11. American Heart Association Rapid Access Journal Report: Study Finds Racial Gaps Continue in Heart Disease Awareness, Low Knowledge of Heart Attack Warning Signs Among Women
Post Your Comments:
(Date:11/26/2015)... ... November 26, 2015 , ... ... to discuss bioavailability and the need to integrate dose form selection in early ... with OBN, the membership organization supporting and bringing together the UK’s emerging life ...
(Date:11/26/2015)... Aliso Viejo, CA (PRWEB) , ... November 26, ... ... X users a new set of retro-fused, self-animating trailer titles with ProTrailer: Vintage. ... custom style options. These classically-influenced trailer titles work with any font, giving users ...
(Date:11/25/2015)... ... November 25, 2015 , ... As part of a ... ™ attracts volunteers together who want to combine talents and resources to help ... in the process. The non-profit launched its first major fundraiser on November 6, ...
(Date:11/25/2015)... MN (PRWEB) , ... November 25, 2015 , ... ... launched offering factory direct sauna parts and accessories. , Sauna accessories help ... of the bather’s style and personality. From basic styles for the purist looking ...
(Date:11/25/2015)... ... November 25, 2015 , ... For the first time, Vitalalert is donating ... Beat ” campaign. The partnership between the two groups began in 2014 with Vitalalert ... cause. , MAP International was founded in 1954 and is an international Christian-based health ...
Breaking Medicine News(10 mins):
(Date:11/26/2015)... November 26, 2015 Un nuevo ... Bremachlorin para el cáncer avanzado.   --> ... terapia fotodinámica de Bremachlorin para el cáncer avanzado. ... la inmunoterapia con la terapia fotodinámica de Bremachlorin para ... Research . --> Clinical Cancer Research . ...
(Date:11/26/2015)... , November 26, 2015 --> ... to use SyMRI to find optimal contrast weighting of MRI ... metastases, and has signed a research agreement with SyntheticMR in ... hospital. Using SyMRI, it is possible to generate multiple contrast ... after the patient has left, thus making it possible to ...
(Date:11/26/2015)... November 26, 2015 ... the "2016 Future Horizons and Growth ... Testing Market: Supplier Shares, Country Segment Forecasts, ... their offering. --> ) ... "2016 Future Horizons and Growth Strategies in ...
Breaking Medicine Technology: