Declining intelligence in old age linked to visual processing

August 4, 2014, Cell Press

Researchers have uncovered one of the basic processes that may help to explain why some people's thinking skills decline in old age. Age-related declines in intelligence are strongly related to declines on a very simple task of visual perception speed, the researchers report in the Cell Press journal Current Biology on August 4.

The evidence comes from experiments in which researchers showed 600 healthy older people very brief flashes of one of two shapes on a screen and measured the time it took each of them to reliably tell one from the other. Participants repeated the test at ages 70, 73, and 76. The longitudinal study is among the first to test the hypothesis that the changes they observed in the measure known as "inspection time" might be related to changes in intelligence in old age.

"The results suggest that the brain's ability to make correct decisions based on brief visual impressions limits the efficiency of more complex mental functions," says Stuart Ritchie of the University of Edinburgh. "As this basic ability declines with age, so too does intelligence. The typical person who has better-preserved complex thinking skills in older age tends to be someone who can accumulate information quickly from a fleeting glance."

Previous studies had shown that smarter people, as measured by standard IQ tests, tend to be better at discerning the difference between two briefly presented shapes, the researchers explain. But before now no one had looked to see how those two measures might change over time as people grow older. The findings were rather unexpected.

"What surprised us was the strength of the relation between the declines," Ritchie says. "Because inspection time and the intelligence tests are so very different from one another, we wouldn't have expected their declines to be so strongly connected."

The results provide evidence that the slowing of simple, visual decision-making processes might be part of what underlies declines in the complex decision making that we recognize as general . The results might also find practical use given the simplicity of the inspection time measure, Ritchie says, noting that the test can be taken very simply on a computer and has been used with children, adults, and even patients with dementia or other medical disorders.

"Since the declines are so strongly related, it might be easier under some circumstances to use inspection time to chart a participant's cognitive decline than it would be to sit them down and give them a full, complicated battery of IQ tests," he says.

Explore further: Stronger early reading skills predict higher intelligence later

More information: Paper: Current Biology, Ritchie et al.: "A strong link between speed of visual discrimination and cognitive ageing."

Related Stories

Stronger early reading skills predict higher intelligence later

July 24, 2014
A new study of identical twins has found that early reading skill might positively affect later intellectual abilities. The study, in the journal Child Development, was conducted by researchers at the University of Edinburgh ...

Older adults nearly twice as likely to have memories affected by distractions

July 14, 2014
Older people are nearly twice as likely as their younger counterparts to have their memory and cognitive processes impaired by environmental distractions (such as irrelevant speech or written words presented along with target ...

Motivation explains disconnect between testing and real-life functioning for seniors

July 28, 2014
A psychology researcher at North Carolina State University is proposing a new theory to explain why older adults show declining cognitive ability with age, but don't necessarily show declines in the workplace or daily life. ...

Socialization relative strength in fragile X longitudinal study

July 29, 2014
Standard scores measuring "adaptive behavior" in boys with fragile X syndrome tend to decline during childhood and adolescence, the largest longitudinal study of the inherited disorder to date has found.

Older is wiser, at least economically

September 24, 2013
The brains of older people are slowing but experience more than makes up for the decline, a University of California, Riverside assistant professor of management and several colleagues found when asking the participants a ...

Well-connected brains make you smarter in older age

May 23, 2012
Brains that maintain healthy nerve connections as we age help keep us sharp in later life, new research funded by the charity Age UK has found.

Recommended for you

Hospice patients define the changing nature of wisdom in their final days

January 24, 2018
Wisdom is typically considered to be the fruit of a long life, the accumulation of experiences lived and lessons learned. In recent years, scientists have created a consensus definition of wisdom as a complex trait with several ...

Short-course treatment for combat-related PTSD offers expedited path to recovery

January 23, 2018
Symptoms of Post-Traumatic Stress Disorder (PTSD) can be debilitating and standard treatment can take months, often leaving those affected unable to work or care for their families. But, a new study demonstrated that many ...

Social and emotional skills linked to better student learning

January 23, 2018
Students with well-developed and adaptive social and emotional behaviours are most likely to excel in school, according to UNSW researchers in educational psychology.

Priming can negate stressful aspects of negative sporting environments, study finds

January 23, 2018
The scene is ubiquitous in sports: A coach yells at players, creating an environment where winning is the sole focus and mistakes are punished. New research from the University of Kansas shows that when participants find ...

Study of learning and memory problems in OCD helps young people unlock potential at school

January 22, 2018
Adolescents with obsessive-compulsive disorder (OCD) have widespread learning and memory problems, according to research published today. The findings have already been used to assist adolescents with OCD obtain the help ...

People with prosthetic arms less affected by common illusion

January 22, 2018
People with prosthetic arms or hands do not experience the "size-weight illusion" as strongly as other people, new research shows.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.