A new study has revealed that the ability of human brain to juggle between two tasks, such as walking and talking, begins to diminish almost a decade earlier than previously thought. The research has been conducted by scientists from Harvard Medical School and Hebrew SeniorLife. It says that the ability to dual-task starts declining by the age of 55, a decade before old age, as traditionally defined by the threshold of 65 years. Scientists said this struggle may be a warning sign of dementia.
"We assessed a large number of individuals between the ages of 40 and 64 years, and observed that the ability to walk under normal, quiet conditions remained relatively stable across this age range," lead researcher Junhong Zhou said in an article posted on the website of Harvard Medical School.
"However, even in this relatively healthy cohort, when we asked participants to walk and perform a mental arithmetic task at the same time, we were able to observe subtle yet important changes in gait starting in the middle of the sixth decade of life," the researcher further said.
The study has been published in The Lancet Healthy Longevity.
The researchers studied 640 people in Spain between May 2018 and July 2020 for the study.
"As compared to walking quietly, walking under dual-task conditions adds stress to the motor control system because the two tasks must compete for shared resources in the brain," said Zhou.
"What we believe is that the ability to handle this stress and adequately maintain performance in both tasks is a critical brain function that tends to be diminished in older age," the researcher added.
The authors added that it's important to note that while they observed that dual-task walking tended to diminish with advancing age across the entire cohort, not everyone in the study fit this description.