The human brain’s ability to juggle between two tasks begins to say no almost a decade sooner than expected, a recent study finds.

Walking is generally done together with other activities like reading a signboard or talking to a friend. Nonetheless, a recent study by Harvard Medical School and Hebrew SeniorLife found the flexibility to dual-task starts to say no by the age of 55, a decade before old age.

The study evaluated 996 adults between May 2018 and July 2020 to know the connection between age, dual-task gait and cognitive function in middle age (between 40 and 64 years). 

“We assessed a lot of individuals between the ages of 40 and 64 years and observed that the flexibility to walk under normal, quiet conditions remained relatively stable across this age range,” lead researcher Junhong Zhou said in the study published in Lancet Health Longevity.

“Nonetheless, even on this relatively healthy cohort, after we asked participants to walk and perform a mental arithmetic task at the identical time, we were in a position to observe subtle yet essential changes in gait starting in the midst of the sixth decade of life,” Zhou added.

The researchers found the diminishing ability to dual-task was attributable to changes within the underlying brain function and never changes in physical function. Individuals with the declined ability are at a greater risk of falls and injuries, the study warns.

The decline within the brain’s ability to perform two tasks at a time shows a decline in age-related brain function, which can indicate an increased risk of developing dementia later in life.

“As in comparison with walking quietly, walking under dual-task conditions adds stress to the motor control system since the two tasks must compete for shared resources within the brain,” Zhou said. “Our study is essential since it has discovered that changes in this sort of brain resilience occur much sooner than previously believed…We hope our study will spur future research to find lifestyle and other modifiable aspects that support the upkeep of dual-task performance into old age, in addition to interventions that focus on these aspects.” 

Researchers also observed that although dual-tasking ability tends to diminish with advancing age, not everyone within the study suits this description.