Study: Brains of Older Adults Less Adept at Switching Rapidly Between Tasks

Posted on April 17, 2011

Human brains are not built for multitasking. Your brain does not perform two tasks simultaneously. Instead, it switches rapidly from task to task. A new study has found that brains of older adults have a much more difficult time switching between tasks.

The study asked participants to view a nature scene for 14.4 seconds. In the middle of the experiment the participants were interrupted with the picture of a face and asked to guess the sex and age of the face. Then they were asked to recall the nature scene they were looking at before being interrupted by the face.

The study found that older people had more trouble recalling details of the nature scene.

As expected, older people had more difficulty maintaining the memory of the original image. The fMRI analysis revealed why. When the young and older adults were interrupted, their brains disengaged from a memory maintenance network and reallocated neural resources toward processing the interruption. However, the younger adults re-established connection with the memory maintenance network following the interruption and disengaged from the interrupting image. The older adults, on the other hand, failed both to disengage from the interruption and to reestablish the neural network associated with the disrupted memory

Wesley C. Clapp, PhD, a postdoctoral fellow in the Gazzaley lab and lead author of the study, said, "These results indicate that deficits in switching between functional brain networks underlie the impact of multitasking on working memory in older adults."

Adam Gazzaley, MD, PhD, UCSF associate professor of neurology, physiology and psychiatry, said, "The impact of distractions and interruptions reveals the fragility of working memory. This is an important fact to consider, given that we increasingly live in a more demanding, high-interference environment, with a dramatic increase in the accessibility and variety of electronic media and the devices that deliver them, many of which are portable."

Losing the ability to rapidly switch between tasks is crucial in the modern world where interruptions are common. Science Daily says Gazzaley's team is looking into whether brain training software could help older adults improve their mental task switching speed.

THE MIND