Cognitive and physical training can help older adults with mild cognitive impairment (MCI) maintain or improve their ability to move and think simultaneously, but hearing ability and sex influence outcomes, according to a new Concordia-led study.
The researchers used data from the SYNERGIC clinical trial, a multi-institutional study of how exercise and brain training can improve cognition, mobility and falls in older adults. Their study followed 75 adults between the ages of 60 and 85 with mild cognitive impairment before and after a 20-week intervention involving physical training and cognitive exercises.
The researchers specifically looked at how hearing loss affected dual-task performance - walking while performing mental activities like counting backwards or naming animals. Hearing loss was self-reported and objectively assessed following a following a common test of hearing acuity.
The team found that poor hearing was strongly linked to worse dual-task performance. Participants with poor hearing were found to walk more slowly, have less stable gait and have more difficulty walking and carrying out cognitive tasks simultaneously.
The effects were even more pronounced in individuals who reported poor hearing and had lower cognitive performance. They scored worst on dual-task measures.
"We already know that males tend to get hearing loss earlier in life and it tends to be more severe than in females," says lead author Rachel Downey (PhD 25). "But this is the first documented study to demonstrate this relationship between hearing loss and dual-task performance in male participants."
"The study is especially novel because it looks at this within a sample of people with MCI," adds supervising author Karen Li, a professor in the Department of Psychology and director of the Laboratory for Adult Development and Cognitive Aging.
"Even for individuals in the pre-dementia stage - and not everyone who has MCI will progress to dementia - we see that the severity of cognitive impairment plays a role in their dual-task gait."
The study was published in the journal Frontiers in Aging Neuroscience.
Sex and hearing loss type shape key differences
The paper also demonstrates that targeted physical and computerized cognitive training can noticeably improve dual-task performance.
Participants completed one of the following interventions:
- exercise (aerobic and resistance-training) and a sham cognitive training (watching videos, performing simple Internet searches)
- both exercise and cognitive training
- a placebo (toning and stretching exercises with sham cognitive training).
"The intensity of the exercise increased every four weeks, so it was about more than just maintaining aerobic-resistance capacity," notes Berkley Petersen, co-author and PhD candidate.
After the 20-week intervention period, the researchers found that participants in the exercise and cognitive training group showed the greatest improvement in walking stability while performing cognitive tasks. The biggest improvement was found among males with higher levels of objective hearing loss.
However, among females, those with self-reported hearing loss showed the most improvement. The researchers note that while the relationship in males between self-reported and objective hearing loss was strong, it was weaker among females- suggesting that they may be more worried about hearing loss and over-reporting it, or vice versa.
Participants in the placebo group showed little to no improvements or exhibited declines in performance following the study period.
Declines and risks are treatable
"This study shows that even if an individual has poor hearing and poor cognitive performance, their brain is still plastic enough to benefit from this kind of training," Downey says.
"The risk of falling grows with aging. When you add on hearing loss and cognitive impairment, it gets even higher," Li says. "There are a lot of practical health care implications for this kind of work because it's all non-pharmacological and involves exercises that can be done at home."
Read the cited paper: "The effect of hearing ability on dual-task performance following multi-domain training in older adults with mild cognitive impairment: findings from the SYNERGIC trial"
