Why does our ability to remember things change with age?

As we age, our ability to remember changes. Most of us can’t remember anything about being a toddler, a phenomenon known as infantile amnesia.

We don’t know what causes this, but it could be that the circuits holding those memories are overwritten when new brain cells are born and integrated. Alternatively, the memories might still be there, just not easily accessible.

Around the time of adolescence, our prefrontal cortex—which controls things such as planning, decision making and working memory—becomes much more developed. As a result, we become better at remembering to do things in the future, and we can process more background information when deciding between different options.

Our ability to remember new information peaks when we are in our 20s, but it isn’t until we are in our 50s or 60s that it gets noticeably worse. Memory decline occurs as the connections between neurons naturally start to decay, and the links between brain regions become frayed. Dementia, experienced by one in 10 people over the age of 65, occurs when abnormal proteins accumulate inside and around neurons, killing the synapses and ultimately the neurons that hold memories together.

The role of exercise – QBI research at a glance

Exercise isn’t just good for your heart, it’s good for your brain too. QBI Research Fellow Dr Daniel Blackmore, in Professor Perry Bartlett’s laboratory, has shown that in aged mice, certain factors circulating in the blood are elevated after exercise. These factors enhance new neuron creation in the hippocampus, causing mice that have exercised to perform better in tests of spatial memory.

To test how exercise might improve memory and cognition in people, QBI has teamed up with researchers in UQ’s School of Human Movement Studies. Healthy 65–85 year-old adults will undertake a 12-month exercise regime while researchers measure structural changes in the hippocampus, and cognitive performance.

The aim is to identify how much and what exercise improves brain function in the elderly.

“If we can identify how exercise benefits brain health, we can optimise both lifestyle and pharmacological interventions to help people keep their brain healthy during aging,” says Dr
Mia Schaumberg, a postdoctoral researcher with QBI and the School of Human Movement Studies.

For more information visit: qbi.uq.edu.au/exercisestudy