Episodic memories are those that are vital to our ability to accurately retell stories. They are associated with autobiographical events, such as a past Christmas party or your first trip to a zoo.
Dr Chandramallika Basak, assistant professor at UT Dallas' Center for Vital Longevity (CVL), looked at the episodic memory in 46 adults aged bewtween 60 and 86.
They were studied at three different periods: before memory training, immediately after training and six weeks after completing the training.
The participants were separated into two groups - predictable training or unpredictable training. They did not differ in terms of education or cognitive abilities.
For both groups, sequences of digits in different colours were presented and participants were asked to indicate when the colour of the current digit matched an earlier one of the same colour.
In training that involved a predictable element, the changing colours occurred in a fixed order, while the colour switching was random for the unpredictable training.
"Completing the task when the color changes occur unpredictably requires more cognitive resources, or control," said Basak.
For Basak, the effect is similar to what happens when you travel home from work in a new way.
In that circumstance, cognitive demands required to find your way around increase with the new route's unpredictability.
The two groups of participants demonstrated equivalent story recall before training, but the group given training with the unpredictable element was able to narrate a previously heard story more accurately than the other group.
However, that benefit was not as apparent when the same group was tested six weeks later.
"This could be a case of use it or lose it - that the training must be sustained. Future research could investigate if booster training may help with retaining the long-term benefits," said Basak.
"Studies such as this one shed light on the role of cognitive control in memory training. They also highlight the differences in training-related performance gains between people, and could help researchers and clinicians develop better cognitive training strategies for older adults who are at risk for dementia."
The findings are published in the journal Frontiers in Psychology.
Throwing a few random components into memory training is more effective in enhancing episodic memory than training with predictable elements, according to new findings from UT Dallas researchers.