Visualising cause and effect relationships can be used as a memory strategy for older adults and people affected by amnesia, say scientists.

The researchers cite an example of how to avoid leaving home without an umbrella when it is likely to rain. The trick is, while listening to the weather forecast, to imagine an umbrella tip being lodged in your front door lock, so the door cannot be secured.

Lead scientist Dr Jennifer Ryan, from the Baycrest Centre for Geriatric Care in Toronto, Canada, said: "Previous research has shown that imagining two objects fusing into one will help people work around these memory deficits; but our work demonstrated that understanding the relationship between the two items is also important.

"We know that cognitive function is impaired during ageing and this strategy could be one workaround for minor memory problems, depending on what you need to achieve."

The approach, known as "unitisation" , involves three elements, "fusion", "motion" and "action/consequence".

For the study, each element was tested separately on 80 healthy individuals aged 61 to 88 who were each given a memory task.

The greatest memory improvements were seen in participants using only the action/consequence aspect of unitisation.

In the cited example, the "action" involved the umbrella being lodged in the door lock, and the "consequence" was not being able to lock the door.

Dr Ryan added: "We are trying to understand what's important to unitisation and what people need to learn in order to benefit. There is no single strategy that will fix your memory, but one method may be more be suitable than another."

The research is published in the journal Memory & Cognition.