How does dementia affect long-term memory?
Unlike short-term memories from the preceding day or two, long-term memories are generally long-lasting, and cover anything from people’s earliest memories as children, through to their decades of life experience.
Whilst early stages of dementia account for short-term memory loss, over time, a person with dementia will experience long-term memory loss too.
Types of long-term memory loss
The three main types of long-term memories include:
These are about our motor skills and how we learn to do tasks that then become automatic to us, from walking and talking to riding a bike and swimming. Procedural memory forms part of our implicit memory, which is also known as our unconscious memory or automatic memory.
Memories of major life events and experiences related to them (such as where they happened, who you were with and how you felt) form part of your declarative memory, and are known as episodic memories. Examples include memories of getting married (and related memories of who attended and what you wore) – or memories of the day one of your children was born (and related memories about where your water broke or whether your child was born with a full head of hair).
Semantic memories also form part of your declarative memory and are related to understanding common knowledge and knowing the meaning of specific words and actions. For example, knowing the names of different colours, how letters sound and what basic words mean – like book, idea or laugh.
Dementia and long-term memory
Eventually a person with dementia will experience difficulties with their long-term memory, with procedural, episodic and semantic memories all affected. So, for example, they could experience difficulties with finding the right words to use as they speak, or their memories of family members or particular events may diminish or disappear altogether.
Significant memory loss can also make procedural memories fade, which is why people with dementia often find it difficult to do the tasks that they used to be able to do automatically. This can affect a person’s ability to complete Activities of Daily Living (ADLs) – in other words, common day-to-day tasks, such as brushing their teeth, showering or getting dressed. These ADLs may only be done part way or not at all, so, for example, a person with late-stage dementia could overlook their personal hygiene, wearing dirty clothes and forgetting to wash.
Memory loss can also affect judgement, so a person with dementia may not make the connection with it being cold outdoors and needing to wear long trousers or a coat.
How to delay long-term memory loss
Although conditions like Alzheimer’s disease can’t be reversed, there are things which can help slow the disease’s progression. Those with the condition could sustain their cognitive function and memory by increasing both their physical and mental activity (e.g. yoga, walking or doing Sudokus), as well as changing their diet.
There’s also a number of medications that can maintain or even improve brain function for a period of time.
Helpful ways to assist those with long-term memory loss
If a loved one is experiencing long-term memory loss, here’s 7 things you can do to help them:
- Introduce yourself by name each time you see them, to help put them at ease.
- Be patient, give them time and where necessary, prompts, to help them remember people, activities or events.
- Gently offer clear, step-by-step directions to help them complete ADLs like brushing their teeth or taking a bath.
- Maintain a routine so that they perform their ADLs at the same time each day – and use this routine to give their day purpose with small things to accomplish.
- Put up photographs of their family and friends where they live – and include captions, explaining who they are and where the photo was taken.
- Show them video footage of any moments in their life that have been recorded.
- Support them positively to lead full and happy lives, rather that reminding them regularly about their memory loss.
Words: Ash Anand