Memory
Memory is the process of encoding, storing, and retrieving information.
There are different types of memory which are all encoded and stored in different ways:
- events (things such as holidays, parties, or occasions)
- facts (such as what library means or what a tea bag is for)
- skills (such as riding a bike or tying shoelaces)
These different types of memory are important for different aspects of our lives. ‘Event’ memory allows us to remember important experiences and learn from them, ‘fact’ memory allows us to acquire and apply knowledge, and ‘skill’ memory allows us to perform complex tasks with ease and efficiency.
In addition, ‘working memory’ is what we use to store information for short periods, for example, when remembering the numbers we need to do a sum in our head.
Why do memory changes happen?
These different types of memory are supported by different networks within the brain. This means that the type of memory that is affected when someone is living with dementia depends to some degree on the type of dementia a person has and which areas of the brain are particularly affected.
For example, people living with the more common type of Alzheimer’s disease may experience changes and difficulties with their memory for events as an early symptom. Not being able to remember specific events or experiences is often the symptom which was the initial cause for concern and which led to the steps being taken towards a diagnosis. By contrast, for people living with posterior cortical atrophy (PCA), changes in memory may not occur until later in the disease timeline.
As the name suggests, people living with semantic variant PPA (svPPA) find that it is their memory for facts and meaning that is primarily affected. What words mean, or what the intended use of everyday items and objects is, becomes progressively more difficult to remember.
Memory losses associated with dementia are progressive, not just occasional. They may affect the ability to continue to work, or carry out familiar tasks, for instance having difficulty finding the way home. Eventually, and in combination with other thinking problems, memory problems may make familiar tasks, such as preparing a meal, increasingly difficult and at some point, impossible for someone living with dementia to be able to do on their own.
However it is also worth noting that because of ‘dementia and memory’ stereotypes, many thinking problems associated with dementia may be incorrectly labelled or dismissed as memory problems. For example, someone unable to identify themselves or a family member in a photo may be considered to ‘have forgotten that person and who they are’, when in fact they might be having visual problems (related to eyesight and/or brainsight issues) that prevent them from perceiving the face clearly, something that is common in PCA.
Memory for events
Memory for events is also known as episodic memory. This refers to our ability to remember specific events or experiences in our lives. These memories are often tied to specific times and places, and they include details about what happened, where it happened, and who was involved. Event memories are typically stored in the hippocampus, a region of the brain that is important for forming and retrieving memories. The hippocampus is often one of the brain structures affected earliest in Alzheimer’s disease, hence the common association between Alzheimer’s disease and problems remembering recent events and new information.
Examples of changes in memories for events
“Everyone forgets where they parked the car, or where they left their keys… but it was more than that. I couldn’t recall any of the prompts I needed to trigger my memory for where I had parked it, and had to ask for help from a passerby in order to contact my wife who came and collected me.”
“We had begun to wonder if Mum was struggling with her memory a bit, but put it down to the stage of life and various additional stresses she was carrying. It was noticing so many of the same item in her cupboards and refrigerator, many of which were out of date, that made us start to look in a bit more detail at the signs we had all been noticing.”
“I found all sorts of reasons not to attend various usual activities with family and friends. It was embarrassing not to be able to remember events they clearly expected me to, as well as struggle to follow the thread of conversations and events that were expected.”
Examples of changes in memories for events can include:
- forgetting:
- part or all of an event
- the details of a conversation, or that the conversation occurred at all
- whether a meal has been eaten, or details of what was eaten
- important dates such as birthdays, anniversaries or bill payment dates
- where family or friends live
- where the car is parked – to the extent that it is not possible to find it
- covering up for gaps in memory, for example by using additional lists, prompts and cues, or by creating excuses to divert attention away from instances which expose a lack of recall
- opting not to attend occasions where other people might be more likely to notice a memory problem
- buying surplus quantities of food, as the memory of previous grocery purchases becomes vague
- keeping, cooking and eating food which is out of date as an awareness of current date and time becomes more difficult
Memory for facts
Memory for facts is also known as semantic memory. It refers to our ability to remember factual information, such as the meaning of words, the use of objects, historical dates, or scientific concepts. Semantic memory helps us know that the black and white lines of a zebra crossing signify a safe place to cross the road, or to anticipate the aroma of a bouquet of roses. These factual memories tend to be acquired over time rather than being tied to a specific event, time, or place. Semantic memory includes information that lots of people know (e.g. what colour grass is) and specialist knowledge linked to individual hobbies and interests (e.g. a dog lover’s knowledge of the colour of chihuahuas or Weimaraners). Memories about facts rely critically upon the front of the temporal lobes of the brain. These are the areas affected earliest in people with semantic variant PPA (svPPA).
Examples of changes in factual memory
“My sister was a real stickler for road safety. We live next door to a school, and the ‘no parking’ safety zone extends around to our house. We knew that it was very out of character when she started parking on the yellow lines outside our drive.”
“Cooking remains a passion for my brother, and we are all so determined to support him in this activity for as long as we can. Our concerns were initially raised when we noticed raw foods being left uncovered in the kitchen, even during the height of hot summer days. And we also discovered bags of shopping that he had bought but not put away in the right place. So there was fresh food in the kitchen cupboard instead of the fridge, for example.”
“My wife used to be amazing at remembering the names of celebrities – it was a real talent of hers! We first noticed that something wasn’t quite right when she kept struggling to remember the names of really well known celebrities – she was getting so frustrated with this.”
Examples of changes in factual memory can include:
- loss of known information over time, such as historical or political information
- progressively forgetting words or names for objects, people and places
- saying ‘thingy’ or other vague terms to describe specific objects
- difficulty understanding word meanings or general knowledge
- difficulties with conversations and interactions with other people
- over time the person living with dementia may also forget what an object is used for. For example, forgetting the name for a can opener and then forgetting how to use the can opener
- finding it more difficult to do daily activities due to challenges interacting with usual objects, items and people
- buying, keeping, cooking and eating food which is not usual or which is out of date as the meaning and significance of food types, dates and times becomes less apparent
Memory for skills
Skill memory is also known as a procedural memory and refers to our ability to remember how to perform a task or activity, such as riding a bike, typing on a keyboard, or playing a musical instrument. These memories are often unconscious and automatic, and are often built across accumulated practice rather than being tied to specific events, times or places. Procedural memories are typically dependent upon the basal ganglia, a group of structures in the brain that are important for movement and motor control. Procedural memory tends to be most affected by conditions such as Parkinson’s disease dementia and frontotemporal dementia. The common tendency to think of memory as one ability can mean that people are surprised or confused by the preservation of procedural memory in conditions such as Alzheimer’s disease relative to profoundly impaired event memory (e.g. continued ability to produce the movements associated with a ballet routine learned decades earlier in response to the associated music).
Examples of changes in memories for skills
“Dad still gets out all the right tools for DIY job he’s trying to do but gets increasingly frustrated as he just doesn’t seem able to put them to use in the right order.”
“I know what ingredients are required to make our longstanding favourite meals, and with someone supporting me to get the sequencing right, can follow the steps that are needed. I couldn’t pull it together without help though – and I certainly don’t feel as safe using the oven or judging when things are cooked and ready.”
“She used to be a wonderful piano player, and used to teach others to play as well. She still loves to listen to piano music and watch other people play, but she really finds it difficult to play now. It used to be such an easy process for her.”
“I go to ‘walking football’ sessions these days. It’s good exercise and a nice group activity. My son finds it hard though because we used to play football and go to matches together – it was our thing. But now I can’t keep up with the speed of the game or follow the nuances of the rules. He finds this a sedentary second best. Belter than nothing – but not what we used to have together.”
Examples of changes in memories for skills can include:
- progressively finding it harder to perform everyday skills such as dressing and cooking, playing an instrument or using familiar technology
- having difficulty sequencing the steps required for accomplishing an activity. For example, struggling to follow the steps required to make a cup of tea, or put a meal together
- finding it harder to accomplish, and taking longer over activities that were previously ‘second nature’ or ‘automatic’
- finding it progressively harder to follow written or verbal instructions
- having increasing difficulty, or finding it impossible to learn new skills
Working memory
Working memory refers to the ability to retain information for immediate processing in order to accomplish complex tasks such as learning, reasoning, decision-making, and behaviour towards a particular goal. Working memory is also crucial for successful conversations, enabling us to hold in mind what is being said while we formulate our own responses and keep track of the ongoing dialogue. There are different types of this mental workspace, some specialised to handling sound-based information – like when we try to hold segments of a phone number someone has just told us in mind – and some tailored to visual and spatial information – like when we hold an image in mind whilst copying it down. Working memory tends to be affected early in the course of logopenic variant PPA (lvPPA) and Alzheimer’s disease, but can be impacted in a number of dementias owing to the widespread network of parietal, prefrontal and temporal brain areas involved.
Examples of changes in working memory
“I used to find it pretty easy to do calculations in my head. Now I need to write everything down, and even then, it can be a long and frustrating process to figure things out.”
“He can get pretty overwhelmed if there are too many things going on at once. We have learned to really slow things down and take it step by step so that it feels more manageable. For instance, we really enjoyed cooking together, and we have made some adjustments so that we can keep doing this, as long as I give him one task at a time to do. It’s much slower but it makes such a difference for him to be able to keep going.”
“Mum is so easily distracted. When we are together, I try to gently prompt her to help her start the activity that she is doing, like gardening or cleaning, and to move on to the next step if she gets a bit stuck. It’s hard to get the right balance of not taking over everything, but giving her enough support. We have also hired a cleaner to help out at home so it’s a bit less for her to worry about.”
Examples of changes in working memory can include:
- difficulty holding information (for example, a new phone number ) in mind
- difficulty following instructions, particularly those that involve multiple and/or complicated steps
- finding it difficult to organise and plan ahead
- starting tasks or activities and finding it difficult to finish due to distraction, loss of focus and/or difficulty moving to the next step
- losing the thread of conversation
Tips, strategies and adaptations for memory difficulties
- Try not to ‘test’ the person living with dementia on what they can recall, as this can lead to frustration and embarrassment if someone is having memory difficulties. This can take some adjustment, as we might be used to asking questions like ‘what did you do yesterday?’, which can be very challenging to answer.
- It can help to focus on being in the moment and doing shared activities together, which can also be used to prompt discussion.
- Use references to things that are happening in the present as anchors for conversation. For example, if a car pulls up nearby which is the model or colour of car that was previously driven, use that as a reference point for talking about memories of times spent driving that car and about journeys that were made in it, for example holidays or other significant trips.
- Make the most of common memory aids (a calendar or diary, calendar clock, shopping list, list of contact numbers or using a journal to help keep track of what has been done).
- Use skills which are maintained to help compensate for those which are becoming more difficult. For example, having a daily schedule written out on a large whiteboard, and an alarm set to signify relevant time points throughout the day.
- Leave prompts in places that will be helpful. For example, having the house keys in a safe place by the front door, or getting into the habit of putting a purse or wallet back into the bag which is usually carried, along with keys, a card to explain a diagnosis, emergency contact numbers etc. Please email the RDS Direct Support Team via contact@raredementiasupport.org to request a diagnosis specific information card.
- Other aids e.g. sticky notes, permanent reminders, a medication reminder box, colour codes for keys etc, electronic devices, smart devices, alarm clock, smartphones, computer/tablet reminders, apps (e.g. maps, life story work, relaxation exercises) and GPS locator devices can all be helpful.
- Using mental pictures, words or rhymes to help jog memory.
- Routines that are repeated every day can be a helpful way of triggering everyday activities.
- Plan events which are expected to be challenging at times of the day that suit the person living with dementia best.
- Try to avoid doing multiple activities at once, and minimise distractions as far as possible whilst engaged in activities which require attention and effort.
- Try to be consistent in the places where household items are kept, and put things away as soon as they are not being used.
- Try to arrange for someone to keep an eye on grocery supplies and ‘use by’ dates.
- Explore safer cooking options. Please see the adapting practically – home environment page for more information.
- Be mindful of the emotional and psychological impact of adapting to living with changes in memory and try to create opportunity for self-care. Please see the adapting emotionally page for more information.
- Simplify or adapt activities so that they rely less on the areas where someone is having difficulties and more on areas of strength e.g. music, creative activities, dance etc. Please see the engagement page for more information.
- Request a referral to an occupational therapist for support with appliances and memory aids.
- Speech and language therapists can advise on strategies to adapt to changes in communication abilities.