Episode 25: Memory with Dr. Andrea Wilkinson

What is memory?

• Episodic memory = your memory for specific events that have taken place.

• Semantic memory = your memory for knowledge, concepts and facts.

• Procedural memory = your memory for how to do things.  

Memories help make you who you are.

Memory is the chain that connects your past to your present.

MEMORY = learning that has persisted over time. It is information that has been stored and, in many cases, can be recalled (retrieved for later use).

Memory isn’t an all or nothing thing. There was a case of a patient named H.M. who underwent surgery in 1953 to remove part of his hippocampus (the part of the brain responsible for learning). After the surgery, H.M had trouble forming new episodic memories (memories for events), but his procedural memory (his memory for how to do things) was still intact. So, after the surgery, H.M was not able to remember anyone new (even if he saw them every day for 20 years); but he did know the people he met and had relationships with before the surgery. He was also still able to learn new skills because his procedural memory wasn’t damaged.

This case study of HM’s taught the scientific community so much about memory. The biggest lesson was that we have different types of memory (e.g., memories for events – like what you had for lunch yesterday and memories for how to do things – like play the piano). These different types of memories are controlled by different parts of your brain.

All memories are not stored in one specific area of the brain. In fact, strong memories often include sights, sounds, smells, and emotions. So, important or emotionally powerful memories will link many different areas of the brain together.

In a neurodegenerative disease like dementia (e.g., Alzheimer’s) – episodic memories are impacted first and foremost. For example, someone might forget where they parked the car at the mall – but, they wont likely forget the lyrics to their favourite song. This is because our memory for music is stored in many different areas of the brain and it is also highly emotional.

Human memory involves the ability to both preserve and recover information that has been learned or experienced. Of note, this is not a flawless process. Sometimes people forget or misremember things. One reason for this may be that the to-be-remembered item has not been properly encoded into your memory in the first place.

How are Memories Formed?

In the late 1960s, psychologist Richard Atkinson and Richard Shiffrin talked about memory formation in three stages:

1. Encoding

2. Storage

3. Retrieval

According to this 3-stage memory model, memories first enter your brains as fleeting sensory input. So, if I asked you to remember the following words:

• Dog

• Watch

• Garden

You would likely repeat them to yourself in your mind over and over again until I asked you to repeat the words back to me.

This is how information is recalled for a brief amount of time (also known as “short-term memory”).

But, if you want to keep that list of words in your memory for even longer, you need to change the information into a usable form, which occurs through a process known as encoding. For example, you can create a vivid story and image in your mind about a dog wearing a watch in the garden. The more bizarre the image, the more likely it will be remembered for later use.

How Long do Memories Last?

Some memories are very brief, just seconds long, while other memories can endure much longer: days, weeks, months, decades or even a lifetime. Most of these long-term memories lie outside of your immediate conscious awareness, but – when you want or need the memory, you can bring them back to consciousness.

For healthy memories, there are lots of little tricks you can use to help you remember and these are call mnemonics (memory aids).

Three Memory Strategies

1.   Convert words into pictures.

According to research, we have better memory for pictures than for printed words (Foos & Goolkasian, 2010). This is called the picture superiority effect. It has been suggested that this occurs because you pay more focused conscious attention to pictures than to printed words. Think about it – you can layer so many additional details onto an image – as compared to a word. This effect has even been found in the oldest-old adults, who were 90 – 97 years old (Cherry et al, 2008).

Everyday Application: If you need to remember a list of things (e.g. grocery items), and you don’t have pencils and paper with you, try to imagine pictures of these items in your head!

2. Deeply encode what it is that you want to remember.

According to research, you have better memory for words studied using deep encoding as opposed to shallow encoding. Deep encoding occurs when words are processed by relating information to other knowledge, such as how useful an object might be on an uninhabited island.  Shallow encoding occurs when words are processed based on non-meaningful characteristics such as the number of vowels.

In shallow encoding, you pay little attention to meaning and only focus on physical characteristics. Therefore, you are unable to form strong memories of the to-be-remembered words. However, in deep encoding, a lot of attention is paid and focused on relating the word to something already known or to an imagined experience. By deeply encoding words, you are better able to remember them at retrieval.

Everyday Application: When trying to remember someone’s address create a meaningful story to prevent you from forgetting it – make sure you link it to something you already know! 

Example: If you want to remember 105 Bond Street, think of the ages of your grandchildren (10 and 5) and James Bond. You can also think of the importance of October 5/May 10 if they are special dates for you.

3. Create an environment that supports the formation of new memories

Research suggests that as you age, you become more susceptible to distractions in your environment. In particular, studies have demonstrated that memory performance is disrupted when attention has to be divided between two tasks.

Think about trying to remember information you are reading in a magazine when the news is on TV and your partner is asking you about dinner plans and your phone is ringing. Your attention is getting pulled in too many different directions, which makes coding memories more difficult.

So, in order to improve memory performance, it is important to ensure that there are minimal distractions present in the environment, and that your full attention is devoted to remembering a specific to-be-remembered piece of information.

Everyday application: Minimize distractions when trying to remember something (e.g., a phone number or a new friend’s name). For example, if you are having a conversation and there is a lot of commotion in the same area, you may want to relocate to a quieter location where you can really focus on the discussion with your friend.

Conclusion

 A lot of how much you remember depends on the time you take to learn the information in the first place, as well as how personally relevant or meaningful you make the to-be-remembered information.

Memory is extremely powerful. It is constantly shaping and re-shaping your brain and your life and your identity.

Do you remember the 3 words I asked you to remember? Imagine that ridiculous image you conjured up of the DOG, wearing a WATCH, sitting in the GARDEN.