Dr Amir-Hamayoun Javadi, School of Psychology, University of Kent

>>Today, I'm going to talk about memory, in particular long-term memory, and also how we can improve maintenance of memory and also generally improve memory.

>>To begin with, I would like to give you an example of an everyday action, so imagine you are sitting in your living room and watching your favourite TV show and you would like to make a cup of coffee.

>> You put that intention in your mind and then you get up and you find your way to the kitchen. At that point, you remember the procedure of making a cup of coffee and you need to find where different stuff are so for example you need to know where the cup is, where the spoon is, where the coffee is, where the water is. 

>> To begin with, for example, you boil the water and then you put enough coffee in your coffee maker. You put the boiling water in the coffee maker and then you wait long enough, not too short not too long, and then you put the coffee in your cup. 

>> And then, at that point, some people like plan to clean the coffee maker after, for example, watching their TV show and some people wash the coffee maker right away.

>> Now, imagine that you want to wash the coffee maker after your TV show so you put that intention in your mind as well and then you go back to your living room and you continue with your TV show.

>> As you have noticed, we had quite a few different types of memories that we had to put in our memory and also recall from our memory. The first one was the memory for the intention that we had. 

>> So, for example, if you go to the kitchen and you forget what your intention is you get to the kitchen and you don't remember that you wanted to make a cup of coffee. Or, you also put the intention of cleaning your coffee maker after the TV show so that is called prospective memory. 

>> There are also memories about space, so how to get to the kitchen or where the different things are so those are spatial memories that are important for navigation. 

>> We also have procedural memory: how you make coffee or even walking that's also some sort of procedural memory but that's very automatic. And finally, memories for magnitudes: how much coffee you would like or how long you would like to wait for your coffee to be prepared.

>> We generally have two types of memories: long-term memory and short-term memory. The focus of my talk today is long-term memory.

>> Long-term memory has generally two different categories. One of them is the creative memory - sometimes it is called explicit memory or conscious memory - this is a form of memory that you can generally verbalise. 

>> You can talk about it, this is stuff that you can think and you can memorise them very explicitly. So here I give you two examples. So one of them is events and the other ones are about facts. 

>> So, for example, what you did yesterday or what you did for your last birthday.

>> And about facts so for example what is the capital of a certain country. These are a form of explicit memory that you have in your mind and you can verbalise them. 

>> The other type of memory is non-declarative memory. Those are sometimes called implicit memory or unconscious memory. 

>> So, here again you see two of the examples like procedural memory: how to ride a bike or how or how to make a cup of coffee. And also conditioning. So you might have heard about Pavlovian conditioning: the bell, the dog, the food and the saliva. 

>> So it is some sort of conditioning that is some sort of implicit memory. Today I'm going to focus on declarative memory which is the form of long-term memory. In order to memorise something, we need to go through different stages.

>> The first part is the information. The information comes in to our mind through different sensory inputs, through different inputs, so for example if it is visual information it goes through our eyes. 

>> Or through our ears if it is auditory information or tactile information. So this information needs to be encoded to form memory that is some sort of learning as well and following encoding or learning at a later stage it is retrieval that you recall that piece of information. 

>> For example, you memorised something yesterday and you remember it today. But what is important here is what happens in between encoding and retrieval which is called consolidation. So for example, when you memorised something yesterday and you recall it today, in between memorisation and recall you were awake, you slept, you for example had some physical activities.

>> You might go to the gym for example. All these different activities are part of the consolidation and they have different effects on the maintenance of information. The main focus of my talk is consolidation. 

>> We have a lot of different functions and procedures happening during consolidation and here I'm going to give you three examples of those functions. These are generally the most important functions that happen during consolidation. 

>> The first one is item integration. That is the one that you integrate the new piece of information in your previously-stored information. So you already have a lot of information and when you learn something new, the new information is integrated with the information that you had before.

>> The other one is selective item consolidation and that's the one that among all the information that comes in and you select some of them and you ignore other ones. 

>> And finally, a multi-item generalisation. That is the one that you create an abstract idea of the information, you integrate the information together, you create some rules and I'm going to talk about it in a moment.

>> So, for item integration I'm going to show you some diagrams to make it easier to understand. Imagine you have the these four pieces of information already stored in your mind and then a new piece of information comes in: ABC. 

>> When these pieces of information go through consolidation, you will integrate them all together and you will have five pieces of information all stored in your mind, that is called integration. 

>> The other form of consolidation is selective item consolidation. Imagine you have two pieces of information coming in and then when they go through the consolidation one of the items will be maintained better than the other one. So you will consolidate ABC stronger than the other piece of information. 

>> Imagine you are walking the street and people pass by you and you see a dog, for example, barking at a man.

>> The next day, you might not remember the people who pass by you but you might remember that there was a dog which was barking at a man. So that is the piece of information that you kept in your mind, you highlighted in your mind. 

>> And the other pieces of information you ignore them. They are still there but they are not as highlighted. 

>> The other one is multi-item generalisation. So imagine you have five pieces of information coming in into your mind. Then these five pieces of information go through the consolidation. 

>> A lot of different stuff happens. So, the first one is you will store them in the memory. So you have a memory out of five pieces of information and also you create some new memories.

>> For example EFG. That is a false memory so that is technically a piece of memory that was not among the five pieces of memories that came into your mind but you created that extra piece of memory which is false memory.

>> The other one is you create a rule of the input that you have so if you pay attention all the letters are in sequence like ABC or DEF, so you have to create that rule in your mind and you anticipate that if somebody gives you for example L, the the next letters will be M and N and also you create a gist of the information so as you pay attention all the pieces of information come with a triplet of letters. 

>> So that is the gist that you create through the consolidation. So, how can we modulate consolidation? How can we improve the maintenance of memory? How can we enhance our memory? 

>> There are a lot of different methods and here I'm going to give four examples of different interventions, different actions and different methods that we use in the lab and also in everyday life that help with memory maintenance and also consolidation.

>> The first one is sleep, so when you sleep a lot of stuff happens in the brain and, for example, if you memorise something and then you sleep and after that you recall that information your memory performance is better as compared to you memorise something and then you just stay awake and then you recall that piece of information. 

>> So sleep helps a lot with memory improvement, memory maintenance and it has also been shown that even six minutes of sleep is enough to have a boost of memory performance.

>> But it's not like if you sleep for 12 minutes your memory performance will be two times better, the relationship is not linear. The other type of intervention is different methods of brain stimulation. 

>> In this image you see electrical brain stimulation. In this method we put one or more electrodes on the head of the participant and we pass very very weak electrical current in between the electrodes to modulate the activity of the nodes underneath the electrodes. 

>> This is a very safe and painless method, it's very friendly because the the current amplitude is very small. So participants might feel a slight tingling sensation but that is all. Using this method, we can improve cognition and we can modulate a behaviour quite effectively.

>> The other one is music. It has been shown that listening to music can help with memory maintenance and memory consolidation. And yet there are also a lot of questions yet to be answered. 

>> I'm going to talk about it in a moment about the questions that researchers are currently asking. The other one is physical exercise. Physical exercise is a very exciting and very powerful tool for
cognitive enhancement. 

>> Not only can it have the physiological effects on your body like physical well-being but also it can improve cognition a lot and also it has effects on mental wellbeing. 

>> We use all these tools and methods in in the School of Psychology and also in my lab to investigate how we can modulate cognition and in particular how can we improve cognition not only in healthy populations but also in patients and also in elderly populations. 

>> Imagine a participant comes into the lab and then they ask them to memorise a set of stimuli similar like this like apple or desk or ball. And we show them 80 of these images for example and we ask them to memorise them for later recall. 

>> And following the encoding phase we ask them to cycle for half an hour and then they have one hour of retention interval. That is, the whole cycling and the retention interval is the consolidation phase. 

>> And then, following that, we have the retrieval phase. During this phase, participants are asked to recognise the stimuli that they saw before. 

>> So we mix 18 new images with the images that they saw before and the participant's task is to recognise which ones they saw before and which ones are new ones. 

>> And in another session, participants come in, they memorise a new set of stimuli and instead of cycling they just have one hour and half retention interval. 

>> And following that they have the retrieval phase. The interesting result was that exercise improved memory performance significantly more than rest conditions. 

>> So what this shows is that even 30 minutes of physical exercise is enough for you to have an improved memory performance which is extremely exciting. 

>> Currently, researchers are investigating how they can optimise these methods. How can they have longer-lasting effects or stronger effect or which populations they can apply these methods to. 

>> So, for example, for the sleep research if you have time to sleep for 30 minutes is it better for you to sleep for 30 minutes like continuously or is it better to like break it down and have three 10 minutes of sleep over a different period of time? 

>> Or which aspect of memory is consolidated in which phase of sleep for example we have a declarative memory or non-declarative memory and they are consolidated in different phases of sleep. 

>> For brain stimulation, we have a lot of different protocols of brain stimulation and we still don't know which one is more effective or which one has a longer lasting effect. 

>> So for example is it better for you to have brain stimulation every day or is it better for you to have it every other day? It has also just recently been shown that if you make the stimulation last longer it might have a reverse effect. 

>> So there are a lot of unknowns in that field as well.

>> With music, one of the main questions is what is the relation between cognitive enhancement or generally changes in cognition and your favourite music.

>> So, for example, if your favourite type of music is hard rock or metal is it better for you to listen to the same music in order to have cognitive enhancements or is it better for you to listen to classical music to have cognitive enhancement?

>> So that is one of the questions that we are addressing right now in my lab. And finally, we have physical exercise. So for example one of the questions that we are investigating in the lab is that, which one is better?

>> To exercise for longer but with lower intensity or shorter with higher intensity? So we also want to investigate whether different physical fitness has any correlation with different protocols of physical exercise. 

>> There are also some other methods for changing consolidation and also there are other behaviours that we have everyday that change consolidation. So, for example, drinking coffee has been shown to have effect on consolidation it usually impairs consolidation. But it's not totally like that's not the end of the research. 

>> In my lab we use all these methods to investigate cognitive enhancement in particular and also memory and learning. We test healthy participants to investigate different cognitive aspects and different cognitive functions and also we use patients such as brain-damaged patients, stroke patients and we are now extending our research to the elderly to investigate how we can use these methods to improve their cognition.

>> To find out more, please visit my website at javadilab.com Thanks for listening.