 Thank you very much for being here to listen to all this information about the CLSA. My role in the CLSA, as Praminder mentioned, is that I'm the site principal investigator at the Ottawa site, and I'm also the lead for the psychological health working group, which includes the cognitive data. So that is what I will be talking to you about here today. I'll talk to you a bit about what the cognitive data even are, and give you a couple of examples of some of the work that's been published using these data, and then go on to talk to you a about the follow-up studies, what the current research that we're engaging in, or analyses of the data. So I'd like to thank everyone for their, we received, I received many questions about the cognitive data. The majority of the questions relating to people had a lot of questions about cognitive impairment and dementia, and concerns about their memory and cognitive functions. So I will do my best to answer those questions for you as I go through the presentation. So let's start, let me just, let's start by just telling you what I mean by the cognitive data. So I'm sure that those of you who are participants are very familiar with the, with these tests that I'm going to talk to you about quickly. So everyone, there's a subset of tests that everybody in the CLSA does, irrespective of whether you're in the tracking or the comprehensive cohort. And then we have some tests that we do only with the comprehensive cohort, just because we need people to be present with there are some that have materials that we, we need to do in person and do over the telephone. So everybody does the animal fluency test you'll remember this one where you are asked to name all the animals that you can think of in one minute. And in the comprehensive cohort we also do that test but using letters so to name all the items that you can think of in one minute with starting with a given letter. Everyone does the mental alternation test so that's the one where you're switching between numbers and letters one a to be etc. So those tests are assessing what we call your executive function so these, this is sort of like your, your brain's control center that you are managing your resources and paying attention and so on. So, also for executive function people in the comprehensive cohort do a task called the stroke task. So that is the one where you're asked to name. colors and you see color words and then you see color words printed in a different color ink and you have to name the color of the ink so this is testing the ability to inhibit irrelevant information and and name the color of the ink rather than reading the word. So we also so that's executive function we also have some tasks looking at memory function. So in both both cohorts people do the auditory verbal learning test where you're given a word list you're asked to remember it immediately and then at a five minute delay. And also the prospect of memory test so this is testing your ability to remember to remember. So, in real life that looks something like oh I need to remember that I have to buy some milk on my way home from work or something along those lines so in the way that we do the CLSA is by looking at whether so that's the test where you have to remember at some point during the testing session to take the money out of the envelope and give it to the examiner. And you, you are either asked to do it at a certain time or with a cube. And then finally we measure processing speed so that's the one with the computer screen where you're pressing your responding to items and we're looking at how quickly you're able to do that. So these are the cognitive data that we collect and we also ask people so since follow up one we started asking people questions about their self perceived memory function. So those are questions like, have you noticed any changes in your memory. Are you worried about those changes, and I'll talk a little bit about about that some work we've done using those data in a few slides. I'll do some examples now I'll first I'd like to say why we collect these data so I know people don't I hear that people don't like cognitive testing I've done lots of cognitive testing myself and I also don't like it so I certainly understand that and very much appreciate the efforts to do these tasks that they do not do not enjoy doing so why do we do this well first that allows us to track changes in people's cognitive function over time. And we can look at the, the effects of different events or different health conditions on cognitive performance. So I'll give you an example of that in a moment. There are five factors that might help people maintain cognitive function, and we can also track the progress of people who are worried if they're losing memory function, even if their memory testing is normal so there is. There are people who will report yes my memory. I feel like my memory is declining. And then when we look at their memory performance. Actually, they are, they look fine so this is a really interesting question of what does that mean for somebody to have the self reported concern about their memory or cognitive function in the in the context of normal cognitive performance. So, I'm going to highlight now a couple of there's many studies using the cognitive data I certainly don't have time to talk about all of them. I wanted to highlight a couple of studies that have been done using these data so this one that I'm going to talk about now about traumatic brain injury is some work done by my former PhD student Mark Bedard so he he based his PhD work on brain injury data, and he was interested in traumatic brain injury and cognition. So traumatic brain injury is when somebody suffers a head injury that result in injury to the brain and often people will refer to a concussion which is a TBI. So, in CLSA we asked people if they have experienced TBI is in the past. And what he wanted to do was look at performance and cognitive testing and people who've had a head injury, both initially and then after three years so in his thesis he was familiar from the, from baseline and from follow up one. And so, some people who experience a TBI experience also loss of consciousness. Some do not so he was also looking at that as a factor to assess the severity of the TBI. So he wanted to look at their cognitive performance and he was also interested in the role of social support as a predictor of preserve cognitive function so there have been some studies suggesting that social support is very valuable in terms of preserving cognitive function. It's quite unique to be able to do this kind of study with such a large group of participants and see if social support can help people maintain their cognitive function in the face of a challenge like a TBI. So, what he found was that people with a previous TBI at some point in the past, who had experienced a loss of consciousness with that TBI had lower cognitive performance and greater cognitive decline. And this is even years after the TBI so within CLSA we ask about lifetime traumatic brain injury it doesn't have to be recent. So, this is as expected the brain injury will have impacts on people's cognitive function. What was really exciting about this, his findings was that when he asked people about their perceived social support that it suggests that he found that perceived social support can help buffer against this cognitive decline so what that means is, if somebody reports that they have high levels of social support, they show less decline over the course of these three years compared to people reporting lower levels of social support and this is there's different types of social support so CLSA asks about different, different subsets of social support. And what he found was that specifically or particularly emotional support seemed to help buffer against cognitive decline. This is really exciting because it suggests avenues for helping people preserve their cognitive function, even in the face of challenges like a traumatic brain injury. So, and I mentioned previously, subjective cognitive status so we know that there are some people that report that they're worried about changes in their memory or cognition, even though their performance on cognitive tasks is normal. And we'll notice and we ask if you've noticed changes, and we also ask if you're worried about them so a lot of people that over 50% of people report that they have noticed changes which is understandable I would say that I feel like I've noticed changes in my cognitive function in the past few years my memory is not as high as it was when I was 25, but critically we also ask people if they are concerned about about those changes so when we're talking about people who have what we call subjective cognitive what we mean is people who say they are concerned they say their their memory has changed they say that they're concerned about it, and then when we test them their performance on cognitive tasks is normal. So of course people whose cognition is declining or who have cognitive impairment also often report that they're concerned about about their cognitive about their memory performance but here we're focusing on the people who don't show any signs of cognitive impairment. So, a critical question in research is what does this mean is it that the person is starting to decline, but the changes are too subtle, and are not detectable yet with with neuro psychological testing, or it could be that the person is fine and they're just experiencing anxiety or concerns, but so this we would call that the worried well. And so, typically when you look at people with subjective cognitive decline. There's a subset who are the worried well, and there's a subset who are what we would say in a stage where the patient knows but the doctor doesn't know yet that there's something wrong. So, we, one of the major goals and research is to figure out who of those people are on a trajectory to start experiencing cognitive impairment and who are not. We've started asking people as I said, in the second wave of data collection about their self perceived cognitive function so we can start to answer these questions. So, this is another more work done by a PhD student here at who was here at University of Ottawa at the time she was doing this work. And the question was that she was trying to identify the bio cycle social factors that predict these concerns about cognition. So, why do we want to do this well understanding the factors that predict concerns about cognition could help us design interventions to assist people with these with these concerns. What she found was that physical factors surprisingly physical factors such as low levels of physical activity, hypertension problems with vision did not predict concerns about cognition, but really what was driving these effects were as cycle, psycho social variables. So depression perceived perceived support and personality traits so for example people who are more extroverted are less likely to have concerns people who are more emotionally stable or less likely to have concerns, people who are very conscientious this is again, the risk of concerns. So, why, why is this important well when we when you're thinking about conceptualizing subjective cognitive concerns, it is really important to consider psychological and social factors so this can be relevant both in terms of building theory about what it means to have a CD or subjective cognitive decline, and also from a kind of clinical perspective when you're assessing someone determining how to how to think about their self reported memory concerns. So, what we're doing now is I, we're trying to identify factors that influence the risk of subsequent decline and people with these subjective cognitive concerns, and also examining factors like perhaps social support that might protect against cognitive decline so this really actually addresses a lot of the questions that I received about what is it that we can do to help us I'm concerned people say I'm concerned about my memory. Is there anything I can do to prevent myself from or reduce my risk of developing cognitive impairment so these are some of the questions that we're trying to answer now. We were, we were limited in our ability to really study dementia in the early years of CLSA because people at baseline when they entered the study everybody was cognitively intact so what that means is that as the study progresses, we are going to see some of our participants developing cognitive impairment and dementia and now really is when we're starting to be able to do more research looking at that population. So, there's this just a couple a little flavor of some of the work that's been done so far with the the cognitive measures. And we have lots of other at ongoing work so in collaboration with my colleague Megan O'Connell at the University of Saskatoon. She's developed a method to detect changes in cognition using the CLSA battery so she's developed something that we refer to as the cognitive impairment indicator, which uses the scores that we have available from the cognitive testing to identify people who might be at risk of having cognitive impairment. So this is important because you know, sometimes somebody will get a low score you can interpret a single low score as indicating cognitive impairment so I'm sure you all know this from having done. Lots of lots of cognitive testing sometimes you just, there's a test that you don't do well on for, for whatever reason maybe you're distracted or your brain kind of freezes and you don't for example produce very many items when you're asked to name all the animals that you can. And actually, all the other neuropsych scores or the cognitive scores look fine so this is what we would call a spurious low score. So using this cognitive impairment indicator allows, allows us not only to identify cognitive impairment within CLSA but also identify baseline like how many people show these types of spurious scores which can be very helpful for for clinicians when they're when they're working with clients in the clinic. And we can also use so a recent study that was just published. What was looking at shift work as so this is using this cognitive impairment indicator and identified that shift work is a risk factor for people exhibiting or being at risk for cognitive impairment so this is. There's a lot of huge possibilities of all of the factors that we can consider as potential risks for cognitive impairment and this work is is just beginning so this is a paper that came out in just in 2023, showing risks of shift work which of course disrupts sleep and circadian rhythm so it's not good for cognition. Another really important piece of work that we've done as part of the cognitive group with Megan and others is developing norms based on this very large sample so what do I mean by norms well this is where. When you are seeing a clinician and they do cognitive testing on you they need to know what a normal score would look like or what they would expect your score to look like, based on factors like age, education level, sex, and so on so we they will use norms to do that to determine if somebody looks like they're outside of normal limits on performance on a cognitive test, but oftentimes that the number of participants used to develop these norms is a little bit low so. This, the CLSA provides a really exciting opportunity to develop very robust norms based on this very large sample and so this is because we know that cognition is expected to change as we age there are some areas of cognition where you'll see changes to normal aging. So we're trying to determine when people's cognitive performance changes, if this is normal aging or if there's a cause for concern. And excitingly the norms are available in both English and French because many people complete their, their CLSA visits in French so this is really useful for clinicians across Canada. We are also looking to identify markers of cognitive decline and this will in the future will allow us to identify risk and protective factors for dementia. And we're also doing work so Tina mentioned the international nature of work with CLSA so we recently published harmonizing so there are lots of studies in other countries with large scale studies with older adults and we harmonized across those studies to determine the optimal way to ask people so this was related to the questions on subjective cognitive status to identify the optimal way to ask people about their cognitive function so because there's lots of different ways that you can do this. Like you, how's your function compared to other people your age compared to yourself 10 years ago, are you concerned about it, etc. So we've been able to use all of these data sets to to combine and figure out how those questions should best be posed. So, in conclusion, the cognitive data, crucial component of the CLSA we're so grateful that you complete these tests. They allow us to understand the factors, driving cognitive health throughout the lifespan. This can help us assist people in maintaining cognitive health and also identify people who are at risk of cognitive decline. And our ultimate goal is to lead to better quality of life for Canadians and others as well, of course. So, that's my final slides. Thank you very much for your participation and also for coming here today.