Memory for events (like what you did yesterday or that time you fell out of the canoe) is referred to as ‘episodic memory’. Episodic memory tends to decline with age, but it remains unclear what is causing this decline. Some work suggests that age-related differences in episodic memory may be due to a reduced ability to form new associations or link the different parts of a memory together (e.g., remembering that the canoe incident happened at your friend’s cottage and not your own). In the brain, these associations rely on regions of the medial temporal lobe (such as the hippocampus), but also the frontal lobes which control where attention is directed. Although age-related declines in associative memory have been linked to grey matter volume loss in these brain regions, results from previous studies have been mixed, possibly because they focused on a limited set of regions. In this study, we evaluated the relationship between grey matter volume within substructures of the medial temporal and frontal lobes and differences in associative memory performance across the adult lifespan.
We used data from over 300 individuals uniformly spread across the adult lifespan (18-87 years) from the Cambridge Centre for Ageing and Neuroscience (Cam-CAN; www.cam-can.org). Our results indicated that age was associated with reduced grey matter volume in the medial temporal and frontal lobes, and similar age differences were observed in both men and women. Memory performance also declined with age, but these declines were more pronounced in men. We also found that the structures of the frontal lobes alone predicted memory performance better than either the medial temporal lobe alone or both lobes combined. These findings suggest that age differences in associative memory are due to grey matter loss in the frontal lobes and, as a result, a reduced ability to control attention. So if you want to remember something, it’s best to minimize distraction so you can really focus your attention.
The ability to temporarily keep visual information in mind, known as visual short-term memory, is critical to many daily activities. Unfortunately, visual short-term memory declines throughout the adult lifespan. To get a better understanding of why visual short-term memory declines with age, we examined connectivity between brain regions during a memory task. Adults aged 23 to 86 years old, had to remember the direction of motion of one, two, or three clouds of colored dots. After a short interval, they had to report the direction that corresponded to a color cue. Brain activity during this task was measured with MRI.
We found that with increasing age, memory for motion direction declined, especially when more items needed to be memorized. With an increasing number of items, connectivity between brain areas increased, especially in areas involved in attention and visual perception. In older adults, this increase in connectivity happened to a lesser extent across the brain. Finally, an exploratory analysis suggested that better performance on the task is related to greater connectivity in attention regions in people of all ages, though this needs to be replicated in another study.
Our results confirm that brain regions involved in attention are essential for visual short-term memory across the adult lifespan. They also show a widespread negative impact of age on brain connectivity. Older adults showed a smaller change in connectivity as they needed to remember more items, possibly because remembering a single direction of motion is already challenging enough.
Working memory is the ability to temporarily hold information in memory, such as names and objects. Working memory can also be used to filter out information you may not want to focus on currently. For example, let’s say you are looking for your keys in your bag. While looking for your keys, you want to focus on features of your keys that will improve your chances of finding them, such as their shape and size. At the same time, you want to ignore irrelevant features, like other objects in your bag. Unfortunately, the ability to filter out irrelevant information declines with age.
In our study, we examined how different types of cues affect age differences in working memory performance. Across two experiments, younger and older adults were presented with two or four rectangles to remember. Before these items appeared, participants were told which colour they would be tested on (i.e., a positive cue telling them which colour to pay attention to) or which colour they would not be tested on (i.e., a negative cue telling them which colour to ignore). On some trials, they were given no hint at all. We found that while younger adults’ working memory was more accurate than that of older adults, everyone did better when given a hint about which colour would be tested. Both groups benefited more from positive than negative cues, suggesting that attention may become slightly “stuck” on negatively cued information before moving on to things that should be remembered. This may be particularly problematic for older adults, who sometimes have trouble redirecting their attention.
Since late 2019, news outlets and social media platforms have shown examples of people in need amidst the COVID-19 pandemic. Immunocompromised people who are scared to leave their homes. Service staff out of work due to restaurant closures. These stories seem designed, at least in part, to increase our concern for those in need and to make us want to help. But do they work? Is it enough to simply hear about the plight of others or do we also need to engage with these stories before they affect our willingness to help?
In a recent paper (published in the Journal of Applied Research in Memory and Cognition), we tested whether imagining helping a person in need increases one’s willingness to help more than just passively reading the same story, and whether this extends to unfamiliar (at the time) COVID-related scenarios. Across 3 large-scale, online experiments run between April-November 2020, we had older and younger adults read stories depicting people in need (e.g., This person is in quarantine and unable to take their pet to the vet). They then either imagined helping the person in need or engaged in a control task. We found that imagining helping others increases one’s self-reported willingness to help, in both everyday and COVID-related scenarios. This was quite surprising, as people did not have similar experiences upon which to draw for the COVID-related scenarios. Further, we found that imagining helping increases one’s concern for the person in need and one’s ability to picture the scene, which in turn related to a greater willingness to help. If you can picture yourself doing something, it seems more feasible. Taken together, these findings suggest that if we want people to help (e.g., comply with public health directives or donate more to charity), we should first ask them to imagine themselves helping. Seeing (in the mind’s eye) is believing.
When people remember what happened in the past, you might notice that they describe the events in chunks. For example, yesterday morning I ate breakfast, walked to school,started working, and so on. People tend to describe the past in this manner because our brains break our daily experiences into smaller events, so that the events can be easily stored in long-term memory. As a result, if a person wants to remember one specific detail from an event, they only need to remember that single event, rather than all their past experiences together. Imagine searching for information in an encyclopedia when you know what chapter to look in, compared to when you do not. This task would be much harder in the second situation!
In this study (published in Memory), we set out to determine whether older adults, like young adults, organize their long-term memories by storing them as individual events. We thought that if older adults organized their long-term memory differently from young adults, then it could explain why older adults often remember less detailed memories. To test this, we had younger and older adults read a series of short stories. Later, we used sentences from the stories to cue participants so that they could tell us what happened next. By looking at when people remembered sentences that came next and when they forgot them, we were able to measure how the different events from the stories were stored in memory. We found that both younger and older adults stored the events as single events in long-term memory. These results mean that even though older adults often remember the past in less detail, it is not due to changes in the way they organize those events in their memory system. We hope that future research will find different ways to explore why memory for past events changes with age, but it is a good sign that we did not find age differences here. A well-organized long-term memory is a helpful long-term memory!
Memory is important for many tasks in our everyday lives, from remembering our shopping lists to telling stories with family and friends. Some memories, like shopping lists, take effort to remember, while others seem to pop into our heads spontaneously without any effort at all, like a sign on the street reminding you to pick something up at the store. Although these memories differ in how they are brought to mind, their content can be very similar. Importantly, while growing older has been linked to declining effortful memory, spontaneous memory seems to be maintained with age. In this study, we measured brain activity during spontaneous and effortful memory retrieval to better understand how aging alters the way we access these different types of memories. Older and younger adults learned pairs of sounds and pictures. We then recorded their brain activity as they heard the sounds again and either spontaneously or effortfully imagined the pictures that had been paired with each one. We found that younger adults showed less brain activity in areas linked to effortful control when they spontaneously remembered the pictures, and more activity when they effortfully tried to remember them. However, older adults showed similarly high activity in these control areas during both effortful and spontaneous retrieval. This suggests that older adults may use these control areas to support memory retrieval even when they are not actively trying to remember something.
When people watch the same movie, their brains behave in a similar way, with the same parts activating at the same times. This similarity is important because people who respond similarly to others tend to have better memory for the movie. We have previously shown that as we age, our brains become more unique, and our response to things like movies become individualistic. In this study, we tested whether the uniqueness of aging brains during movie watching is caused by older adults simply looking at different parts of a movie than young adults. Older and younger adults watched a movie while their eye movements were tracked, then they had a memory test. Our results showed that both groups looked at similar things throughout the movie, suggesting that older adults’ unique brain activity is not caused by where they look, but possibly a lifetime of experiences that changes how we think. We also found that people who looked at the same places as everyone else tended to remember more from the film than people who looked at different places. On average, people attend to the most captivating things on screen. If you are someone whose attention wanders, you are probably missing out on something important
Have you ever forgotten the name of someone you just met? Although it can be embarrassing to have memory mishaps, the experience of forgetting the relationship between two unique items is common and becomes more frequent with age. It may seem like this is caused by some sort of memory failure, but research suggests that it may actually be caused by a problem with attention.
In an experiment from our lab, older and younger adults saw a series of object-word pairs. Some of the time, they were asked to ignore the word to make a judgment about the picture (distraction condition), and other times they were asked to pay attention to both items (full attention condition). In a subsequent test that probed unconscious memory, older adults seemed to remember the pairs from both conditions, despite being asked to ignore the words in the distraction condition. In contrast, younger adults only showed memory for pairs from the full attention condition. In everyday life, memory for distracting information can be helpful if that information becomes important later. The downfall is that having all this information in mind can sometimes make it difficult to remember what we want to remember, such as someone’s name.