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
Most experiments on memory and aging recruit younger adults (~18-22 years) from the university population and older adults (65+ years) from the general public. However, the reasons these individuals take part in psychology research seems to vary with age. For example, younger adults often take part in research studies because they are “reimbursed” with course credit, while older adults often seem to take part out of interest, in order to contribute, and/or to get an idea of their own cognitive performance. Further, research suggests that older adults are often more motivated to take part in psychology experiments than their younger counterparts. While greater motivation is usually seen as a good thing, it can make older participants susceptible to a phenomenon known as “stereotype-threat”. Stereotype-threat is worry related to confirming a negative stereotype about one’s group (e.g., all older adults have poor memory), which in turn actually gets in the way of doing the task. In a recent paper (Ryan & Campbell, in press), we argue that this task-related worry may disrupt older adults’ performance in typical lab settings and make it seem like memory declines more with age than it actually does. By designing studies that minimize the prevalence of stereotype threat, we can paint a clearer picture of the true neurocognitive changes that occur as we age.
Visual working memory is the ability to briefly hold visual information, like pictures and objects, in memory. For instance, say you were tasked with watching a whole class of kindergarten children during outdoor play. If you are watching kids on the climber, and then turn your attention to another teacher for a moment, and then look back at the climber, visual working memory allows you to keep in mind where each kid should be on the climber. Recent work suggests that visual working memory can be flexibly divided, in that we can prioritize remembering some things over others. In our climber example, if you know that some kids are more likely to misbehave, you may pay more attention to them and remember where they were when you look away. This flexibility relies on our ability to select what to pay attention to and what to ignore. Since these attentional control abilities tend to decline with age, we might expect the flexibility of working memory to also decline with age, but this has yet to be tested. Thus, the goal of this study was to examine age differences in the flexibility of working memory. Young and older (65+ years) adults viewed four coloured squares that needed to be held in memory. Participants saw cues showing how likely they were to be tested on the colour of each square. Sometimes, only the cued squares needed to be remembered, but other times, participants had to flexibly divide their attention and prioritize some squares over others (like the misbehaving kids above). We found that older adults were less able to flexibly divide their attention than younger adults, and tended to put greater emphasis on the highly prioritized square (i.e., the “naughty” kid in the bunch). Going forward, we plan to test whether this reflects the different strategies used by older and younger adults, or just a difference in how attention works with age.
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.
To date, our understanding of how age affects the mind and brain is largely based on tightly controlled, though largely artificial, experimental tasks or, on the other hand, the completely uncontrolled resting state (Campbell & Schacter, 2016). But do these effects extrapolate to everyday life?
One way to approximate everyday life in the scanner is to use movies, which are arguably more similar to our experiences in everyday life than standard experimental stimuli. We scanned a large population-representative sample while they watched Alfred Hitchcock’s “Bang! You’re Dead” and found that neural synchrony, or the correlation between different people’s fMRI timecourses, decreases with age (Campbell et al., 2015). Older adults (particularly those with lessened attentional control) responded to the movie in a more idiosyncratic fashion than both younger adults and their age-matched peers, suggesting that our experience of events in everyday life become more individualistic as we age
The brain is thought to become less specialized with age. However, this view is largely based on findings of increased frontal activation during cognitive tasks which fail to separate task demands (e.g., attention, decision making) from the cognitive process under examination (e.g., language comprehension).
We recently used a novel systems-level approach to show that these compensatory activations may simply reflect age differences in response to the task itself (Campbell et al., 2016). Participants were scanned using fMRI during two versions of an experiment: a natural listening version in which they simply listened to spoken sentences and an explicit task version in which they decided if the sentences were grammatical. We found that while task-free language comprehension only activates the auditory and language networks (which do not differ with age), performing a simple task with the same sentences recruits additional domain-general networks. These findings challenge the conventional approach to neurocognitive aging by showing that the neural underpinnings of a given cognitive function depend on how you test it.
A prominent theory of cognitive aging suggests that older adults are less able to form new associations and this leads to poorer memory performance. Our work has challenged this view, suggesting that rather than a deficit in the binding process itself, older adults have difficulty limiting their attention to target information and this leads them to form more irrelevant associations.
Using multiple converging methods, we showed that older adults’ lessened control leads them to form associations between overlapping targets and distractors (Campbell, Hasher, & Thomas, 2010), learn statistical regularities contained entirely within distracting information, which younger adults do not learn (Campbell, Zimerman, Healey, Lee, & Hasher, 2012), and form wider associations over time when learning a list of words (Campbell, Trelle, & Hasher, 2014). While this “hyper-binding” may lead to greater interference on standard tests of associative memory (Biss, Campbell, & Hasher, 2012), it may also put older adults at an advantage when knowledge of real-world relationships is put to the test.