PDF Summary:Remember, by Lisa Genova

Have you ever struggled to remember someone’s name at a party or forgotten where you parked your car? Are you worried that a memory lapse is a sign of Alzheimer’s? In Remember, neuroscientist and novelist Lisa Genova explores the complexity of human memory: She explains how memories are formed in the brain, what factors influence memory, and how understanding the science behind memory can help us better navigate both remembering and forgetting in our daily lives. She also reassures us that many types of forgetting are perfectly normal and even beneficial for cognitive function.

In our guide, we’ll first explore the types of memory, then we’ll discuss how memories are formed and how memory sometimes fails us. We’ll also discuss the impact of stress on memories, and we’ll provide some tips for how to improve your memory—as well as how to forget. In our commentary, we’ll add other theories and research to supplement Genova’s ideas, as well as tips for how to apply her advice.

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Finally, memories can also be distorted during retrieval, says Genova. As mentioned earlier, every time we retrieve a memory, we’re not playing back a recording but rather reconstructing the event. This reconstruction process often involves filling in gaps, reinterpreting details, and incorporating new information or perspectives. When we store the memory again after recall, we save this altered version, canceling out the original. This process means that frequently recalled memories, such as stories we tell often, can become increasingly distant from what actually occurred.

Memory “Sins” and Constructive Memory Theory

The unreliability of memory is well-established in psychology. Author and psychologist Daniel Schacter identified seven “sins” of memory, or specific ways in which memory can fail. The first of these seven are related to omission and include transience (our memories become weaker as we age), absent-mindedness (attentional lapses and minor forgetting), and blocking or tip-of-the-tongue syndrome (which we’ll discuss later in the guide).

The other four memory sins are related to commission and include suggestibility (the tendency of our memories to change or distort in response to things like leading questions or lies), bias (implicit beliefs or knowledge that can distort our memories), persistence (being unable to forget something you want to forget, like a traumatic experience), and misattribution (thinking you’ve seen or heard something that you didn’t).

And while memory distortions and failures may seem like major flaws, constructive memory theory argues that they’re actually adaptive—they evolved for a functional purpose to aid our survival. According to this theory, one of the main functions of memory is to help us plan for future events, and because the future doesn’t perfectly repeat what’s happened before, our memories adapted to flexibly alter our memories to better simulate and predict potential future occurrences.

Why We Need to Forget

While normal memory loss can be frustrating, it also serves an important purpose. If we remembered everything in perfect detail, our brains would become crowded with information, making reasoning and remembering difficult. Genova challenges the common perception of forgetting as a passive, default process that only happens to us involuntarily. Instead, she presents forgetting as an active, purposeful, and often beneficial process. Forgetting routine details like what we ate for lunch yesterday or how much traffic we drove through this morning actually helps us function more effectively by clearing mental space for new, relevant information.

(Shortform note: In addition to freeing up brain space, experts note another adaptive explanation for why we forget so much: We didn’t evolve to remember the world, but rather to understand it. While memory serves a vital function in our cognitive processing, remembering isn’t the brain’s primary goal; instead, the goal is to experience the world in the moment and use it to plan future actions. So a memory that won’t enhance our understanding of the world or help us make decisions about what to do next will likely be quickly forgotten.)

Both remembering and forgetting can be deliberate or accidental, and both are impacted by various factors. Next, we’ll explore stress’s influence on memory.

How Stress Impacts Memory

According to Genova, the activation of our stress response can affect our memory in different ways. When we’re stressed, the brain releases stress hormones into our bloodstream. This acute stress response was important for our ancestors to avoid dangerous situations, and it remains necessary for our daily functioning today. Genova explains that modern psychological stress affects us similarly to the physical threats our ancestors faced—the reaction an ancient human would have to being chased by a bear is the same reaction a modern human would have to committing a major social faux pas, for example.

Acute stress has a complex relationship with memory. It enhances the formation of memories related to the stressful situation by increasing attention and activating neurochemical processes that promote memory consolidation. However, this enhancement is selective, focusing on major details of the stressful situation while potentially impairing memory for peripheral details. For example, if you’re hiking in the woods and you encounter a bear, you might remember a lot about the bear’s appearance and behavior (as this is the major source of your stress), but little to nothing about details unrelated to the stressor such as the surrounding landscape.

Additionally, acute stress can interfere with retrieving memories, explaining why you may learn some information thoroughly while stressed but then be unable to remember it later.

Acute Stress and Executive Functioning

Memory is only one of the functions impacted by acute stress. Stress can influence multiple aspects of processing, particularly those related to executive function. This includes working memory, inhibition (the ability to control automatic responses in favor of responses relevant to the stressor), and cognitive flexibility (the ability to shift between different modes of thinking).

The theory Genova describes—that stress biases us to attend mostly to information related to the stressor we’re facing—is the most prevalent theory on how stress impacts executive functions. Research into this theory suggests that acute stress tends to impair working memory and cognitive flexibility, but that it actually improves inhibition (which includes selective attention—in this case, the ability to attend to the details related to the stressor rather than irrelevant information). Thus it may be more accurate to say that acute stress enhances attention rather than memory in general.

However, some research shows that acute stress can impair all three of these executive functions. To account for this, scientists have formulated another theory: that acute stress shifts your cognitive processing from top-down processes (and executive functions are considered top-down processes) to bottom-up processes. When using top-down processing, the brain takes its existing knowledge and uses it to interpret incoming sensory information. In contrast, bottom-up processing focuses on the incoming sensory information first, leaving higher-level cognitive processes (like relating it to existing knowledge) for later. This may help us focus on stressors in the moment without being distracted by preconceived biases.

Genova emphasizes that chronic stress, unlike acute stress, is uniformly detrimental to memory. Persistent stress continuously exposes us to stress hormones, which can desensitize our body’s stress response system and keep it permanently activated. This chronic activation inhibits the prefrontal cortex’s thinking abilities and can actually cause hippocampal neurons to die, and since the hippocampus is responsible for consolidation as mentioned earlier, this reduces our capacity to form new memories.

(Shortform note: Research suggests that the chronic stress associated with the Covid-19 pandemic may have impacted many people’s memories. While the viral infection itself is known to impact memory, experts note that even those who weren’t infected faced chronic stressors like social isolation. This stress increased people’s stress hormone levels, leading to widespread memory issues for people across the world. Studies showed a particularly severe impact on prospective and working memory.)

Managing stress is one way you can keep your memory healthy; in the next section, we’ll discuss this, as well as other tips for improving your memory.

How to Improve Memory

Genova offers many tips for how to improve your memory. One of the most important is to pay attention to what’s important to you, since we can only remember what we pay attention to (as explained earlier). This requires a conscious effort, as our default state is one of inattentiveness. She recommends making a concerted effort to focus on things you want to remember—such as joyful experiences or semantic information you think you’ll need later—and avoiding multitasking as well as minimizing the distractions in your life, such as devices and social media.

(Shortform note: To combat your natural state of inattentiveness, you may want to try engaging in hyperfocus—deliberately focusing on a single task for a specific period of time—when trying to pay attention to what you want to remember. In Hyperfocus, Chris Bailey provides the following steps for how to hyperfocus: 1) Choose when and how long you want to hyperfocus, 2) choose what you want to hyperfocus on, 3) limit and manage the distractions you may face, 4) use mindfulness and meditation to stay in the present moment, and 5) maintain your focus by preventing your mind from wandering.)

Managing Stress

Genova explains that managing stress well is an important part of maintaining a healthy memory. While we can’t eliminate stress from our lives, we can influence how we respond to it. The author recommends practices like meditation, yoga, exercise, mindfulness, and gratitude to reduce chronic stress’s negative effects. She specifically notes that regular meditation and exercise can increase hippocampal size. She also recommends you get plenty of sleep—at least seven hours per night—as sleep is important for the consolidation stage of memory formation. Finally, she advises against stressing about normal forgetting, as anxiety about memory lapses can create a self-fulfilling prophecy of increased forgetfulness.

(Shortform note: One reason mindfulness practices like meditation may reduce stress and improve your memory is because they can help you better identify and accept your emotions, and as mentioned earlier, emotion helps us identify what’s important to remember. This is further supported by research showing that suppressing emotions impairs memory—if you force your brain to ignore its emotional responses, you’re essentially communicating to it that nothing is important to remember. The importance of sleep may also be related to emotion, as studies show that sleep plays a critical role in the ability to regulate your emotions.)

Avoiding Memory Decay

As we’ve learned, memories can also decay over time even after they’ve been stored. To combat this, Genova recommends two main strategies: repetition and adding meaning. Repetition or rehearsal can make memories extremely durable, especially when done to a point that seems excessive. Adding meaning to information by connecting it to personal narratives or existing knowledge helps preserve memories as well.

(Shortform note: While Genova encourages repetition to the point of overlearning, other experts caution against it: In A Mind for Numbers, Barbara Oakley suggests that overlearning may become tedious, increasing emotional stress and making learning less efficient. Additionally, Oakley provides some tips on making information more meaningful, including turning it into a story. In Wired for Story, Lisa Cron explains why: Stories appeal to us neurologically because they helped us remember important information related to our survival during ancient times—so if you want to remember something, try turning it into a story.)

Remembering What’s on the Tip of Your Tongue

Genova also gives some specific advice on how to deal with moments when you know you have a piece of information stored in your memory, such as a word or a name, but you can’t quite seem to call it to mind—when it’s just on the tip of your tongue. Despite what many assume, using the internet to look up words that are on the tip of your tongue doesn’t weaken memory, and suffering through such states doesn’t strengthen it. To better remember names, she suggests creating elaborate associations, such as linking abstract names to concrete visual images or making meaningful connections.

For example, if your favorite book is the war novel Catch-22 but you keep forgetting the author’s name (Joseph Heller), you can think of the common phrase “War is Hell” to remember “Heller.” This similarity between the content of the book and the phrase about war will add meaning to the author’s name that makes it stick better in your memory.

(Shortform note: While using the internet to look up words during tip-of-the-tongue states may not weaken your memory overall, doing so casually may prevent you from storing that information for retrieval again later. Experts point to the “Google effect,” a phenomenon in which memory retrieval is poorer for information that’s easily accessible through external means. So you may look up a word that’s on the tip of your tongue and immediately resolve your tip-of-the-tongue state, but you may find yourself in the same state the next time you try to remember that same word. You can combat this by paying close attention to the information and making an effort to commit it to memory rather than looking it up and immediately discarding it.)

Improving Prospective Memory

When it comes to improving your prospective memory, Genova recommends techniques like using to-do lists and calendars. Additionally, being specific about plans (what exactly you intend to do and when) and using visual cues in impossible-to-miss locations (like placing needed items in a spot where you know you’ll see them) can significantly improve success. Also, take note of any changes to your routine, as these can interfere with the cues you normally use to remember to do things. Try to identify things that your usual daily activities remind you to do, and if your routine is altered, come up with something else to remind you to do those things.

For example, if you have a pet hamster that you feed each morning when you eat lunch, but then one day you skip your lunch, you might also forget to feed your hamster as you miss your usual memory cue. Rather than hoping or assuming you’ll remember to do it anyway, set a reminder on your phone or put a note on your computer screen to ensure you don’t forget.

(Shortform note: Other ways to improve your prospective memory include saying things out loud or telling someone else what you plan to do, linking the memory to a goal, and thinking through what you planned to remember while showering or doing other automatic activities. You can also take advantage of the role emotion plays in memory by attaching a strong emotion to the thing you’re trying to remember to do so it will feel more meaningful. If you struggle with prospective memory due to a brain injury, you may also want to consider therapy focused on prospective memory intervention.)

Preventing Alzheimer’s

Genova explains that most Alzheimer’s cases are the result of our genes combined with our lifestyles. Because of this, there are many things you can do to avoid developing Alzheimer’s disease. Some of these we’ve already covered, such as managing stress and getting enough sleep. Exercise—especially aerobic exercise—is also a major factor in preventing Alzheimer’s, as is mental stimulation (specifically, stimulation from learning new things, not necessarily brain exercises like puzzles or word games). Both of these promote hippocampal neurogenesis (the creation of new neurons), whereas physical and mental inactivity can lead the brain to shrink.

(Shortform note: While aerobic exercise is particularly helpful for preventing Alzheimer’s, it may result in injury if not paired with strength training. Falls are the number one cause of injury and injury-related death in those over 65, so it may be best to follow a multimodal exercise program (one that incorporates both aerobic and strength training) in order to prevent both Alzheimer’s and exercise-related injury. And when choosing activities for mental stimulation, remember the acronym SAVE: Pick activities that are Slightly challenging, Absorbing, and Varied, and that Enlarge your knowledge—those that make you feel like a beginner at first.)

Genova also explains the importance of diet in Alzheimer’s prevention. She recommends diets like the Mediterranean and MIND diets, which consist of a lot of leafy greens, berries, nuts, whole grains, and healthy fat sources like olive oil and fish. She notes that, contrary to popular belief, there’s no evidence that drinking red wine reduces the risk of Alzheimer’s and points out that drinking alcohol can actually increase the risk because it can disrupt sleep. And while chocolate and coffee show some promise due to their antioxidant properties and caffeine content, more research is needed to confirm their protective effects.

(Shortform note: It can be difficult to stick to a specific diet, but the MIND diet was ranked as the easiest diet to follow by the US News and World Report in 2016. Research also shows that it reduces Alzheimer’s risk even for those who only partially adhere to the diet (though less so than for those who adhere to it strictly). But while Genova advises against any alcohol consumption, the MIND diet recommends a glass of wine daily. And while chocolate and coffee aren’t included in the list of foods encouraged by the MIND diet, they’re also not on the list of foods to avoid (though the diet does recommend largely avoiding sweets, so it may be best to choose less sugary chocolates and unsweetened coffee).)

How to Forget

As mentioned earlier, forgetting is a key part of remembering, as it frees up space in your brain for important information. Genova provides various strategies for intentional forgetting at three stages of the memory-formation process. First, avoid paying attention to unwanted information in the first place, so you can refrain from encoding it. Turn your attention to something else that you would like to remember.

(Shortform note: To turn your attention away from what you don’t want to encode, you can try focusing on what’s going on around you, grounding yourself through your five senses until the unwanted stimulus is gone. You can also occupy your brain with tasks like listing words in categories, doing mental math, or reciting a poem you have memorized.)

Second, you can consciously get rid of information during the consolidation process, making a point to filter out information that you’ve encoded but don’t want to keep. (Shortform note: Genova doesn’t explain how you can consciously, selectively discard information during consolidation, but we can infer from what we’ve learned in this guide that it might help to disrupt the consolidation process by not giving your brain a break after encoding the information. Since rest is necessary for consolidation, you may be able to prevent it by avoiding rest for a few hours after learning.)

However, if you’ve already encoded, consolidated, and stored information you don’t want to remember, try to avoid exposure to cues that bring to mind those unwanted memories. Genova recommends that you consciously push it out of your mind and avoid retrieving the memory as much as possible, since every retrieval strengthens the neural connections that form the memory. If you can’t avoid the cues, consciously tell your brain to forget the information associated with those cues. This can disrupt the memory formation process and act as a neural signal to delete already existing memories.

(Shortform note: One way you may push a memory out of your mind to avoid retrieving it is by distracting yourself. However, experts warn against unfocused distraction, or letting your mind drift to whatever else happens to come up. This may actually create more pathways for retrieval, as each thing you casually distract yourself with becomes associated with the memory you’re trying to avoid. Instead, they recommend focused distraction: focusing on a single, chosen memory as a consistent alternative to the unwanted memory. A particularly effective focused distraction could be thinking of something in your life that’s currently incomplete, as we’re naturally more prone to remember something incomplete than something completed.)

In cases of trauma, memories can be particularly difficult to get rid of. Those with post-traumatic stress disorder often find that they can’t stop reliving or replaying memories of their experiences, which prevents them from forgetting them. To cope with this, Genova recommends a therapeutic approach that involves recalling the memories and deliberately changing them—a process known as reconsolidation—making use of the brain’s malleable reconstruction process to transform them into less painful and more neutral or positive memories.

(Shortform note: While reconsolidation-based therapies appear promising for helping those with traumatic memories, evidence for its effectiveness is somewhat lacking. Experts suggest that, in order for the treatment to be effective, both declarative and implicit memories must be susceptible to reconsolidation. Research seems to support the idea that implicit memories are susceptible to reconsolidation, but more research is needed to determine whether the process can be generally applied to declarative memory.)

Finally, in order to “forget” muscle memories, you have to replace them with new muscle memories. Here, the key again is repetition. You have to do it again and again until the new memory is stronger than the old one. For example, if you taught yourself to play an instrument like a recorder, you may have picked up some incorrect techniques, like placing your right hand above your left (the correct technique is to place the left hand above the right). If you decide to move up to a woodwind instrument like a clarinet, you’ll find that the right-hand-on-top technique will prevent you from playing the instrument correctly, so you’ll need to replace the muscle memories you’ve developed with muscle memory of the correct, left-hand-on-top technique.

(Shortform note: Another reason you may want to replace old muscle memories with new ones is if you’ve learned improper form for certain physical exercises, or if an injury has led you to develop poor posture that results in chronic pain. One way to override these muscle memories is through neuromuscular therapy, which uses practices like massage and trigger points to retrain your muscle memory. However, even with the use of these therapies, repeatedly practicing the new, desired form is necessary for lasting change.)