Remember Summary

"Memory is the diary we carry about with us.” But what happens when that diary has missing pages or edits itself over time? Lisa Genova's Remember takes us on a journey to understand the marvels and pitfalls of memory.

1. Memory is formed through focused attention and a process of encoding and consolidation.

Memory is not just a vague abstraction; it has a physical component in the brain. When you focus on a specific experience or moment, sensory data is first encoded in the prefrontal cortex before passing to the hippocampus. There, it’s consolidated into a stable neural pattern that becomes a long-term memory.

The process of encoding requires attention. Without clear focus, the sensory information may not even reach the hippocampus for consolidation. Think about studying for a test; half-hearted glances at the material are unlikely to lead to meaningful retention. Repeated exposure to something, like learning a song lyric or reviewing a penny's design, can fortify the encoding process.

Memories are split into three key types. Semantic memory includes facts or general knowledge, like remembering a barista's usual orders. Episodic memory relates to significant moments tied to a time and place, such as the birth of your child. Finally, muscle memory involves physical tasks, created through repeated practice in the motor cortex.

Examples

• Paying attention to the details of a penny allows your brain to encode its image better.
• A barista recalls orders through semantic memory reinforced by daily repetition.
• Episodic memories, like a wedding day, involve the hippocampus anchoring them to a specific moment.

2. Powerful episodic memories can be unreliable.

Vivid memories from impactful events may seem crystal clear, but they are often incorrect. Studies have shown how memories of historical disasters or personal traumas tend to morph over time. The more we recall them, the more we unknowingly modify their details to align with current beliefs.

One well-documented study involved students recalling what they were doing when the Space Shuttle Challenger exploded. Two years later, their "accurate" memories had changed, yet many insisted their new versions were correct. This reflects how memory formation is influenced by biases and imagination during retrieval and reconsolidation.

Even when not accessed, memories decay over time. As the neural pathways weaken, recall becomes dotted with gaps. To fill in these gaps, we unconsciously invent details. This applies a present-day narrative to past events, illustrating how memory shifts continuously.

Examples

• The Challenger study participants confidently misremembered vivid moments of the tragedy.
• Forgetting details, like the layout of a familiar room, happens as neural links fade over time.
• People often “rewrite” their perceptions of past relationships when reflecting from a different emotional state.

3. Muscle memory resides in a different part of the brain.

Muscle memory doesn’t depend on the hippocampus, the brain region responsible for consolidating other forms of memory. Instead, it’s created in the motor cortex, where repeated physical actions strengthen pathways. This explains why even someone without the hippocampus can acquire new motor skills.

Henry Molaison, whose hippocampus was removed to treat seizures, couldn’t form new long-term memories. Yet, when asked to practice mirror drawing (a skill requiring highly specific coordination), he improved over time. Though unaware he was practicing the skill repeatedly, his motor cortex established the muscle memory necessary to excel.

Muscle memory becomes automatic with consistent repetition, requiring no conscious thought once ingrained. This is why we can walk, ride a bike, or type fluently without deliberate effort. The brain’s motor cortex transforms repeated physical acts into stable and efficient neural patterns.

Examples

• Henry Molaison successfully learned mirror drawing even without memory of prior practice sessions.
• Musicians develop muscle memory for complex finger movements by practicing scales daily.
• Athletes fine-tune muscle memory for specific moves, like a hurdler clearing obstacles with precision.

4. Forgetting is part of a healthy brain function.

As frustrating as forgetting may seem, it serves an important purpose. A brain overflowing with meaningless details would struggle to prioritize or focus. Forgetting allows us to let go of irrelevant information and make room for meaningful memories.

Our working memory, which processes sensory information in real-time, helps decide what’s worth remembering. For instance, on a familiar drive home, you filter out nonessential details like repetitive billboards. Forgetting also helps us move past negative or traumatic memories—although this process may be far harder when dealing with lasting emotional scars like PTSD.

Interestingly, those who can’t forget, like Solomon Shereshevsky, experience mental clutter that impairs their ability to function. Their inability to let go of even mundane information highlights forgetting as an essential mechanism for mental clarity.

Examples

• Working memory disregards irrelevant details from familiar daily routines, like billboards on a commute.
• Therapeutic methods, such as imagining rewriting a traumatic ending, help those with PTSD reshape painful memories.
• Solomon Shereshevsky’s life demonstrated how perfect memory can hinder rather than help.

5. Prospective memory is notoriously unreliable.

Prospective memory—the ability to recall an intention for the future—is one of the shakier aspects of human memory. This is why we frequently forget errands, like picking up milk or remembering to call someone back. Stress or distraction adds to the likelihood of forgetting.

Even Yo-Yo Ma, a musical genius with an incredible memory for music, forgot his $2.5 million cello in the trunk of a cab. Prospective memory creates a mental to-do list that’s often prone to failure without external prompts. High-stakes environments, like surgery, have implemented checklists to prevent such lapses.

For everyday tasks, using reminders like apps or sticky notes can bridge the gap left by unreliable prospective memory. These external tools alleviate the need to rely solely on the brain to keep track of everything.

Examples

• Forgetting to bring a bottle of wine to a dinner is a lapse in prospective memory.
• US surgeons left objects inside patients 772 times in a five-year span due to lapses in prospective memory.
• Yo-Yo Ma left his cello in a cab because he didn’t place reminders or physical cues to help avoid forgetfulness.

6. Name recall demonstrates memory’s selective nature.

Names can be difficult to remember because our brains struggle to attach meaning to them. However, when names are connected to descriptive traits, we’re better able to recall them. This highlights how memory prefers narratives over isolated abstract details.

Imagine meeting a man named Baker. If you think of him as someone who bakes delicious bread, you are more likely to remember that than if Baker were simply his surname. Similarly, memory champions use mnemonic techniques to turn abstract data into visual stories.

This tendency to prioritize meaning and visualization enables remarkable feats of memory but also explains why we forget details lacking context or relevance. Transforming rote facts into associations can make them stick more effectively.

Examples

• Memory expert Akira Haraguchi transformed numbers into images to remember digits of pi.
• We may recall a baker's profession but forget their surname because “baker” has sensory connections to smells and tastes.
• Visual storytelling boosts recall more than abstract study methods alone.

7. Memory naturally weakens with age.

As we grow older, we tend to notice more lapses in memory. These can range from forgetting where we left our glasses to losing details in the episodes of our lives. While these occurrences are frustrating, they are normal.

With age, the brain processes information more slowly, reducing the efficiency of forming and retrieving memories. Episodic memory, responsible for life’s snapshots, becomes patchy, while prospective memory continues to decline. However, these changes don’t necessarily signal dementia.

Alzheimer’s causes memory loss of a different severity, often beginning with the buildup of amyloid plaques in the brain. While age-related memory gaps are mildly irritating, Alzheimer’s creates profound challenges, like forgetting how to use household objects.

Examples

• Forgetting keys is common in aging brains, but those with Alzheimer's might not remember how keys function.
• Tip-of-the-tongue moments increase as neurons age and firing becomes slower.
• Slower consolidation explains why older adults might confuse timelines in episodic memories.

8. Lifestyle plays a role in memory retention.

By leading an engaged and mentally active life, you can strengthen your brain and slow memory decline. Studies of nuns engaged in cognitively rich activities, like education, social tasks, and purposeful work, showed fewer symptoms of dementia despite physical signs of Alzheimer’s.

Mental stimulation fosters new neural pathways, which can bypass damaged ones caused by amyloid plaques. Physical health also ties directly to brain health, with inadequate sleep, stress, or poor nutrition compromising memory. A well-rested brain, unburdened by toxic stress, performs optimally.

Adopting routines like mindfulness or gratitude is another effective way to nurture the hippocampus. These practices help reduce stress hormones and support cognitive resilience.

Examples

• Nuns who pursued education and hobbies displayed preserved cognitive function despite brain pathology.
• Practices like gratitude help alleviate chronic stress tied to memory impairment.
• A lack of sleep directly hampers the hippocampus’s ability to consolidate memories.

9. Strategies can improve memory performance.

There are abundant methods to strengthen memory. By creating mental stories, visualizing data, or utilizing physical cues, you can retain information effectively. Memory techniques work especially well when combined with focus and repetition.

Memory champions often assign abstract data to highly visual images. For instance, numbers can become pictures, and names can be tied to imaginative scenarios. Frequent testing, such as quizzing yourself on key concepts, locks new information into place over repeated sessions.

External tools like lists, calendars, or highlighted notes bolster performance too. And it’s perfectly fine to use smartphone alarms or sticky notes—these don’t harm natural memory but enhance it.

Examples

• Joshua Foer transformed random numbers into vivid imagery to win a memory competition.
• Highlighting and visualizing new information boosts retention.
• A checklist helps prevent forgetting vital errands or tasks, such as booking appointments.

Takeaways

1. Enhance focus and repetition to solidify important information in your memory.
2. Build a brain-friendly lifestyle with proper sleep, mental challenges, and stress management.
3. Use external memory aids like alerts, lists, and visuals without guilt—they complement your mental efforts.