Scientific American Editors - Remember When?: The Science of Memory

THE SCIENCE OF MEMORY

From the Editors of Scientific American
Cover Image: artisteer/Getty Images
Letters to the Editor
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Published by Scientific American
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ISBN: 978-1-466833883

Introduction: The Science of Memory

We dont often marvel at the process of rememberingthat is, until we forget. What allows us to remember, and how do we forget? Most importantly, why do we remember certain things and not others? More than 50 years of research has shown that certain areas of the brain are memory centers which specialize in remembering; and that there are different types of memory, including the ability to remember facts, experiences, or how to do things.

In this eBook, we explore what science can tell us about memory, starting with Section 1, "What Is Memory?" In a surprising piece by Gary Stix, You Must Remember This Because You Have No Choice, he explores why some people can remember what they had for lunch on a Tuesday 20 years ago while others cant. Theres also a fascinating Q&A with Eric Kandel, neuroscientist and psychiatrist who won the Nobel Prize for his groundbreaking work on how neurons fire together in order to store memories in the brain.

In Section 2, we explore the "Anatomy of Memory," from how memories are saved to how theyre transferred from short-term storage in the hippocampus to long-term storage in the cortex. Several excellent features by leaders in the field lay down intriguing new theories as to how memories are temporarily stored, consolidated for long-term retrieval, and accessed. One re-examines the grandmother cell hypothesisone neuron for one memorywhile another shows why emotional experiences make stronger memories.

"Learning and Memory" is the topic of the third section, with a great story by Joe Z. Tsien, "Building a Brainier Mouse," describing his technique of genetically tweaking certain receptor proteins on neurons to create smarter mice. Another story links white matter to learning; while a third examines how our brain uses the time during sleep to encode our perceptions into long-term storage for easier retrieval later on.

Section 4 takes a look at some spooky aspects to human memory, including amnesia, hypnosis, and dj vu. In Section 5, we delve into memory and traumaand how researchers are slowly but surely narrowing in on specific behavioral techniques as well as drugs that can help to alter painful or traumatic memories after the fact. For war veterans suffering from PTSD, notes long-time journalist Jerry Adler in his piece on the subject, this could be game-changing for the future treatment of people suffering from the emotional fallout of traumatic events.

Section 6 delves into memory and aging; its well known that the ability to recall things diminishes as we age, but in lieu of being diagnosed with dementia, the causes remain mysterious. Several stories capture the essence of how to stay fit, both mentally and physicallywith regular exercise. In "Aerobic Exercise Improves Memory in Older Adults," Katherine Harmon discusses the science behind it.

Finally, the last chapter looks at ways to improve your memory. One story links dreaming to improved learning. In "A Pill to Remember," R. Douglas Fields summarizes the work behind the idea of a smart pill, based on the relatively recent discovery that a specific protein kinase might boost memory and therefore, could be given in pill form to enhance that most mysterious process.

-Jeanene Swanson
Book Editor

Why Is Memory So Good and So Bad?

by Julian De Freitas

What did you eat for dinner one week ago today? Chances are, you cant quiterecall. But for at least a short while after your meal, you knew exactly what you ate,and could easily remember what was on your plate in great detail. What happenedto your memory between then and now? Did it slowly fade away? Or did it vanish,all at once?

Memories of visual images (e.g., dinner plates) are stored in what is called visualmemory. Our minds use visual memory to perform even the simplest ofcomputations; from remembering the face of someone weve just met, toremembering what time it was last we checked. Without visual memory, wewouldnt be able to storeand later retrieveanything we see. Just as a computersmemory capacity constrains its abilities, visual memory capacity has beencorrelated with a number of higher cognitive abilities, including academic success,fluid intelligence (the ability to solve novel problems), and general comprehension.

For many reasons, then, it would be very useful to understand how visual memoryfacilitates these mental operations, as well as constrains our ability to performthem. Yet although these big questions have long been debated, we are only nowbeginning to answer them.

Memories like what you had for dinner are stored in visual short-term memoryparticularly, in a kind of short-term memory often called visual workingmemory. Visual working memory is where visual images are temporarily storedwhile your mind works away at other taskslike a whiteboard on which things arebriefly written and then wiped away. We rely on visual working memory whenremembering things over brief intervals, such as when copying lecture notes to anotebook.

The question is: when are these memories wiped away? And when they are, can we still discern traces of what was originally written, ordoes nothing at all remain? If visual short-term memories are only gradually wiped away, then remnants of these memories should stillbe retrievable; but if these memories are wiped out all at once, then we shouldnt be able to retrieve them in any form whatsoever.