Can We Trust Memory?

Memory – how good is it?  The law favors memory – we make witnesses tell their stories months or years after an event but preclude use of their diaries or memos to the file.  And memory reliability gets ‘politicized‘ – those who prosecute often default in favor of trusting memories long after the event, while those who defend cast aspersions calling memory untrustworthy, subject to distortion, and at risk of suggestion and manipulation.

In the field of psychology, the understanding of memory has largely been one that recognizes it as fragile and malleable; but again, as much of that research has been by (or adapted by) those who apply it forensically – eyewitness researchers – it again has its skeptics.

Where is this leading?  To another field, neuroscience.  Can brain activity/measurement help us understand memory and confirm what parts of the psychological research are valid?

The answer is decidedly “yes,” and it is found in a wonderful new book, REMEMBER (Harmony Books 2021).  It is reader-friendly, designed for a general audience; and the author’s credentials are impeccable – an undergraduate degree in biopsychology and a Ph.D. in neuroscience.  And she is not a forensics person.  She just cares about memory – how it works, where it can be improved, and how to help us as we age.

That person is Lisa Genova, author of the earlier work STILL ALICE and the lecturer whose Ted talk on “What You Can Do To Prevent Alzheimers” has been viewed millions of times.

REMEMBER is not written for judges or lawyers or police; it is meant to educate everyone about the nature of memory; about why it degrades over time both in terms of specific recollections and as a working process; and what alzheimers is and what steps may forestall or reduce its impact.

But reading REMEMBER gives one a primer on the memory we rely on in investigations and adjudications.  We learn of types of memory – for example, “semantic memory,” the storing and recalling of facts (who the first President was); “muscle memory,” the recall of ‘how to do stuff;’ and “episodic memory,” the capture, storage and recall of events.  We learn about the links among emotion, the release of chemicals in the brain, and memory creation and strength.  And, of course, we learn some brain science, such as the role of the hippocampus.

There is more.  Psychologists who describe memory see it as a three-stage process – encoding (the initial capture); storage (holding in the brain); and retrieval (bringing the memory back up for use).  Genova adds a fourth, one that follows on the heels of encoding.  It is called “consolidation” – the brain “link[ing] the previously unrelated collection of neural activity into a single pattern of associated connections.”

So if this book is about the process of memory, what does it tell us that is of forensic value?  This is especially important as events associated with emotions – as many crimes or other events that bring witnesses to court are – are remembered more strongly.  As Genova puts it, “Life events that are infused with emotion are what we tend to remember long term.  But that doesn’t make them reliable.”

Let me quote some passages:

  Your episodic memories are chock-full of distortions, additions, omissions, elaborations, confabulations, and other errors.  Basically, your memories for what happened are wrong.

To begin with, we can only introduce into the memory creation process what we notice and pay attention to in the first place…We only encode and later remember certain slices of what happened…From the get-go, our episodic memories are incomplete.

  In the process of consolidating an episodic memory, your brain is like a sticky-fingered, madcap chef.  While it stirs together the ingredients of what you noticed for any particular memory, the recipe can change, often dramatically, with additions and subtractions supplied by imagination, opinion or assumptions.

REMEMBER, then, confirms the lessons about the limited reliability of eyewitness memory.  It offers the reader ‘hard science’ support for this along with a humane understanding of how we can survive and indeed thrive by knowing memory’s limits and learning tools to enhance and support it.  Read REMEMBER for your own satisfaction and to learn how to work toward improved accuracy of recollection; but for those who are in the trenches of investigation and litigation, use this book to ‘remember’ how imperfect an act ‘remembering’ is.