Eyewitness testimony has been the gold standard for criminal trials for a long, long time. If police could get identification from a victim or a witness, they could essentially proceed to trial without passing “Go”.  The same is true with civil trials. An eyewitness statement about who was at fault in an accident, or the condition of a mechanism (whether the witness had expertise or familiarity with that device or not) adds credence to an argument which transfers to credibility for the issues.

The irony is that when another person’s life, liberty, reputation or money depends on the reliability of a simple memory of something — and that ‘something’ may have been seen fleetingly, perhaps in bad light, without context or even a trick of the eye  — the percentage of false witness statements is very high.

 

1) Memories aren’t beyond influence.

One problem is that a lot of time may elapse between an event and when a trial takes place. Many people will have a lot at stake on the outcome, and will therefore try to influence the witness in some subtle way — sometimes with the intent to make the witness recall a more dangerous version.

A witness who described a perpetrator as a tall, young man could be shown a lineup of potential suspects with one tall young person (the person that the prosecutor may suspect and wish to convict) next to four other men who are shorter and older. Naturally, the witness will gravitate to the tall man. Later, in court, after the witness has been praised over and over for ‘making the right choice’, thereby validating his selection whether right or wrong — he will have the confidence to affirmatively ID the defendant at trial. The tall man could be innocent, and the real perpetrator could still be loose, and ready to continue his crime spree.

 

2) Memories can be manufactured.

In a recent study by Dr. Elizabeth Loftus, subjects were chosen to be ‘jurors’ in an experimental mock trial (in essence, a trial presented on evidence as if it was a real procedure, but without real consequences for the defendant, who is an actor). The ‘jurors’ were presented with facts about a robbery and a murder, and then were given a presentation by a ‘prosecutor’, followed by a presentation by a ‘defense attorney’. In the first version, the evidence was only circumstantial. The ‘jurors’ deliberated and came back with verdicts, and only 18% of the ‘jurors’ found the ‘defendant’ guilty.

The presentation was recreated for another group of ‘jurors’, but this time, there was testimony from an actor playing the clerk of the store which was supposedly robbed. With everything else kept constant, 72% of the ‘jurors’ found the defendant guilty.

Memories, as discovered in this test, can be manipulated depending on what is given to the subjects in order to influence the final opinion. Subjects given the first set of circumstantial facts remembered things differently than the people who were convinced that the evidence was supported by a witness. How the subjects accepted the information, then remembered it in order to deliberate has to do with memories being manufactured, in essence, being manipulated.

 

3) The old adages don’t apply.

Many people ssume that memory works like a recording device or a miniature video camera in our brains that takes in the facts as they are, and replays them to us at a later time in perfect synchronicity with what occurred.  Even Sigmund Freud taught that long-term memories are stored deep in the unconscious mind, too deep to be disturbed by current experiences, and these deep memories can haunt us and influence our behaviours forever. This is simply not true, and not biologically or physiologically possible. Like computers, our brain will break data up into tiny parts and store them wherever there is space. If links to the whole story are corrupted, the file is changed — or corrupted — in how it is recalled.

 

4) Memories can evolve.

Scientists describe the formation of memories as the result of neurons linking together inside the brain to form connections, changing cell contacts in a way that stores bits of information somewhere within our brains. Over time, we can collect up to a quadrillion (a million billion) bits of information in pockets which become crowded and densely packed. There is no order, and no hierarchy of importance applied to any individual bit. As we add new experiences and observations into these pockets in a random fashion, some information can be lost, some can be contaminated with other bits of information, and some can even be reconstructed to create an experience we never had.

 

5) Your brain can miss the point, entirely.

Test your own memory on things you have seen all of your life: can you recall which letters on a phone correspond to the number 5? Is it MNO (three letters for each number counting from 1 or is it actually JKL? (commit to an answer before you peek).

In a recent study, subjects were shown fifteen designs of a US penny coin. One was real, and the others were variations. After years of seeing, counting, looking at and owning pennies, less than half of the subjects remembered what the real coin looked like and could pick the correct version.

Christopher Chabris and Daniel Simons conducted a test — the invisible gorilla test —  where subjects were asked to watch a short video of three kids dressed in white tossing a basketball back and forth, and three kids dressed in black also tossing another basketball back and forth. The viewers were asked to count how many passes the white shirted kids made in 90 seconds. At the end, they were asked how many passes, but they were then surprised with another question. Did they see the woman in a gorilla suit walk through the video for nine seconds? Half of the viewers simply did not see it, and when they reviewed the video, accused the test givers of substituting a different video.

Memories can certainly fade, as old songs and poems proclaim, but they can also grow. Every time we recall a memory, it is reconstructed and can possibly change, being influenced by similar, more recent events, other people’s comments or suggestions or even a new understanding.

 

Your turn: Is the human brain a precise or imprecise recorder of events? Have you ever discovered that a strong memory you held was actually a fantasy?  Tell us about your experiences with fading or altering reality.

About The Author

Forensic Outreach has long been a dynamic and active part of classrooms throughout the United Kingdom and Europe. It was conceived as part of UCL’s Widening Participation programme in 2002 to introduce forensic science as an integrative and cross-disciplinary approach to science education.

2 Responses

    • Douglas Filter

      It has to do with how memories can be manipulated depending on what is given to the subjects in order to influence the final opinion. Subjects given one set of circumstantial facts remembered things differently than the people who were convinced that the evidence was supported by a witness. How they accepted the information, then remembered it in order to deliberate has to do with memories being manufactured, in essence, manipulated.

      Reply

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