This Is Your Brain: The Guided Tour – Your Brain on Trial

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Narrator: As former U.S. Supreme Court Justice William Brennan once said, “there is almost nothing more convincing than a live human being who takes the stand, points a finger at the defendant and declares, ‘That’s the one!’”

But research on human memory and breakthroughs in DNA evidence show that eyewitness testimony is one of the least reliable form of evidence – despite what that 100th re-run of Law and Order would have us believe.

Studies conclude that about half of erroneous convictions are caused by inaccurate eyewitness statements.

It’s not that witnesses lie. It’s that our brains are not video recorders.

Very simply put, memories are formed when neurons carrying little bits of information – including sounds, smells, language, sights, emotions – form connections among brain cells. These “memory bits” are stored in compartments that are constantly being rearranged by our brain’s limbic system.

When we recall an event, we reconstruct the memory. With each reconstruction the memory may change. Gaps may be filled in.

Your brain may re-create a vivid memory, “but that doesn’t prove that what was re-created was true,” according to Dr. Marsel Mesulam, professor of neurology and psychiatry at Northwestern University.

Other factors result in inaccurate eyewitness accounts too. A team of psychologists from the University of Huddersfield showed experiment participants video footage of an actual bar fight.

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Actors “planted” in some of the participant groups were instructed to misidentify the person starting the fight. The results? Many eyewitnesses accepted the false information and would then include the “evidence” in their own statements. Some participants simply doubted themselves. But some – especially those with submissive or neurotic personalities – convinced themselves that they had also witnessed the false information.

We’ll give the last word to psychologist and human memory expert Elizabeth Loftus:

“Human memory is far from perfect or permanent and forgetfulness is a fact of life.”

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(off mic – Hey Tom! … Did you see where I put my other glasses?)

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