Is it the truth? |

Is it the truth?

Alan Braunholtz

We’re about to get an intense tutorial on how the justice system and national media work in practice. Justice and the media should be only interested in the truth. Sounds simple, but in my experience nailing down the truth is almost an impossibility.

People lie and we’re not very good at spotting them. Most of us do no better than chance at identifying liars. Either we don’t want to label people as liars or their skills are winning in this evolutionary arms race, though trained people can recognize liars.

The Secret Service and prison inmates are good at it. Both live in situations where they’re exposed to a lot of deceit and it’s important to tell who is telling the truth.

Strangely, world renowned emotion researcher Paul Ekman found a Tibetan Buddhist monk the best at detecting the truth. I guess focus and empathy really count. The secret appears to be the ability to detect fleeting micro expressions of the face that last less than 40 milliseconds. Pity we don’t have too many Tibetan monks in our jury pools.

Our memories aren’t as good as we like to think. I have some very different memories of my wedding compared to my wife. Who is right? Short of playing the video, who knows? If the video is edited then is that accurate?

Even long-term memories aren’t stable. When we recall a memory, it becomes completely fluid and open to suggestions, embellishments or even being erased before it is fixed back into the brain. My high school sweetheart gets prettier every year. The concept of a permanent long-term memory is probably a myth.

Memories are created by a complex series of brain events. Short-term memory traces are the result of brain neurons creating a moment’s snapshot by firing in a distinct pattern. These neurons remain aroused and ready to repeat the pattern or memory snapshot. This trace lasts only a few seconds before the brain turns them into something more permanent. The memory is fixed first by the synapses that connect these neurons swelling and creating stronger connections so the pattern is maintained. In a few hours the neurons creating the memory trace physically grow, effectively wiring in a permanent memory. This growth requires a lot of protein.

Initially, this wired memory is stored in specialized regions of the brain like the hippocampus. Over time the memory somehow moves to the dusty vaults of the brain’s cortex. It’s a little harder to find but supposedly a permanent reference.

Experiments with mice prove that long-term memories can be played with. Mice were placed in a box and zapped. The mice remember this and freeze whenever placed in the box. After 45 days this memory should be filed in the cortex and unchangeable. Experimenters gave these mice a drug that blocked the synthesis of protein, effectively preventing the fixing of any new memory. For one group this had no effect; they still froze when placed in the box, their long-term memory intact. The other mice saw the box just before receiving the drug. These forgot all about the shock and happily walked around inside the box. Seeing the box brings the memory out of storage and once there it must be refixed. The drug prevented this. Recalling a memory made it susceptible to change or in this case, erasure,

So how reliable is our memory? Experience suggests its pretty good but its not etched in stone, either. Our memories are dynamic things. We are constantly adding new experiences on to old ones, i.e. learning. We use memories to make sense of our present world and being able to update, connect and refile memories helps. This constant refixing is as likely to strengthen a memory as erase it, though.

Still, this explains how eyewitness accounts of the same event can differ. Elizabeth Loftus’ eyewitness research at the University of California shows that people will incorporate overheard or suggested details into their memory as if they saw it. Psychotherapists and criminal investigators can create false memories if they’re not careful. In a photo lineup of mug shots missing the actual perpetrator, the victim may make a relative choice, picking the closest looking face and then that face will become the memory.

Then you have forensic science. DNA testing is the gold standard here. DNA testing came from clinical medicine with rigorous peer review and comprehensive evaluation.

Other tests involving toxicology and chemicals followed this route and look to be very accurate.

Much of the rest of forensic science seems to be an oxymoron. Hand-writing analysis is something fortune-telling gypsies do. Hair comparison, a staple for 75 years, looks way too subjective. A recent study by the FBI found that 11 percent of hairs matched by experts were not if you compared mitochondrial DNA. Eleven percent error is a bit high for sending people to prison. Even fingerprints, if smudged or partially relied upon human judgement can lead to mistakes.

DNA testing, because it is so accurate, is revealing the shortcomings of other previously unassailable evidence. For more on this, check out the book “Actual Innocence: When justice goes wrong and how to make it right.”

I’m guessing few jury trials have incontrovertible evidence either way. If they did, would there be a trial?

Juries have a tough job. First they have to bury any preconceptions and presume innocence, both hard to do before sifting through contradictory stories and evidence of varying quality.

I guess it comes down to their judgment of who is telling the truth and whose memories are more reliable.

I can see how important jury selection is to the outcome. In an ideal world it shouldn’t, but we all see truth a little differently.

Alan Braunholtz of Vail writes a weekly column for the Daily.

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