SUBLIMINAL EYEWITNESS ACCOUNTS

Justitia, Heemskerk

I wrote a blog two years ago titled The Catch recalling a memory of over sixty years that occurred when I was a boy playing in my first All Star baseball game.  And this memory has popped up in my mind’s eye off and on all of my life. It wasn’t an experience that the hundred or so other people who witnessed it were even aware of at the time. I alone knew that it was special.  I don’t recall the exact time or place or much else about the game, including whether we won or lost!  I just mainly remember the catch.  Leonard Mlodinow has written a book titled Subliminal about how our unconscious mind rules our behavior.  He covers some extraordinary new research on how our behavior and memory function.  Mlodinow notes that the unconscious tier of our mind is more fundamental than our conscious mind and it is the standard infrastructure in all vertebrate brains that ensures our survival and ability to pass along critical DNA genes.

 

The human sensory system sends the brain about eleven million bits of information each second.  The actual amount of information we can handle has been estimated to be fifty bits per second at most.  Scientists estimate that we are conscious of only about 5 percent of our cognitive function.  The majority goes beyond our awareness and makes our lives possible.  Even if our conscious mind is idle, our unconscious mind is always active!  That’s why it’s always a good idea to "sleep" on a vexing problem and awake with a solution.  One of the most important functions of our unconscious is processing data delivered by our eyes and about a third of our brain is devoted to processing vision.  We receive images in two dimensions and our unconscious creates three dimensions.  Many of us know that these images arrive upside down and our brain presents them to us right side up.  But did you know that there’s a blind spot right in the center of every image due to the connection between our retina and our brain?  However, the brain fills in the dead region based on the surrounding area.

There is a correlation between how the unconscious fills in the blanks for both our vision and our memories!  But that begs the question of how much of the result is accurate?  This question has far reaching implications for memory and eyewitness testimony.  Mlodinow relates that “The organization Innocence Project analyzed hundreds of people exonerated on the basis of postconviction DNA testing and found 75 percent had been imprisoned because of inaccurate eyewitness identification.  About seventy-five thousand police lineups take place each year and statistics on those show that 20 to 25 percent of the time witnesses make a choice that the police know is incorrect because these are ‘known innocents’ used to fill out the lineup.”

Our human memory system is far from perfect, but it’s good enough to retain the deep structure or gist of a situation and doesn’t let the surface structure which we only retain for seconds get in the way.  Later our unconscious fills in the estimated details based on our experience.  And if we bring a certain memory up repeatedly over time, we begin to remember the memory, not the original event.  I’ve read that we actually never recall the original event but our last memory of the event which may by now be somewhat corrupted, as in eyewitness accounts.

Mlodinow questions “Are we often wrong but never in doubt?  We might all benefit from being less certain, even when a memory seems clear and vivid.”