Blue Line

DEEP BLUE: Your brain can fill in the gaps

July 4, 2016  By Dorothy Cotton

990 words – MR

Your brain can fill in the gaps

by Dorothy Cotton

Gotta love a good conference – particularly when it gives you an excuse to travel to nice places. So there I was in Victoria, new ideas and brilliant thoughts filling my mind at a big psychology conference. I was particularly keen on a presentation by Dr. Geoff Loftus, who spoke about the practical implications of his work around perception and memory and how it plays out in the real world.

Dr. Loftus spent the early part of his career locked away in a laboratory doing basic science, but it occurred to him that it might be useful to actually apply some of the things he had investigated in the lab. If you have ever wondered what conceivable use psychology research might be to you in your everyday work, here’s a good example.

Some years ago in Alaska there was an unfortunate encounter between a train and pick-up truck. For the sake of simplicity, let’s say the train was running north on a north/south track, and the truck was heading northwest on a northwest/southeast road. Engineer Goodbody, a nice, reliable, honest-as-the-day-is-long kind of guy, was in the locomotive and the Bozo brothers, both drunk as skunks and well known to police far and wide, were in the truck.

Bobo Bozo, who wasn’t wearing a seatbelt, was ejected and landed (splat) by the side of the road. His brother Ratling WAS belted up and died when the truck exploded.

Goodbody quickly stopped the train, ran back to Bobo and administered first aid until emergency services arrived – which takes quite awhile in the middle of Alaska. Oddly enough, Bobo survived. The question: who was driving the truck?

Goodbody was shocked, unaware that there was a second person in the truck. “I could tell there was going to be a collision just before it happened,” he said in his statement. “I saw the truck… it could not have been more than ten feet away… I remember Bobo’s face as clear as day – he was driving. We actually made eye contact. I couldn’t understand why he did not stop the truck!

“Yeah, he was driving. I don’t know where the other guy was, maybe bent over or something… but I absolutely saw Bobo. Like I said, I saw him clear as day and he was only a few feet away.”

The driver question was relevant since if it was Bobo, he would be charged with vehicular homicide. Bobo insisted that Ratling was driving. It was Ratling’s truck so that would have made sense, but Goodbody appeared far more reliable and credible. Bobo was charged and the case went to court.

Minor detail: An analysis of the accident showed the truck actually made contact with the train car behind the engine. Given the speeds both vehicles were travelling and the angle of impact, Goodbody could not possibly have seen, let alone made eye contact, with the driver. He likely could have see the truck for a fraction of a second before it hit the train, but any level of detail beyond that was simply impossible.

The truck was never closer than 70 feet to the engineer, and even at that it was behind him, where his view of it would have been obstructed.

Goodbody was adamant; adamant but wrong. He could not have seen what he thought he did. How can that be? Was he just lying because Bobo was a scuzbucket?

Here’s where perception and memory come in. There are good reasons why Goodbody might both misperceive and misremember the event.

  1. Stress: Our cognitive abilities are not at their best under periods of acute stress. It’s likely that Goodbody become aware in the spilt second before impact that there would be a collision. This qualifies as stressful. Therefore, his perception of even the details he COULD see were likely distorted.

  2. Short duration: He could only see the truck for a split second. When people see something only fleetingly, their brain likes to fill in the blanks. Since we know trucks have to have drivers, even though Goodbody could not see him, his brain filled in the gap and more or less created a driver.

  3. Lack of attention: If you saw a truck about to hit your train, your attention would not likely be directed to the driver or their eyes. You’d be looking at the truck, the space between the truck and the train or even the train. Again, your brain fills in the gaps with what it thinks ought to be there.

We also know that our brain takes information learned after an event and inserts it into the event itself. Goodbody did not know there was a second person in the truck, so naturally, when he created his visual image of the truck, the only face available to insert was Bobo’s.

It is also likely that Goodbody’s brain was madly reconstructing the mental scene while he administered first aid to Bobo – even more reason to insert the only available image.

Memory is tricky. We like to think of it as a digital recorder but it is really more like a stenographer taking shorthand back in days of yore. You tend to get most of the basics, but there are inevitably gaps later on when you recreate the story so your brain fills them in with whatever appears to make sense. (It’s kind of like the autocomplete function when text messaging. Mr. Google knows what words generally go together and guesses what should come next. It works much of the time but sometimes you get pretty funny messages.)

Goodbody was not lying. He was accurately relating his memory, but his memory was wrong. Bobo was acquitted.

As I am often reminded when absolutely positive that I put my car keys somewhere, and then find them elsewhere: just because you clearly remember something does not mean it happened.

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