ILLUSION MACHINE: THE BRAIN The 5 Errors of Our Perception
Our brain is an impressive construction: Weighing only around 3 pounds, it possesses roughly 100 billion nerve cells and the total length of its neural pathways measures about 100,000 miles. What happens here is reality— and that arises differently in each brain. Unlike a standardized measuring tool, each of us uses our own individual filters to execute perception. Our visual apparatus alone is considered to be particularly prone to error— even though 80% of our information comes through our eyes. All we can do is instantly interpret everything we see: The brain’s immediate analysis leaves no time for reasoning.
Shortly after midnight on July 19, 2015, engine noises and a loud crash have shattered the silence in the German city of Bremen. The sounds originate from a fatal traffic accident that is about to make national headlines. Two vehicles had been racing down the road side by side at 60 miles per hour, thereby blocking both lanes of traffic. The driver of an approaching Mercedes only had time to flash his high beams, and at the last moment the car had swerved to the right and knocked down a tree as well as a streetlight—at least that’s the way several eyewitnesses unanimously described it to the police. The 52-year-old driver of the Mercedes had been killed instantly, the victim of an illegal car race.
The problem: No part of the sequence of events happened in the way that the witnesses described. Video recordings reveal that there had not been any risky lane blocking. In fact, the Mercedes driver was found to have a blood alcohol level almost two times the legal limit, making him completely unfit to drive. However by that time the report had already reached the news services. On the Web, an unprecedented hunt began for the escaped “murderers,” for lax laws and idle politicians, and for people connected to the streetracing scene, whose names circulate in online forums. A virtual war ignited by false memories rages on for days. But how could a fiction turn into the truth in the minds of the witnesses?
HOW DOES THE BRAIN TRUMP THE EYES?
Three factors led to a tragic accident being transformed into a street race with fatal consequences that night. Factor 1: The accident took place on a warm summer night, which means many residents were sitting outside. The screeching of an engine would be clearly audible from where they were sitting, and it suggests racers. “The louder a vehicle is, the higher we estimate its speed to be,” says social psychologist Jörg HupfeldHeinemann. Factor 2: The immediate focus of the witnesses at the scene of the accident was only directed at the wreckage. Any details outside of that ( like cars racing side by side) are blurry. Factor 3: Illegal car racing was getting a lot of media coverage around the time of the incident, so it lent itself to an obvious explanation. Finally, residents often complained to the police about races occurring on the extremely straight roadway. “From the information available we construct the best possible story, and if it makes sense, we believe it. Paradoxically, the act of fabrication is actually easier when you have less information,” explains psychologist and Nobel Memorial Prize winner Daniel Kahneman. And that’s how, in a matter of hours, the “memory” of a race that never happened is born…
However that’s only the tip of the iceberg, because in this case video evidence quickly exposed the truth. But what if there’s no video footage? According to independent studies, more than half of all miscarriages of justice in court transpire as a result of incorrect eyewitness accounts.
“We create our memories ourselves. They do not necessarily correspond with what has happened before in the outside world.” HANS MARKOWITSCH, memory researcher
These come from people who were there and are simply repeating what they saw—supposedly. “Witnesses do not lie,” says Jennifer Dysart, an associate psychology professor at John Jay College of Criminal Justice. “Rather, they are subject to an error in their reproduction of reality.”
Studies show that just 30 minutes after an event we already start to mix up the details—much like a dream, the details are still clearly present in our consciousness shortly after we wake up but they become more and more hazy as the morning wears on.
The brain fills the resulting “blank spots” with data that fit the story— just as we immediately complete the sequence “1,2, 3, x, 5” by adding a 4. It is simply “logical,” and alternative explanations aren’t readily available. Darkness + the sound of an accident + limited sight + hatred of racers = racing. “Our perception is driven by subconscious hopes and goals. We usually see only what confirms our intentions,” says New York University social psychologist Emily Balcetis. By the time the witnesses had been questioned by the police, the “fitting” truth had taken root in their minds…
For criminologists such “invented” realities do not come as a surprise. They are happening even while you read this, albeit on a smaller scale: Approximately every three seconds you are blind for 150 milliseconds— whenever you blink to keep the tear film of your eyes intact. Only if you really focus on it will you notice the brief interruption. Normally the visual film is not “jerky” because the brain replaces the instant of darkness with a suitable sequence from memory.
The reality in the brain doesn’t arise as a reflection of reality, but rather as a glimpse of it through a keyhole. Illusionists like David Blaine turn the spectator’s brain into an accomplice: They position the keyhole so skillfully that viewers experience the trick as reality. “Everything we perceive is a manipulator of our consciousness,” says psychologist Daniel Kahneman.
WHY DO CHILDREN SEE BETTER THAN ADULTS?
Each human eye possesses more than 126 million color and contrast receptors, and these transmit data more than 11 million times a second. But the brain can really only process 40 of these impressions, so all the rest end up in the virtual trash bin. It’s like judging a novel after reading just four words. But for our brain this “sloppiness” is not a problem, since it concentrates on the order—rather than on the understanding: Its daily life is a single and rarely interrupted sense of achievement: “I know this, I understand that, these fit into that compartment.” The brain checks off 99.9% of all impressions this way— regardless of whether they are true or not. “This scan is only disturbed by impressions that are unexpected, frightening, or particularly desirable,” explains Balcetis.
Like sleepwalkers, we are steered through life by our brains: “It takes only a tenth of a second to render all sorts of judgments about a face that you’ve never seen before,” explains Alexander Todorov, a psychologist at Princeton University. In the process,
it’s not only gender, age, and mood that are taken into account, but also how helpful, nervous, or intelligent the person seems to be. Depending on the circumstances, this tenth of a second can determine whether we approach a person or steer clear— or if we make the person a suspect in a crime. “I often ask myself, ‘Who is the boss here? Who’s in control?’” says neuroscientist Allan Snyder, director of the Centre for the Mind at Australia’s University of Sydney. “And the only answer always is, our subconscious. It downright dictates our decisions. And the conscious mind is merely the brain’s PR stunt so that we think we have some say.”
The artificial reality in our heads is well protected against facts. Once obtained, “findings” are not checked—the brain hasn’t any time: Because the sensory centers are already focused on the next piece of information, and incoming data are streaming in and require interpretation so they can be made to fit into a pattern. The result: “We live continuously in our illusions. There is never or only very, very rarely a 100 percent correlation between reality and our perception,” explains Susana Martinez- Conde, head of the Laboratory of Integrative Neuroscience in Brooklyn, New York. The laziness of the brain makes the deception within our heads perfect: “Humans are cognitive misers,” says psychologist and author Lars- Eric Petersen. “The brain attempts to get through life doing the least amount of heavy thinking possible.” And so, paradoxically, this means infants are superior to us with regard to thought patterns because their brains are still like a blank sheet of paper. They take in their environment impartially and much more accurately—simply because there is less stored material against which to compare new data.
But in certain circumstances, this mental mode can be life-threatening. While a young child might stay still and marvel at an oncoming car, an adult would take countermeasures: We “see” the imminent peril—even if the driver may long since have been ready to brake. University of Bristol neuropsychologist Richard Gregory has confirmed: “Yes, the brain plays tricks on us all the time—but without these illusions, we couldn’t survive.”
“THE BRAIN PRESENTS THE WORLD TO US ONLY IN A VERY LIMITED SCOPE. OF THE HUGE RANGE OF AVAILABLE SIGNALS, WE TAKE IN BUT A SMALL PART.” WOLF SINGER, brain researcher