It's hard to tell when your brain is playing tricks on you.
After all, your brain is both the agent and the recipient of perception, and whoa, uh oh, we think our minds just blew up.
Anyway, scientists and philosophers still have a lot to learn about the human brain and how it relates to subjective experience—where exactly the "subject" doing the "experiencing" is located, for one thing. Philosopher David Chalmers calls this the "hard problem of consciousness," and if you can understand his arguments, then you should be writing this article, not us.
So let's dispense with the heady question of how it's even possible for the same organ that gives rise to both perceiver and perception to trick itself. Let's just look at the most bizarre of these instances.
You'll definitely recognize some, if not all of these. It turns out that everyone's brain is a tricky little son of a gun.
1. Earworms: The "In West Philadelphia..." Problem
We've all suffered from these pests. Sometimes you get just a snippet of a song—the guitar lead from Eric Clapton's unholy abomination "Wonderful Tonight," say—and it's like your brain hit the repeat button and then fell asleep.
Earworms can get stuck in your head for days at a time. Sometimes the only way to drive them out is to replace them with another earworm. "Total Eclipse of the Heart" by Bonnie Tyler tends to work pretty well for us.
If you want to give '90s kids an incurable earworm, by the way, just walk into a room and sing the first three words of the Fresh Prince of Bel-Air theme song. You'd better wear your running shoes, though, because people do not appreciate it when you infect them with an earworm.
Psychologists are still studying this phenomena to figure out why exactly your brain gets stuck in an audio loop, but until they figure out the reasons, at least they have some advice to help get rid of them. Concentrate on something else, they say, like a crossword puzzle or decoding a list of anagrams.
2. Phantom Memories
What are you if not the sum of your memories? If the memories really do make up the character, though, humans prove to be awfully chimerical creatures.
That's because memory is incredibly malleable. We may remember the events of our childhoods in ways that don't conform to truth. We may even remember things that never happened at all.
In 1997, researcher James Coan wrote booklets describing childhood events and gave them to his family members to read. He snuck a fake into his brother's booklet—a detailed account of the brother getting lost in a shopping mall.
Later, when he asked his family to remember the stories from the booklets, Coan's brother recalled the "lost in the mall" story as real. He even unconsciously invented his own details. As far as he was concerned, this memory was as vivid as any other childhood scene.
We're not sure exactly how memory works, but one thing is for sure: You can't always trust it.
3. Believing Lies
If the "fake news" debacle of 2016 has taught us anything, it's that facts don't have to be true for millions of people to believe them. That's kind of the brain's fault, as it turns out.
A 2016 literature review from Northwestern University suggests that there are two operations that lead people to believe blatantly untrue statements. First, when confronted with a purported fact, it's simply easier to believe it than to analyze and evaluate it. The brain is busy. Sometimes it can't spare the resources to consider statements skeptically.
Then, when confronted with a problem, the brain retrieves the last relevant information it consumed—even if it isn't true.
“We often assume sources are reliable," said psychologist David Rapp in a press release about the study. "It’s not that people are lazy, though that could certainly contribute to the problem. It’s the computational task of evaluating everything that is arduous and difficult, as we attempt to preserve resources for when we really need them.”
4. Word Dust
Have you ever sat there and repeated the same word over and over until the meaning drained away completely? That's a well-documented phenomenon called "semantic satiation."
You can blame your cortex for any discomfort this exercise may cause. When you say a word, the cortex retrieves the meaning of that word. If you repeat the word many times quickly, that neural pathway begins to weaken with each repetition. Eventually the stimulus (saying the word) ceases to cause the neural activity (the firing of a pathway to meaning).
Interestingly, scientists have found ways to use semantic satiation therapeutically. It can help with stuttering, for instance, and even with the uncontrollable use of profanity sometimes associated with Tourette syndrome.
(FYI: Most people who have Tourette syndrome don't exhibit coprolalia, or the uncontrollable use of socially inappropriate words, no matter what the movies say. Semantic satiation, on the other hand, is very real.)
5. Believing What You Want to Believe
If you've ever gotten in a political argument on an online comments thread, you're familiar with a phenomenon the professionals call "motivated reasoning."
Essentially, the mind doesn't want its precepts and assumptions challenged by a pesky thing like reality. That means people are less likely to accept statements that challenge a previously held belief. Paradoxically, these challenging statements tend to make people cling even more tightly to their beliefs.
"If we believe something about the world, we are more likely to passively accept as truth any information that confirms our beliefs, and actively dismiss information that doesn’t," wrote reporter Joe Keohane in the Boston Globe.
This works both ways. You're more likely to believe false statements that support your worldview. You're also more likely to reject true statements that counter your worldview. Given that these tendencies are baked into the mind, it seems, any hope of a less-contentious political landscape seems pretty unfounded. Fortunately, if you have that hope, you're likely to ignore, refute, or reframe the implications of motivated reasoning.
6. Altered States
In 1978, Paddy Chayefsky published a novel about sensory deprivation. His character had a series of stronger and stronger hallucinations upon entering the sensory deprivation tank until he eventually turned into a monkey, which is the really weird part.
That's why we always carry a copy of Altered States into the waiting room at the floating spa downtown (that's a thing now). So far the staff hasn't said anything to us, but you know it makes them uneasy.
Anyway, that novel, and the cult film that it inspired, are actually pretty accurate. Well, except for the monkey thing. A 2009 study threw 19 subjects who had no existing known mental illness into an "anechoic chamber," which is basically a room that dampens sound and blocks out all light.
The subjects sat there with nothing but their thoughts for 15 minutes. Afterward, five of them said they saw faces in the darkness. Six saw nonexistent objects. Four smelled phantom odors, and two sensed an "evil presence" nearby. Nearly all of the subjects said that they "experienced something very special or important" in the darkened room.
7. When Two Become One
You are yourself and others are others, right? Well, it's complicated. A 2013 study in the journal Social Cognitive and Affective Neuroscience suggests that people who love each other actually blend identities.
We don't mean they start listening to the same music and wearing the same clothes, although that might happen too. On a neurological level, we identify ourselves as our loved ones.
In the study, "Familiarity Promotes the Blurring of Self and Other in the Neural Representation of Threat," researchers stuck subjects in a functional magnetic resonance imaging (fMRI) machine so they could see which parts of their brains lit up during stimulus. Then they threatened the subjects with electric shocks.
Later, they threatened the subjects' friends and loved ones with electric shocks too. Finally, they applied the threat to a stranger. The brain activated incredibly similar areas whether self or friend was threatened. When the stranger was threatened, though, the brain seemed indifferent.
"The correlation between self and friend was remarkably similar," said one of the study's authors, James Coan. "The finding shows the brain's remarkable capacity to model self to others; that people close to us become a part of ourselves, and that is not just metaphor or poetry, it's very real."