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10 Fascinating Ways Our Brains Can Be Manipulated

by Heather
fact checked by Jamie Frater

Scientists are doing fascinating research into how the human brain works. They’re also learning how our brains can be manipulated, whether accidentally or on purpose. Although some of this research has the potential to help certain disabled people, some of it might also be misused in frightening ways.

10The Hot/Cold Effect


Without realizing it, our thoughts and behavior can be affected by whether we feel hot or cold. Two of the most interesting and potentially important research findings concern temperature and criminal behavior. When asked to judge a criminal’s behavior, a person in a hot room was more likely to characterize the criminal as hot-tempered and his behavior as spontaneous. A person in a cold room would probably see the same criminal as cold-blooded and his behavior as premeditated. Obviously, that could have a profound effect on the outcome of a trial or sentencing.

An earlier study, known as the iterated prisoner’s dilemma, had shown that the temperature effect also influences trust and criminal behavior. During the experiment, some participants held a chemical hand warmer while others held an ice pack. Separated and placed in a pretend jail, the test subjects were given the chance to testify against their partner in exchange for a lighter sentence. If both suspects refused to testify, however, both would go free. The results showed that if a test subject held an ice pack, he was twice as likely to testify against his partner. The researchers interpreted that result as indicating that people may trust each other more when warm.

9The Brain Decoder

Experts assume that the same parts of the brain are activated whether you’re reading silently, listening to someone speak, or thinking to yourself. “If you’re reading text in a newspaper or a book, you hear a voice in your own head,” said Brian Pasley of the University of California, Berkeley. “We’re trying to decode the brain activity related to that voice to create a medical prosthesis that can allow someone who is paralyzed or locked in to speak.”

By studying epileptics with electrodes implanted into their brains, Pasley and his team recorded which neurons in the temporal lobe fired when listening to someone speak. After learning that certain sets of neurons reacted to certain frequencies, the scientists tried to build a brain decoder—an algorithm to determine which words someone was hearing based on the specific neurons activated in his brain. If those same neurons fired when someone was thinking, the algorithm theoretically should decode the words they’re thinking.

To see if their algorithm was accurate, the scientists tested it on another group of epileptics with implanted electrodes. First, each test subject read text aloud so that the researchers could create a personalized decoder based on the subject’s brain activity. Each subject then read the same text silently to test the accuracy of the personalized decoder on the person’s neural activity.

Although the brain activity from reading quietly was slightly different than that of reading aloud, the scientists were still able to decode some of the words correctly. But their algorithm needs more work before it’s accurate enough to help the disabled.

8The Marble Hand Illusion

Die Marmorhand-Illusion

Researchers have conducted a lot of experiments to determine how our brains sense our bodies and our positions in space. Usually, they test the impact of visual cues on our perception. But in an unusual experiment, researchers tested the effect of sound and touch on our perception of the material that makes up our bodies. Specifically, the scientists wanted to see if participants would believe that a body part consisted of an inanimate material.

In this experiment, each participant placed his hands on a table in front of him. Then his right hand was tapped with a small hammer. Each time the hammer hit the flesh, the participant would hear the sound of a hammer striking marble. Within minutes, the person felt his hand becoming unnaturally hard and heavy, like a piece of marble. He also experienced less sensitivity. The scientists confirmed this by moving a needle in a threatening manner close to the participant’s hand and seeing how little he reacted.

Unlike our position in space, the materials of our body don’t change. So the scientists were surprised to discover that our brains continually use information from our senses to update its perception of the material that composes our body. They feel this may explain why an amputee’s body can accept an artificial limb so easily.

7The Compassion Pill


We usually think of pills as tools to fight disease. However, researchers at the University of California found that they could manipulate a person’s level of compassion by altering the chemical makeup of the brain. That suggests that social behavior may be influenced by biology more than we previously believed.

In this experiment, participants were randomly given a pill, either tolcapone or a placebo. Usually used to treat Parkinson’s disease, tolcapone extends the effect of the brain chemical dopamine, which is linked to motivation and reward in the prefrontal cortex. Neither the experimenters nor the patients knew who received the drugs or placebos.

After taking their pills, the participants were told to divide money between themselves and an unidentified stranger. Compared to the people who took a placebo, the participants who swallowed tolcapone were much more likely to share their money equally with a stranger. “We typically think of fair-mindedness as a stable characteristic, part of one’s personality,” said researcher Ming Hsu. “Our study doesn’t reject this notion, but it does show how that trait can be systematically affected by targeting specific neurochemical pathways in the human brain.” The team had evidently found a switch in the brain that affects our level of compassion and fair play.

6Extreme Isolation


Isolation, especially for people who are chronically lonely, can cause profound physical effects. It can cause higher rates of infection, elevated blood pressure, Alzheimer’s disease, and dementia. We don’t know exactly why it happens, but isolation provokes a severe immune response that floods our systems with stress hormones and inflammation.

The most disturbing effects appear to be mental. Extreme isolation, such as that of solitary confinement, can wreak havoc with the mind. From slowing time to hallucinations to deliberate brainwashing, the effects can be devastating.

In 1961, a geologist on an expedition to the French Alps stayed underground without daylight for two months to observe the effects on his body. When he surfaced, his team members found that he experienced time-shifting. He thought he was counting out 120 seconds when it was actually five minutes. In another experiment in 1993, Maurizio Montalbini stayed in a cave underground for 366 days. When it was over, he thought he’d only been there 219 days. Researchers have also discovered that people isolated in darkness will usually alter their sleep-wake cycles to 36 hours awake, then 12 hours asleep.

Social isolation can also produce hallucinations. Many experiments on the subject couldn’t be completed because test subjects were having such bizarre symptoms. Prisoners in solitary confinement often experience the same effects. When imprisoned in solitary in Iran, 32-year-old Sarah Shourd saw and heard lots of imaginary things. “In the periphery of my vision, I began to see flashing lights, only to jerk my head around to find that nothing was there,” wrote Shroud about her experience. “At one point, I heard someone screaming, and it wasn’t until I felt the hands of one of the friendlier guards on my face, trying to revive me, that I realized the screams were my own.”

However, some people do cope well and possibly even thrive when isolated. Early explorers and solo adventurers often enjoy their surroundings and the solitude it brings them. Psychologists believe that preparation and mental resilience is key.

5The McGurk Effect

Hear Lady Da Da says Ga Ga Ga.

We use our vision to help us figure out what we’re hearing. But sometimes, that steers us wrong. If you hear someone say “ba,” but they look like they’re saying “ga,” your mind will make you think they’re saying something that sounds closer to what you’re seeing—for example, “da.” Your brain is trying to make sense of the conflict between what you’re seeing and hearing. So we can’t always believe what we hear, although the effect is stronger with certain sounds, especially consonant pairs.

Yet when you close your eyes, you’ll correctly hear “ba” because there’s no visual input to distort your perception. Even if you know what’s happening, you’ll still experience the effect.

The McGurk effect occurs in all languages that have been tested, even if the video and audio are slightly out of sync. It doesn’t matter if the person you see is the opposite sex from the person you hear. The effect also occurs if you think you’re looking at something other than a face, at an extremely small facial image, or if you touch the speaker’s face instead of looking at it. According to researchers, even babies only four or five months old experience the effect.

4The Creativity Jolt


University of Carolina researchers zapped volunteers’ brains with electricity to test its effect on creativity. The goal was to produce alpha oscillations in the frontal cortex of each person’s brain because these types of brain waves are associated with creativity. Alpha oscillations usually happen when we relax and close our eyes. They’re linked to daydreaming, deep thinking, and idea generation.

The 20 volunteers, 19–30 years old, received the popular Torrance Test of Creative Thinking twice, once while they received electrical stimulation to their brains to create alpha oscillations and once with fake stimulation as a control. The volunteers didn’t know when they received the real electrical jolts. Either way, they felt a mild tingle when their tests began.

The results were impressive. The participants averaged about 7.4 percent higher on their test scores when they received the real electrical stimulation. “That’s a pretty big difference when it comes to creativity,” said researcher Flavio Frohlich. “Several participants showed incredible improvements in creativity. It was a very clear effect.”

There may be an easier way to enhance your creativity. According to a study from 2009, colors can affect your imagination. If you want to generate more creative ideas, hang out in a blue room. If you want to be more accurate with activities like proofreading, then go to a red room.



In this experiment, researchers not only created an out-of-body experience for their patients—the scientists then seemingly teleported these patients to various places in the room. They were actually lying in a medical scanner, but their brains were tricked into thinking they had moved.

To determine where your body is, your brain constantly evaluates information from your senses. Earlier research had demonstrated that rats have cells in their brains that function like a GPS to establish where the rodent is in its surroundings, but we aren’t sure if humans have the same thing.

To test how a human brain figures out where its body is placed, each participant in this latest study wore a virtual reality headset while lying in a brain scanner. Using cameras in another part of the room linked to the headset, the participant could see a stranger’s body lying in the foreground with the participant’s body seen in the scanner in the background. To create the out-of-body experience, a scientist touched the body of the participant, who only saw the stranger’s body being touched exactly the same way.

“In a matter of seconds, the brain merges the sensation of touch and visual input from the new perspective, resulting in the illusion of owning the stranger’s body and being located in that body’s position in the room, outside the participant’s physical body,” said researcher Arvid Guterstam. “Your body feels completely normal—you don’t feel as [if you’re] floating around.”

The researchers examined the participants’ brain activity after teleporting them to different parts of the room through this illusion. The scientists decoded where the participants thought they were through patterns of activity in the parietal and temporal lobes of the brain. The researchers also discovered that the hippocampus, where GPS cells are believed to be located, helps us to determine where our bodies are. The posterior cingulate cortex in the brain melds our sense of owning a body with our feeling of self-location.

2The Brainwriter


Still in test mode, the Brainwriter is being developed to allow disabled people to use their minds to write without keystrokes or blinks. Using a headset with electrodes to record brain activity, technology to track eye movements, and software that’s freely available on the Internet, a person can think about one word or idea to make the computer open its writing program. Onscreen, the cursor will then trace the person’s eye path.

The creators of Brainwriter came up with the idea to help Tony Quan, a Los Angeles graffiti artist who lost his muscle control from amyotrophic lateral sclerosis (ALS). The first version of the device required Quan to blink to make the computer go into writing mode. Unfortunately, Quan lost that ability as his illness progressed.

That’s why the current version of Brainwriter uses brain waves recorded by an EEG, which is then read by computer software like it was processing a mouse click. It’s designed to let paralyzed people control their writing in a more effective way than currently available.

1The Invisible Body Illusion

Building on the illusions we’ve already talked about where someone feels a ghostly presence around them or feels as though they’ve swapped bodies, scientists have discovered how to trick your brain to make you feel invisible. In a test involving 20 people, 75 percent experienced the illusion. With the test subject wearing a headset linked to cameras pointing into empty space, a researcher brushed the participant’s stomach while that person viewed a brush stroking empty space in the same way. As the participant’s brain tried to combine what it was seeing and feeling to determine where he was, the person sensed that his body inhabited empty space.

“I am very susceptible to illusions, so for me it worked,” said researcher Arvid Guterstam. “You have a vivid sensation of having a body, but it’s [invisible]. I don’t know what it would feel like to have a phantom body, but I imagine that’s what it’d feel like.”

For the next part of the experiment, the participants were told to look up. Their headset showed some people looking down toward them with stern expressions. The researchers noted that the participants weren’t as stressed by this as they would have been if they felt their bodies were visible. Some experts believe this effect could be used to treat phobias.

In future experiments, scientists want to see how invisibility would influence someone’s moral choices. They also want to see if they can change the participant’s perception of his body in other ways, such as having an invisible face or making an arm feel longer.

fact checked by Jamie Frater