Let’s learn about mind reading

Devices that turn thoughts into actions can help people who aren’t able to move or speak

An illustration of a woman with the top of her appearing to open on a hinge and her pull a thin white string out of a tangled collection of string where her brain would be

Brain implants and brain scans have pulled words, stories and even music from inside people’s heads.

Malte Mueller/fstop/Getty Images Plus

Mind reading is hard. But not impossible.

Modern technology can reach inside someone’s head and pull out their intent. Maybe that intent is to move a robotic arm. Or type something on a computer screen. Such thought-controlled devices can help people who aren’t able to move or speak perform different tasks.

Decoding thought usually requires placing sensors directly on or in someone’s brain. Those implanted electrodes eavesdrop on the electrical signals whizzing between the person’s brain cells, or neurons. Such neural firings carry messages that allow brains to think, feel and control the body.

Using brain implants, researchers have picked up electrical blips in the brain linked to certain words or letters. This has allowed brain implants to transform thoughts into text or speech on a computer. Likewise, brain implants have transformed imagined handwriting into text on a screen. Implanted electrodes have even allowed scientists to turn the neural firings associated with a song in someone’s head into real music.

In a recent study, scientists decoded full stories from people’s brains using MRI scans. This did not require any brain implants. But building the thought decoder did require many hours of brain scans for each person. What’s more, the system only worked on the person whose brain scans helped build it. And only when that person was willing to have their mind read.

So devices that might let someone sneakily read your mind from across the room are still a long, long way off. Still, it’s clear that mind-reading tech is getting more advanced. As it does, scientists are thinking hard about what it would mean to live in a world where not even the inside of your head is completely private.

Want to know more? We’ve got some stories to get you started:

New technology can get inside your head. Are you ready? New technologies aim to listen to — and maybe even change — your brain activity. But just because scientists can do this, should they? (2/11/2021) Readability: 7.7

Neuroscientists decoded a song from brain activity The technique could help improve communication devices for people who are unable to speak. (10/2/2023) Readability: 7.5

Neuroscientists use brain scans to decode people’s thoughts The research may lead to new devices for people who can’t communicate easily. It also raises privacy concerns. (6/28/2023) Readability: 6.7

Robert “Buz” Chmielewski has had quadriplegia since his teens. Electrodes implanted in his brain read his thoughts to control two robotic arms. Here, one robotic arm controls a knife and the other a fork.

Explore more

Scientists Say: Neuron

Scientists Say: Brainwaves

Explainer: How to read brain activity

One day, computers may decode your dreams

New brain implants ‘read’ words directly from people’s thoughts (from Science News)

Brain implants turn imagined handwriting into text on a screen (from Science News)

Maryam Shanechi designs machines to read minds (from Science News)


Word find

MRI scanners aren’t the only machines that help scientists get a good view of the brain. With an interactive from NOVA ScienceNOW, discover how different kinds of imaging technology let researchers and doctors peer inside the brain. 

Maria Temming is the Assistant Managing Editor at Science News Explores. She has bachelor's degrees in physics and English, and a master's in science writing.

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