Can brain-computer interface technology really read our minds?
How close does output from brain-computer interface technology come to actual mind-reading? This psychologist explains the science of BCI in terms of limitations of BCI technology.
BCI imaging acronyms:
- fMRI, functional MRI, measures blood flow;
- EEG, electroencephalogram, measures electrical activity of the brain;
- MEG, magnetoencephalogram, measures magnetic fields generated by neuronal activity of the brain.
EEG – Science fact and fiction
by Genna Erlikhman, September 14, 2010, General Psychology, Neuroscience, Statistics for Social Science
In the last few years, fMRI and EEG have made it into the popular press as tools for reading minds (here, here, here, here and here for a sample), lie-detection (here, here and here), and telekinesis – controlling/ moving objects with our thoughts – (here, here, here, and here). I think there was even a recent episode of House where the doctors were able to display the dreams of someone in a brain scanner. While these and similar technologies have had many successful applications like allowing paraplegics to control wheelchairs and computers or allowing people with locked-in syndrome to communicate (at least give rudimentary yes-no answers to questions), it’s important to know the limitations of these tools and not get carried away into science fiction.
For people concerned about invasions of privacy or some sort of remote scanning of people’s thoughts or personalities, knowing how fMRI, EEG, MEG etc. operate is especially important. First, these tools do not read minds. You can’t plop someone into a brain scanner and be able to determine (right away) whether they are lying or not. And while one of the 60 Minutes clips linked above does show the reporter using EEG without any training to type letters with his thoughts, that device, like almost all others, is simply using a statistical trick in conjunction with some general properties about brain activity to produce its results.
The goal of this post isn’t to explain how fMRI and EEG work in minute detail, but to illustrate how researchers have exploited their properties to achieve what has been interpreted as mind-reading and telekinesis.
So this post ended up being a lot longer than I expected, so here’s a quick summary of what follows for those who just want a short version:
Some places have reported that people can control wheelchairs, robotic arms, computer cursors, etc. with their minds. Simply by thinking “go left” or “stop” the wheelchair will follow the commands it receives given only in thought. Almost all of these demonstrations are not quite true and instead rely on a statistical trick to get the devices to do what people are thinking. The computer picks up on a pattern of brain activity measured with either fMRI, EEG or intracranial electrodes. This pattern can be reliably reproduced by the person. For example, every time you think of stopping, the same part of your brain might become active. The computer then learns to pair this particular pattern with the “stop” command. This is not mind reading! It could just as easily have paired your thoughts of hamsters with the stopping command if those thought patterns could be reliably reproduced. Almost all of the tools mentioned in the articles linked above require this kind of learning on the part of the computer. It is a going to be a long while yet before we can stick someone in a machine and know exactly what they are thinking about. (Although we can sometimes guess about the category of thing that they are thinking about, like house vs. face or animate vs. inanimate object, but also with the proper learning on the part of the machine.)
To see the “long version” which follows the above introduction for this article, and to see varioius links in the original article,visit the full article.
This concludes our first series of articles on brain-computer interface technology. To see the Table of Contents, visit the next page. Please check back for further articles developing this topic.
